Epidemiology

Question 1

Which of the following refers to the incidence rate of dementia in a
catchment area?
A. Number of patients with dementia during a specifi ed time interval
B. Number of newly diagnosed patients with dementia
C. Ratio of the number of newly diagnosed patients with dementia during a specifi ed time
interval to the total population in the same area
D. Ratio of the number of patients with dementia at a given time to the total population
in the same area
E. Number of newly diagnosed patients with dementia who are still surviving at the time
of the survey

Answer 1

C. The incidence of a disease is defi ned as the number of ‘new’ cases diagnosed in a
specifi ed time interval for a specifi ed size of population at risk. The midinterval population usually
determines this population size. For example while calculating the incidence of a disease in 1 year,
the comparison is made against the midyear population.
Incidence in 2008 =
Number of newly diagnosed cases in 2008
Mid 2008 population in an area
Incidence is a rate ratio, that is it is measured against time. It is not a mere number and it is
usually expressed per 100 000 persons in a population, per year. The essential criterion is that the
measure should indicate all new occurrences of a disease within the period of observation in an
area, irrespective of whether the newly diagnosed patients are cured or dead within the period
of observation itself. For an accurate measurement of incidence, two cross-sectional surveys
must be carried out in the same population; one must be at the beginning of a defi ned period
and the other at the end of the same period.

Question 2

In a National Comorbidity Survey carried out in the US, the proportion of
the sampled individuals who ever manifested criteria of panic disorder in
their lifetime was determined. This can be best described as which of the
following?
A. Incidence
B. Point prevalence
C. Lifetime prevalence
D. Lifetime morbid risk
E. Period prevalence

Answer 2

C. Lifetime prevalence is the proportion of individuals in the population who have ever
manifested a disorder, who are alive on a given day. This is ascertained by surveying a population
cross-sectionally and fi nding out if they ever satisfi ed the criteria for a disorder in the past or at
the present time. As one can observe, although this method is commonly used in epidemiological
surveys, it is prone to recall bias. Lifetime morbid risk refers to risk of contracting a disease for
each individual in a birth cohort if they live long enough to reach the average life expectancy of
the population. This must be clearly differentiated from prevalence estimates. Prevalence is largely
a population measure, while lifetime morbid risk is more close to an individual’s chances of being
diagnosed with an illness

Question 3

Using case records, the number of newly diagnosed cases of psychosis in
south-east London was determined for a period of 33 years, between 1965
and 1997. To calculate incidence rate, which of the following is the most
suitable denominator?
A. Total south-east London population in the year 1965 minus number of cases
B. Total south-east London population in the year 1997
C. Census of south-east London population aged more than 16 in the year 1981
D. Census of south-east London population aged more than 16 in the year 1965
E. Census of south-east London population aged more than 16 in the year 1997

Answer 3

C. Incidence is a ratio between the number of newly diagnosed cases within a specifi ed time
period in a population and the total number of people living in the area (total population). To be
accurate, such comparisons must exclude those who are not at risk, though this is generally not
done for non-infectious, non-epidemic diseases such as psychiatric illnesses. It is essential that
the denominator and numerator are not mutually exclusive, that is the diseased group must be a
part of the studied population. Hence, when measuring the incidence of psychosis, the population
above the age of 16 is the relevant denominator. The year 1981 is the midinterval period
between 1965 and 1997

Question 4

Which of the following equations gives the relationship between prevalence
and incidence?
A. Prevalence = duration of disease × incidence rate
B. Incidence rate = duration of disease × prevalence
C. Prevalence = mortality rate × incidence rate
D. Incidence rate = mortality rate × prevalence
E. Prevalence = mortality rate × incidence × duration of disease

Answer 4

A. Prevalence is defi ned as the number of ‘existing’ cases in a specifi ed population for a
period of observation (either cross-sectional observation, called point prevalence, or longitudinal
observation for a specifi ed time, called period prevalence). The existing cases include all new
cases and all cases diagnosed before the observation but still suffering from the disease, but
existing cases excludes those who have been previously diagnosed but are now cured or dead.
For illnesses that are signifi cantly chronic (e.g. schizophrenia), prevalence will be higher compared
to those illnesses that are acute and short lived (e.g. infl uenza), even if the incidence rates are
comparable. Hence the simple expression
prevalence = incidence × duration of illness
explains the relationship between incidence and prevalence.

Question 5

A major cause of mortality in schizophrenia is cardiovascular problems.
If a new class of antipsychotics with favourable metabolic profi le that
reduces cardiac risk is introduced, which of the following could happen?
A. Increase in incidence and prevalence of schizophrenia
B. Increase in prevalence of schizophrenia, but reduced incidence
C. Increased prevalence but unaffected incidence
D. Reduction in both incidence and prevalence
E. Both incidence and prevalence will remain unaffected

Answer 5

C. Certain factors can infl uence incidence and prevalence differently. For example if a new
vaccine is developed to prevent an illness, both incidence and prevalence may come down. If a
cure is developed for schizophrenia, incidence may not be affected but prevalence could drop.
Similarly, if interventions are introduced to reduce mortality in chronic schizophrenia, then
prevalence may paradoxically increase due to longevity of patients. This may not affect incidence
rates directly.

Question 6

Which of the following expresses an incidence rate measured for a
subgroup of a population?
A. Crude mortality rate
B. Lifetime prevalence rate
C. Standardized mortality rate
D. Specifi c mortality rate
E. Survival rate

Answer 6

D. Mortality rates are a special type of incidence rates where ‘death’ is the defi ned ‘case’
of interest. Crude mortality rate is the ratio between number of deaths due to all cause in a
population and total population size. Cause-specifi c mortality rate, for example alcohol-specifi c
mortality, refers to the ratio between the number of deaths due to alcohol in a population and
total population size. A standardized rate is a rate applicable to a hypothetical population with
an adjusted variable, for example age. As population samples are heterogeneous, crude rates
from one population may not be comparable to another population. For example suicide rates in
inner London may not be comparable to rates in rural Yorkshire, as the working-age population
may be higher in London, spuriously increasing suicide rates. Hence, standardized hypothetical
populations are used on which observed rates from a population are applied and adjusted
values are derived. These standardized values are easily comparable, but they are not subgroup
incidence rates.

Question 7

Which of the following correctly expresses proportional mortality rate
due to anorexia nervosa?
A. Number of anorexia-related deaths in a year/ total midyear population
B. Number of anorexia-related deaths in a year/ total number of all cause deaths
C. Number of anorexia-related deaths in a year/ total number of new cases diagnosed
with anorexia in the same year
D. Number of anorexia-related deaths in a year/ 1-year prevalence of anorexia
E. Number of all cause deaths in a year/ number of anorexia-related deaths in the
same year

Answer 7

B. Proportionate mortality rate is a measure of the contribution of a disease to societal
mortality burden. It is given by the ratio between deaths due to a specifi c cause and total number
of deaths in a population. Case fatality rate is the ratio between the number of deaths due to a
specifi c disease and number of persons affected by the disease in a population. It is a measure of
the fatal severity of the disease studied. For example 15 patients out of 100 with anorexia will die
due to its complications. Choice A refers to cause-specifi c mortality rate while choice D refers to
case fatality rate.

Question 8

Which of the following is a major advantage in using standardized
morality rate compared to crude mortality rate?
A. Comparisons between populations is easier with the standardized rate.
B. True value of the number of deaths in a population is given by a standardized rate.
C. Standardized rates can be expressed in meaningful units while crude rates do not
have a specifi c unit for expression.
D. Standardized rates provide an idea about cause of deaths in a population.
E. The accuracy of measurement is increased by using standardized rates.

Answer 8

A. The true value of the number of deaths in a population is obtained using crude mortality
fi gures. Both standardized and crude rates are expressed in the same units of incidence.
Standardized rates are not the same as specifi c rates. Disease-specifi c rates can give an idea
about cause of death in a population. Standardized rates increase comparability, not the accuracy
of measurement of mortality in a population.

Question 9

There are 65 suicides in a population of 1300 patients with schizophrenia.
The rate 65/1300 refers to which one of the following?
A. Proportional mortality rate
B. Cause-specifi c mortality rate
C. Case fatality rate
D. Standardized mortality rate
E. Crude mortality rate

Answer 9

B. This is an example of cause-specifi c (suicide is the cause) mortality rate in a population
(number of schizophrenia patients). If the comparison is between the number of patients died
with a diagnosis of schizophrenia and total number of patients at a given time interval, then
this becomes case fatality rate for schizophrenia. If deaths due to suicides in a population with
schizophrenia are compared with all-cause deaths in the same population then this will be
proportionate mortality due to suicide. A ‘case’ of suicide cannot be identifi ed alive, though
patients who attempted suicides can be identifi ed. So describing a ‘case’ fatality rate for suicide
is meaningless. Nevertheless, method-specifi c case fatality can be derived for various modes of
suicide attempts.

Question 10

Patients with undiagnosed subsyndromal hypomania have clinical
characteristics closely resembling which one of the following diagnoses?
A. Bipolar type 1
B. Dysthymia with depression
C. Depression with stimulant use
D. Bipolar type 2
E. Major depressive disorder

Answer 10

D. In large epidemiological studies, a consistent 1.5% prevalence is quoted for bipolar
disorders. It is unclear whether there is an over-inclusion of depressive disorders and underdiagnosis
of bipolar type 2 disorder in these surveys. Hypomania, being positively appraised
by patients themselves, is often missed in structured, non-clinician interviews. Angst et al., in a
20-year-long prospective study, observed that patients with depression and clinically undiagnosed
subsyndromal hypomania have similar risk factors, course, and outcome compared to bipolar
disorder type 2.

Question 11

In major epidemiological studies, the mean time lag between onset and
clinical treatment for major depressive disorder is determined to be around
A. 3 months
B. 3 weeks
C. 3 years
D. 13 years
E. 3 days

Answer 11

C. According to NESARC (National Epidemiological Survey of Alcoholism and Related
Conditions) the mean age of onset of depression is 30 years, the mean number of episodes in
patients with lifetime major depressive disorder is fi ve, and the mean age of treatment onset for
depression is 33.5 years. This lag of around 3 years is noted in other community samples that
studied treatment seeking for depression. It is currently unclear if untreated depression, as noted
in population surveys, affects clinical outcome in long-term follow-up.

Question 12

Considering the epidemiology of major depressive disorder, which of
the following is incorrect with respect to seeking treatment?
A. Nearly half of men with depression do not get treated.
B. Women seek treatment more often than men.
C. Treatment is sought earlier in developed countries.
D. Less than 20% of depressive episodes do not come to clinical attention.
E. Earlier onset is associated with poorer treatment-seeking behaviour.

Answer 12

D. Nearly 40% of depressive episodes do not come to clinical attention even in developed
nations (NESARC study). The World Mental Health Survey initiative organized by the WHO
revealed that older generational cohorts of depressed people, men, those with earlier age of
depression onset, and those who are living in developing compared to developed countries are
poor seekers of treatment for depression. The situation is even worse for anxiety and substanceuse
disorders. An encouraging fi nding was that those with severe illness sought treatment more
often than those with milder illnesses

Question 13

Major depressive disorder often coexists with personality disorders.
Which of the following groups of personality disorders is most commonly
associated with depression?
A. Paranoid, schizotypal, and schizoid
B. Histrionic, borderline, and antisocial
C. Dependent and anxious avoidant
D. Sadistic and narcissistic
E. Obsessive compulsive and passive aggressive

Answer 13

C. The most common comorbidities with depression in epidemiological surveys are
alcohol use (>40%) and anxiety (>40%). It is noted that cluster C personality disorders, with the
exception of obsessive compulsive personality disorder, show strong associations with lifetime
major depression in large-scale community surveys. In Question 13, choice A refers to cluster
A personality, choice B to cluster B, and choice C to two of the three cluster C personality
disorders. Choice D includes disorders described in DSM IV but not clustered in any of the three
groups.

Question 14

Major depressive disorder often coexists with personality disorders. What
is the proportion of patients with major depression and lifetime
comorbidity of personality disorders in community samples?
A. 10%
B. 60%
C. 75%
D. 3%
E. 30%

Answer 14

E. It is important to note that the prevalence of personality disorders in those who attend
psychiatric services or primary-care services are higher than community prevalence rates. The
rate of personality disorders is recorded to be very high in institutions such as prisons and
psychiatric hospitals providing long-term services. The prevalence of any personality disorder
in community samples is estimated to be around 13% in the UK. The comorbid association of
diagnosable personality disorder and depression was explored in NESARC study, which revealed
30% of depressed patients in the community have a comorbid personality disorder

Question 15

To estimate the number of homeless mentally ill patients, an initial survey
was carried out in a defi ned area of central London and identifi ed patients
were registered. Six months later, another random sampling was carried
out and using the identifi ed proportion of previously registered homeless
mentally ill, reliable population values were deducted. This method of
epidemiological survey is best described as
A. Capture–recapture study
B. Cohort study
C. Cross-sectional survey
D. Audit
E. Comorbidity survey

Answer 15

A. This is called capture–recapture technique. It is useful in estimating the size of a
population that cannot be directly estimated as only a fraction is observable when using sampling
techniques. Initially, a random sample from the population of interest is drawn (e.g. mentally
ill homeless population). After registering these patients they are allowed to mix with the
population (using a registration tag, they can be identifi ed again). When complete mixture with
the total population has occurred, a second random sample is drawn. From the prevalence of the
registered patients in the second sample, the size of the total population may be calculated. This
technique is being used in animal research to provide estimates of census of animals.

Question 16

Who fi rst coined the term comorbidity?
A. Folstein
B. Feinstein
C. Einstein
D. Bradford Hill
E. Gauss

Answer 16

B. The term comorbidity refers to the existence of two different diagnoses at the same
time in an individual. In psychiatric epidemiology, comorbidity is a rule rather than exception.
This high degree of comorbidity is partly due to the overlapping nature of diagnostic entities
in psychiatry. Comorbidity in epidemiological research throws light onto possible aetiological
underpinnings and meaningful outcome variables. Feinstein coined the term comorbidity. The
various types of comorbidity are:
1. Episode (concurrent) comorbidity
2. Lifetime comorbidity
3. Coincidental comorbidity (co-occurrence by chance)
4. Associative comorbidity (risk factor or causal link).

Question 17

Which of the following is the best estimate of the incidence of
schizophrenia if a rigorous systematic review of various epidemiological
studies to date is carried out?
A. 15 per 100 000
B. 1 per 100
C. 4 per 1000
D. 7 per 1000
E. 5 per 100 000

Answer 17

A. The rigorous, systematic review mentioned in the question was carried out by McGrath
and colleagues. Prior to this, in 1986, the WHO published results from the International Pilot
Study on Schizophrenia from seven countries; incidence of ICD 9 schizophrenia was estimated
to be around 16 to 42 per 100 000 in a year. When schizophrenia was narrowly defi ned, this rate
dropped to 7 to 14 per 100 000. McGrath et al. showed a fi vefold difference in the incidence
rates of schizophrenia across various sites in their systematic review and meta-analysis of various
epidemiological studies on schizophrenia. According to this work, it is concluded that the median
global incidence rate of schizophrenia is 15 per 100 000; but this global rate is not as meaningful
as site-specifi c rates due to the degree of variation demonstrated. This view is endorsed by the
AESOP study, which showed signifi cant variation in incidence of schizophrenia among three major
cities in England.

Question 18

The male to female risk ratio for developing schizophrenia is calculated
to be which of the following values?
A. 1 : 1
B. 1.4 : 1
C. 3 : 1
D. 1 : 2
E. 4 : 1

Answer 18

B. The male to female difference in incidence of schizophrenia is estimated to be around
1.4: 1, with more males being diagnosed with the disease. The male excess persists even when
factors such as age range and diagnostic criteria are taken into account; but interestingly this
difference is not borne out when considering prevalence rates, suggesting that different factors
exist in predisposing and perpetuating the illness. It may be related to males having higher
mortality rates than females with schizophrenia or increased predominance of females in
late-onset schizophrenia.

Question 19

The risk ratio for developing schizophrenia in migrants compared to
a native population is
A. 1 to 2.6
B. 1.6 to 1
C. 4.6 to 1
D. 6 to 1
E. 1 to 1

Answer 19

C. Being born in an urban area increases the risk of schizophrenia twofold compared
to individuals born in a rural area. Living in a city is also noted to increase incidence of
schizophrenia. The incidence of schizophrenia is three to fi ve times more common in migrants
than a native population (median 4.6); this difference reduces to 1.8 when considering prevalence
rates. Fluctuations in schizophrenia incidence have been reported over many decades. This may
be related to changing structure of the population. Irrespective of broad or narrow defi nitions,
the incidence of schizophrenia has defi nitely increased in certain urban areas over the last
40 years.

Question 20

The probability of developing a disorder anytime throughout the life
course of a birth cohort is called
A. Lifetime prevalence
B. Lifetime morbid risk
C. Life expectancy
D. Period prevalence
E. Cumulative incidence

Answer 20

B. Lifetime prevalence needs to be distinguished from lifetime morbid risk (LMR). LMR
is the probability of a person developing the disorder during entire period of their life (often
a specifi ed period, defi ned by the life expectancy of the population studied). LMR includes the
entire lifetime of a birth cohort, both past and future, and includes those deceased at the time of
the survey.

Question 21

Which of the following could be estimated using the summation of
age-specifi c incidence rate of schizophrenia throughout the average
life expectancy of a population?
A. Age-specifi c prevalence rate of schizophrenia
B. Lifetime morbid risk of schizophrenia
C. Lifetime prevalence of schizophrenia
D. Cumulative incidence of schizophrenia
E. Period prevalence estimate of schizophrenia

Answer 21

B. For low-incidence disorders such as schizophrenia, summation of age-specifi c incidence rates
gives approximate lifetime morbid risk values. The lifetime morbid risk for schizophrenia is 7.2/1000.

Question 22

The male: female ratio for prevalence of schizophrenia is estimated to be
A. 1 : 1
B. 2 : 1
C. 3 : 1
D. 1 : 2
E. 2 : 3

Answer 22

A. The median prevalence of schizophrenia was 4.6/1000 for point prevalence, 3.3/1000
for period prevalence, and 4.0/1000 for lifetime prevalence. There were no signifi cant differences
observed between males and females, or between urban, rural, and mixed sites with respect
to the prevalence rates of schizophrenia. Migrants and homeless people had higher rates of
schizophrenia and developing countries had lower prevalence rates.

Question 23

The lifetime morbidity ratio associated with schizophrenia is estimated to be
A. 15 per 100 000
B. 1 per 100
C. 4 per 1000
D. 7 per 1000
E. 5 per 100 000

Answer 23

D. The lifetime morbidity risk estimated for schizophrenia is around 7 per 1000 people in
the population

Question 24

The population attributable fraction for seasonal birth in the incidence of
schizophrenia is estimated to be around
A. 30%
B. 50%
C. 2%
D. 10%
E. 6%

Answer 24

D. Population attributable fraction refers to the proportion of a disease in the whole
population that the group exposed to specifi c risk factors represents. It is calculated by fi nding
out the difference between incidence rates in the total population and the exposed population,
and expressing this difference as a proportion of the total population’s incidence rate. It is
different from simple attributable risk, which expresses the difference in incidence rates between
the exposed and non-exposed groups. Winter/ spring birth increases the risk of schizophrenia to
a small extent (RR 1.11), but as the prevalence of birth itself is common in winter/ spring, 10.5%
of all schizophrenia incidences can be attributed to the seasonal birth. The winter/ spring excess
is positively associated with latitude.

Question 25

The incidence rate of an illness varies widely across different countries.
The prevalence measures, calculated at the same time, do not follow the
same pattern of variation but are uneven. Which of the following could
explain this disparity?
A. Different scales were used for measuring new and old cases
B. Recall bias explains the high incidence rates
C. Respondent bias explains the prevalence rates
D. The risk factors for causation and prognosis are different
E. The disease is a fatal condition

Answer 25

D. If the measurement methodologies differ between how a case is ascertained for
incidence and prevalence, then such differences will be uniformly present across various sites.
Recall bias will not infl uence incidences measured using case notes or case registers. On the
other hand, lifetime prevalence rates are susceptible to recall bias. Respondent bias, if present,
must again operate uniformly and should affect various areas consistently, provided the same
methods are used. A fatal disease must reduce prevalence rates uniformly. The most likely
explanation is that the factors predisposing or precipitating the onset are different from the
factors that serve to maintain the illness chronicity.

Question 26

The frequency of adults reporting lifetime presence of mental health
problems in Europe is estimated to be around
A. 1 in 4
B. 1 in 10
C. 1 in 2
D. 1 in 25
E. 1 in 100

Answer 26

A. ESEMeD was the fi rst major multicentre European psychiatric epidemiological study; it was
not conducted in the UK. It used both Composite International Diagnostic Interview (CIDI) version
3.0 (WHO) and Structured Clinical Interview for DSM Disorders (SCID) based clinical diagnosis
(DSM IV criteria). ESEMeD is a part of the World Mental Health Survey Initiative of the WHO. The
results showed that 1 in 4 adults in Europe had a lifetime presence of a mental disorder and 1 in
10 had a mental disorder in the last year; 14.7% had a lifetime history of mood disorder (major
depression only,13%), while 14% had anxiety (specifi c phobia only, 8%), and 5.2% had a lifetime
alcohol-use disorder. The highest rate of mental disorder was in the age group 18–24

Question 27

Considering pathways of care in mental health, which of the following is
not a major fi lter for help seeking?
A. Self-recognition of emotional diffi culties
B. Diagnostic ability of a general practitioner
C. Acceptance rate at secondary care
D. Occupational health initiatives at a place of employment
E. In-patient admission facilities at local psychiatric services

Answer 27

D. Also called the fi lter model, the ‘pathways of care’ model was developed by Goldberg
and Huxley to account for how mental illness interacts with the health-care system. Five levels
of mental illness occurrence were described: the community, the primary-care attendees, the
correctly diagnosed primary-care attendees (in whom the mental illness has been recognized),
the level of the psychiatrist, and that at the level of psychiatric in-patient care. Four fi lters explain
the decreasing incidence when going from the general population to in-patient psychiatric care:
1. At the level of the patient himself or herself (recognition)
2. At the level of the general practitioner (recognition, decision to treat, decision to refer)
3. At the out-patient level of the mental health-care system
4. At the in-patient admission level.
Occupational health resources are not major fi lters in this model.

Question 28

In epidemiological surveys across life span, the term persistence refers
to which of the following?
A. Number of patients with lifetime prevalence who have 12 months prevalence
B. Number of patients with 12 months prevalence who will develop chronic problems
if followed up
C. Number of patients with lifetime prevalence who spent more than 1/3 of life with
the disease
D. Number of patients with lifetime prevalence who spent more than 1/2 of life with
the disease
E. Number of patients with lifetime prevalence who are seeking health-care input

Answer 28

A. Persistence is defi ned as the total number of patients with lifetime prevalence of a
disorder who also satisfy a defi ned period prevalence, say 12 months, criteria at the time of
survey. It is a measure of illness chronicity, response to treatment, and burden.

Question 29

Epidemiological catchment area study is one of the major surveys in
psychiatric epidemiology. Which of the following instruments was used
for clinical diagnosis in this survey?
A. Composite international diagnostic interview
B. Diagnostic interview schedule
C. Schedules for clinical assessment in neuropsychiatry
D. Operational criteria checklist
E. Revised clinical interview schedule

Answer 29

B. The Epidemiological Catchment Area study (ECA) was an investigation of the prevalence
of psychiatric morbidity which was undertaken during 1976–80 in fi ve sites in the USA. More
than 20 000 people were interviewed using the Diagnostic Interview Schedule (DIS). ECA is
regarded as a milestone study in psychiatric epidemiology, after which a new generation of
epidemiological enquiry concentrating on community samples fl ourished. However, ECA was
criticized for its use of lifetime diagnoses, which may be unreliable due to recollection bias. DIS
was the foremost layperson-usable diagnostic instrument designed for psychiatric diagnoses

Question 30

Which of the following could explain the differential outcome for
schizophrenia between developing and developed nations?
A. Economic differences
B. Diagnostic differences
C. Differential methods used in outcome measurement
D. Difference in mode of onset of psychosis
E. None of the above

Answer 30

E. The differential outcome of schizophrenia between developed and developing nations
was fi rst highlighted through the results of the International Pilot Study on Schizophrenia
conducted by the WHO (IPSS). IPSS assessed 1202 persons diagnosed with schizophrenia in
nine countries. The results showed that persons with schizophrenia in the ‘developing’ world
(e.g. Columbia, India, and Nigeria) had better outcomes than persons in ‘developed’ countries
(e.g. Moscow, London, Washington, Prague, and Aarhus in Denmark). In total, 52% of persons
in the developing countries were assessed to be in the ‘best’ outcome category (defi ned as a
single episode only, followed by full or partial recovery) compared with 39% in the developed
countries. There was a claim that acute onset of psychosis, being more common in the developing
nations, confounded the IPSS results, but a subsequent, large-scale, multinational study sponsored
by WHO, excluded mode of onset as being a confounding factor for the observed differences
in outcome. Differential follow-up rates, differential outcome measures, differential sex and age
distribution, and diagnostic ambiguities did not confound the above results, as proved later by
Hopper and Wanderling.

Question 31

Which of the following was a WHO-sponsored survey of outcome
in schizophrenia across different countries?
A. IPSS study
B. DOSMeD study
C. NEMESIS study
D. DEPRES study
E. ECA study

Answer 31

B. Determinants of Outcome of Severe Mental Disorder and the reduction of disability
study (DOSMeD) was conducted by WHO primarily to explore the nature of the differential
outcome between developed and developing nations shown by the International Pilot Study
of Schizophrenia (IPSS). DOSMeD used more rigorous criteria and followed more than 1300
patients in 10 countries and, similar to the IPSS, discovered that the highest rates of recovery
occurred in the developing world. The Netherlands Mental Health Survey and Incidence Study
(NEMESIS study) was not a multinational study. DEPRES stands for Depression Research in
European Society study. DEPRES was the fi rst pan-European, six-country, multinational study on
the prevalence of depression in the general population

Question 32

According to results from the World Mental Health Survey Initiative,
which of the following is true?
A. Developed countries have more mental health problems
B. Severity of mental illness is not proportional to seeking treatment
C. The unmet needs of mental health are equal across all countries
D. The most common mental disorder globally is alcohol misuse
E. Most patients who receive treatment have severe illness.

Answer 32

A. TheWMH Survey Consortium was formed in 1998 and 28 countries were included
in a large, ambitious population survey across countries at different economical stages of
development. The method employed was a multistage household probability survey. Important
fi ndings from the WMH survey initiative were:
1. Prevalence of mental disorders varies widely across countries.
2. Anxiety disorder is the most common (except Ukraine), followed by mood disorders (except
Nigeria and Beijing where substance use was joint second).
3. The USA has highest prevalence rate for any disorder.
4. In all surveyed countries, severity was associated with treatment seeking. Those in developed
countries obtained more treatment than those in developing nations.
5. Interestingly, a substantial proportion of non-cases were receiving treatment. This proportion
was more in developed than less developed nations. This meant that most people receiving
treatment are either mild cases or non-cases and not severely ill.

Question 33

In Europe, the age group with highest prevalence of mental health
problems is
A. Over 65
B. Under 16
C. 18 to 24
D. 25 to 34
E. 35 to 50

Answer 33

ESEMeD is the fi rst major, multicentre, European psychiatric epidemiological study.
ESEMeD is a part of World Mental health survey initiative of the WHO. Six European countries
(not including the UK) were surveyed and a 60% response rate was achieved. The results showed
that the highest rate of mental disorder was in the age group 18–24. Notably, while surveys such
as NCS and NEMESIS excluded elderly populations, ESEMeD had nearly one in two respondents
over 65 years of age.

Question 34

In any given year, the proportion of Europeans who receive antidepressants
for their depression is estimated to be around
A. 20%
B. 40%
C. 60%
D. 5%
E. 90%

Answer 34

A. According to the ESEMeD survey, only 37% of Europeans with mood disorders and 21%
with anxiety disorders sought help from health-care services. Only 21% of depressed patients
received antidepressants in a year. One-third of identifi ed cases had consulted their general
practitioner in the preceding 12 months. Nearly one-third of those who sought help had never
seen a mental health professional. Nearly 21% remained untreated in spite of seeking help.
Comorbidity signifi cantly infl uenced disability and functional impairment.

Question 35

Among people who experience panic attacks, which of the following is
the most common presentation?
A. Agoraphobia with panic attacks
B. Isolated panic attacks only
C. Panic disorder
D. Panic disorder with agoraphobia
E. Physical disorder causing panic attacks

Answer 35

B. Panic can exist in different forms. Major classifi cation systems recognize panic disorder,
agoraphobia, and comorbid panic disorder with agoraphobia. DSM considers panic disorder
as a primary dysfunction while ICD focuses on agoraphobia. To diagnose panic disorder there
must be frequent panic attacks within a specifi ed time interval. It is increasingly realized that
panic attacks can occur without fully satisfying panic disorder criteria. The National Comorbidity
Survey Replication (NCS-R) collected data on four composite groups: isolated panic attacks,
panic attacks with agoraphobia, panic disorder, and panic disorder with agoraphobia. Lifetime
prevalence of panic attacks was only 28% compared to 4.7% who had a diagnosis of lifetime panic
disorder only. Panic with agoraphobia had around 1% lifetime prevalence.

Question 36

The proportion of Europeans with mental health diffi culties who have
sought help from a psychiatrist within the last 1 year is estimated to
be around
A. 20%
B. 40%
C. 60%
D. 5%
E. 90%

Answer 36

A. ESEMeD revealed the degree of unmet health-care needs in Europe. A signifi cant
number of those with depression do not seek treatment. Of those depressed patients who seek
help, most receive care from primary-care physicians. Only 21% of those who seek health-care
support have seen a psychiatrist in the last 12 months.

Question 37

The mean age of onset of panic disorder or agoraphobia is estimated
to be around
A. 22 years
B. 33 years
C. 44 years
D. 55 years
E. 11 years

Answer 37

A. According to the National Comorbidity Survey Replication, mean age of onset of any
panic attack irrespective of diagnosis is around 22 years

Question 38

Women outnumber men in prevalence of most anxiety disorders. Which
of the following anxiety disorders is noted more commonly in men than
women attending health-care services?
A. OCD
B. Panic disorder
C. Agoraphobia
D. Social phobia
E. Specifi c phobia

Answer 38

D. As a general rule, all anxiety disorders are more common in women than men. Notable
exceptions are OCD and social phobia. OCD is more common in boys than girls, but equally
common in adult men and women. Men outnumber women in seeking treatment for social
phobia. It is not clear whether men suffer from a more severe form of social phobia or the level
of impairment caused by social phobia is more for men than women.

Question 39

Which of the following types of specifi c phobia often starts before the
age of 10?
A. Blood injury phobia
B. Space phobia
C. Situational phobia
D. Agoraphobia
E. Animal phobia

Answer 39

A. The estimated lifetime prevalence of blood–injection–injury phobia is around 3.5%. The
median age of onset is around 5 to 6 years. Subjects with blood–injection–injury phobia have
higher lifetime histories of fainting and seizures. Prevalence was lower in the elderly and higher in
females and persons with less education. Patients with this phobia almost never seek psychiatric
help, but they have signifi cantly higher than expected lifetime prevalence of other psychiatric
conditions, including substance use, depression, anxiety disorders, and OCD.

Question 40

In an epidemiological survey, mood state and functional impairment are
recorded using a purpose-built scale. Which of the following can increase
the reliability of such a questionnaire?
A. Increasing the number of questions pertaining to each theme
B. Giving more time to respond to questions
C. Reducing the length of questionnaire to minimum
D. Using two observers for self-rated scales
E. Making the responses unstructured but descriptive

Answer 40

A. Reliability of diagnostic instruments used for interviews in epidemiological surveys will
not change by having two independent observers, if the instrument is self-rated by the patients
themselves. Similarly, descriptive responses could lower the reliability as they are prone to
errors of interpretation. Having a short questionnaire and spending more than usual time on
a questionnaire are not useful strategies to improve the reliability. According to psychometric
principles, the reliability of an instrument could be increased, to a certain degree, if the number
of questions regarding the same theme is increased. This was effectively utilized by the Stirling
County Study when revising the instrument used to detect depression between 1950 and 1970.

Question 41

In the Stirling County Study of the prevalence of depression and anxiety,
the questions used to diagnose depression in 1952 were modifi ed in 1992.
Which of the following best explains why this was done?
A. The concept of depression changed in 40 years.
B. Diagnostic schemes changed in 40 years, necessitating modifi cation of questions.
C. Vernacular terms used in describing depression changed over 40 years.
D. Availability of treatment differed between 1952 and 1992.
E. Severity of depression changed in 40 years.

Answer 41

C. The Stirling County Study is one of the foremost psychiatric epidemiological studies.
It was conducted on cross-sectional samples of the population living in Stirling County,
Canada, in 1952, 1970, and 1992. The epidemiological data was revisited in 2000 and it showed
that vernacular changes in semantic use of terms such as dysphoria could affect results of
epidemiological surveys. Using the same diagnostic system (called DPAX-1) in 1952 and 1970,
no increases in point prevalence of depression were noted, but when the same criteria were
employed in 1992 a drop in prevalence was noted. This was due to a change in use of the term
dysphoria in the studied population; this term went out of use by 1992, leading to a drop in the
sensitivity of the diagnostic instrument DPAX-1. By increasing the number of questions exploring
the mood state and changing the diagnostic system (to DPAX-2), similar prevalence rates were
detected in 1992. Note that though the diagnostic categories changed between 1952 and 1992
this did not have a direct infl uence on the Stirling County Survey, which used a purpose-built
instrument to measure the prevalence.

Question 42

Which of the following epidemiological studies suggested that lifetime
prevalence of depression has remained unchanged over recent decades?
A. National Comorbidity Survey, 1994
B. Epidemiological Catchment Area Study, 1984
C. Stirling County Study, 1992
D. National Epidemiological Survey on Alcohol and Related Conditions, 2002
E. National Comorbidity Survey Replication, 2002

Answer 42

C. Various studies, including NCS and its replication NCS-R, NESARC (National
epidemiological Survey on Alcohol and Related Conditions) and ECA (Epidemiological
Catchment Area Study), have implicated that lifetime prevalence of depression is changing. The
Stirling County Study did not reveal such a signifi cant change in rates of depression. This apparent
change in prevalence could be attributed to the use of different diagnostic instruments. DIS
(Diagnostic Interview Schedule), used in the ECA, and its modifi ed improvised versions used
in other studies relied on recall of lifetime prevalence. Signifi cant recall bias is expected for a
progressively older cohort who will deny or could not recall their depressive episodes. This
might have resulted in a spurious effect. NCS used DSM IIIR (10.1% depression 12-month period
prevalence) while its replication used DSM IV (8.7% depression prevalence), with its clinical
impairment and distress criteria making it possible that less patients will be diagnosed with DSM
IV. In fact, it was later shown that if DSM IV criteria were reapplied then prevalence of depression
drops from 10.1% to 6.4% in the NCS 1994. In addition, NCS excluded all those above age 54
but included a 15 to 17 age group (in contrast to NCS-R), inadvertently choosing the most
prevalent population that might have infl ated the prevalence value. These fl aws were absent in
NESARC, which showed nearly doubled point prevalence estimate of depression from 3.3 to 7%
from 1992 to 2002.

Question 43

The prevalence of hallucinatory experiences in healthy British respondents
from community samples is estimated to be around
A. 4%
B. 11%
C. 33%
D. 19%
E. 0.2%

Answer 43

A. A nationally representative sample of nearly 8500 adults aged 16–74 years living in
private households in Great Britain were interviewed by lay interviewers and were classifi ed
according to their score on the Clinical Interview Schedule–Revised (Psychiatric morbidity survey,
Offi ce of National Statistics). The Psychosis Screening questionnaire was used to collect selfreported
symptoms of psychosis. In the sample, 4.2% said that there had been times when they
heard or saw things that other people could not, but only 0.7% reported hearing voices saying
quite a few words or sentences when there was no-one around that might account for it

Question 44

A sample of healthy British community respondents was surveyed for
self-reported psychiatric symptoms. Most respondents would rate
themselves to have had which of the following symptoms?
A. Hallucinations
B. Hypomania
C. Paranoia
D. Thought insertion
E. Strange experiences

Answer 44

B. In the Offi ce of National Statistics–Psychiatric Morbidity Survey in the UK, a selfreported
instrument, called the Psychosis Screening Questionnaire, was used to detect selfreported
psychotic symptoms. The questionnaire measured symptoms in fi ve domains, namely,
hallucinations, hypomania, strange experiences, paranoia, and thought insertion. Nearly half of the
respondents thought that they experienced at least one hypomanic symptom when questioned,
but, when explored further, more than half of the respondents had valid reasons for feeling very
happy for many days without a break. Only 0.6% reported their friends or relatives commenting
on such a prolonged ‘happy’ state.

Question 45

In epidemiological surveys of preschool children, which of the following
factors observed around age 3 of a child predicts behavioural diffi culties
by age 8?
A. Mother being a house-wife
B. More than two children in the household
C. Maternal depression
D. Deprived neighbourhood
E. Physical health problems at age 3

Answer 45

C. Surveys of preschool children have recorded a high prevalence of problem behaviours.
The most commonly reported problem is that of bedwetting, seen in around 37% of a sample.
Boys and girls show equal prevalence of these problems while those with expressive language
disorders show more behavioural diffi culties. Maternal depression and family discord at 3 years
strongly predict behavioural disorder by the age of 8.

Question 46

Mental health and problem behaviours in a community sample of 10-
to 11-year-old children were recorded in the Isle of Wight study in 1960.
The prevalence of diagnosable psychiatric disorders in this study was
approximately
A. 6%
B. 21%
C. 1%
D. 16%
E. 30%

Answer 46

A. The Isle of Wight Study was one of the earliest epidemiological studies on children,
carried out by Rutter et al. in 1960. In this study, all 10- to 11-year-old children in the Isle of
Wight were surveyed using both parent and teacher questionnaires separately. A 5.7% prevalence
of diagnosable psychiatric disorders was identifi ed. Boys had more problems than girls in the
ratio 2: 1. But only 10% of these children were known to psychiatric services at the time of this
study.

Question 47

Which of the following statements regarding epidemiological surveys
in child and adolescent mental health is true?
A. Psychiatric disorders decrease with increase in age.
B. Adolescents have more burden of psychiatric diseases than younger children.
C. The marital relationship of parents infl uences the severity but not prevalence of
psychiatric diagnoses.
D. Parents and teachers have a high degree of agreement as to which child is having
mental health problems.
E. Most children diagnosed in community surveys were known to mental health services.

Answer 47

B. It is observed that adolescents have more psychiatric diffi culties than younger children.
The Isle of Wight Study was repeated when the cohort was around 14–15 years of age and
the prevalence of psychiatric disorders was found to have increased from 5.7% to 8%. Marital
disharmony predicted development of psychiatric problems by adolescence. A similar study
carried out using a cohort followed up at Dunedin, New Zealand, revealed similar results

Question 48

Questionnaires used in epidemiological surveys can be administered either
by clinicians or trained non-clinicians. Which of the following is true about
these instruments?
A. The rate of psychiatric diagnoses is more when using clinician administered
instruments.
B. The rate of psychiatric diagnoses is the same irrespective of the type of instrument.
C. High level of agreement exists between SCAN (clinician administered) and CIS-R
(layperson administered).
D. Clinician administered instruments are superior for screening purposes.
E. Often a structured lay interview is followed by clinical diagnostic assessment for case
ascertainment.

Answer 48

E. In most of the large-scale epidemiological surveys of the last two decades, screening is
carried out in a population sample using layperson-administered, structured tools to identify
‘caseness’. This is later followed by clinician-led diagnostic assessment to confi rm such cases. It
has been shown repeatedly that layperson diagnostic instruments diagnose more mental illness
than those identifi ed by clinician administered, standardized instruments. The agreement between
these two types of diagnostic tools is poor, around a kappa of 0.1 to 0.4 only, but no single
instrument can be claimed to be superior for case ascertainment purposes.

Question 49

With regard to surveys of suicidal ideation, the transition from ideas to
plans or attempts occurs most frequently in which of the following time
intervals?
A. Within 1 week of the ideation
B. Within 1 month of the ideation
C. Within 3 months of the ideation
D. Within 1 year of the ideation
E. Within 10 years of the ideation

Answer 49

D. Using the data from 17 countries that participated in the WMH survey initiative, the
cross-national lifetime prevalence of suicidal ideation is estimated to be 9.2%. Planning for suicide
is estimated to occur in 3.1% while actual attempts take place in 2.7% of the sample; 60% of
transitions from ideation to plan and attempt occur within the fi rst year after ideation onset.
Consistent, cross-national risk factors included being female, younger, less educated, unmarried,
and having a mental disorder.

Question 50

In epidemiological surveys of suicidal ideation, which of the following
factors is not associated with increased suicidal ideation?
A. Being female
B. Being uneducated
C. Being unmarried or separated
D. Age between 25 to 44
E. Having a psychiatric diagnosis

Answer 50

D. The signifi cant risk factors strongly related to suicidal ideation in cross-sectional samples
are being female, previously married, age less than 25 years, being poorly educated, and having
one or more diagnosable psychiatric disorders. These risk factors are strongly associated with
suicidal ideation rather than conversion of ideas to attempts. In fact, suicides are more common
in men than women across all age groups.

Question 51

Which of the following terms refers to the number of new cases observed
per person-year of observation?
A. Cumulative incidence
B. Incidence volume
C. Incidence density
D. Incidence velocity
E. Incidence ratio

Answer 51

C. The term incidence density refers to the number of new cases observed in a defi ned
period in a population per person-year of observation.

Question 52

Which of the following is the main focus of the current (third) generation
of epidemiological studies in mental health?
A. To measure prevalence of the mental-health burden
B. To measure the specifi c prevalence of individual disorders
C. To measure the attitude of populations towards mental health
D. To measure the burden of care faced by mental-health administrations
E. To identify causal factors for severe mental illnesses

Answer 52

B. To describe the development of psychiatric epidemiology, three ‘generations’ of studies
are distinguished. Around 16 psychiatric epidemiological studies, carried out before World War
II, belong to the fi rst generation. These studies focused primarily on the health-care agencyregistered
prevalence of mental disorders in relation to community characteristics. The second
generation of psychiatric epidemiological studies followed an increased interest in the diagnostic
criteria, classifi cation, and nomenclature of psychiatric disorders after World War II, when
nearly 60 studies appeared. These were mainly fi eld surveys, conducted in unstructured clinical
interviews. Consequently, the reliability of these studies was low. The third-generation studies
started around 1970, with more effort put into increasing the reliability of psychiatric diagnoses.
A major objective of the third-generation studies is to obtain precise estimates of prevalence and
incidence of specifi c mental disorders, whereas second-generation studies focused on mental
ill-health in general. It is claimed that a fourth generation of psychiatric epidemiological studies
is in the making. This includes studies that include comprehensive sets of biological markers
such as brain imaging, cerebrospinal fl uid examinations, blood sampling, etc. in the large-scale,
cross-sectional surveys.

Question 53

When unmet mental health-care needs in the UK are considered, which
of the following is incorrect?
A. Nearly 10% of the population have unmet need for treatment of a psychiatric disorder.
B. Most unmet needs could be managed by a general practitioner.
C. Less than half of all potential needs are met by health-care services.
D. Huge investment in secondary care is required to meet the unmet needs.
E. Unmet needs can be assessed using the Camberwell Assessment of Needs scale.

Answer 53

D. Using the Camberwell Assessment of Needs Schedule, Bebbington et al. determined
the unmet need for psychiatric care to be around 10% of the sample assessed from inner
south London. Less than half of all potentially achievable needs were met in this sample. There
was only partial overlap between diagnosis and an adjudged need for treatment, that is there
was a signifi cant section of the sample that had a need for treatment irrespective of diagnostic
categorization. It was concluded that most of these needs could be met at the primary care level.

Question 54

What is the estimated prevalence of adult ADHD according to the
World Mental Health Survey Initiative?
A. 3.4%
B. 1.4%
C. 34%
D. 14%
E. 8.4%

Answer 54

A. As a part of the WMH Survey Initiative, adult respondents were screened for criteria of
ADHD in a cross-national sample. The estimates of ADHD prevalence averaged 3.4%, with lower
prevalence in lower income countries (1.9%) compared with higher-income countries (4.2%).
A high degree of comorbidity was noted for adult ADHD, and, interestingly, in most low-income
countries the comorbidities were treated more than the ADHD itself. The treatment for adult
ADHD was better in developed countries.

Question 55

Which of the following measures the impact of premature mortality
on a population?
A. Crude mortality rate
B. Disease-specifi c mortality
C. Disability-adjusted life years
D. Years of potential life lost
E. Infant mortality rate

Answer 55

D. ‘Years of potential life lost’ (YPLL) is a measure of the impact of premature mortality
on a population. It is calculated as the sum of the differences between some predetermined end
point (commonly the life expectancy of population or age 65 as standard) and the ages of death
for those who died before that end point. Crude mortality is not specifi c for age distribution of
mortality. The infant mortality rate does not pick up deaths occurring after 1 year of age.

Question 56

Which one of the following studies estimated the differences in incidence
of psychosis in different ethnic groups in the UK?
A. UK 700 study
B. PRiSM Psychosis study
C. ESEMeD survey
D. AESOP study
E. UK household survey

Answer 56

D. AESOP (Aetiology and Ethnicity study of Schizophrenia and other Psychoses) was a
UK-based study on the incidence of psychosis in three major cities—London, Nottingham, and
Bristol. AESOP explored ethnicity differences in the incidence of psychosis in these cities and
found that all psychoses were more common in the black and minority ethnic group, with an
incidence rate ratio of 3.6. When adjusted statistically for confounding factors, this reduced to
an adjusted incidence rate ratio of 2.9. It was also noted that the incidence of all psychoses
was higher in south-east London than Bristol or Nottingham. The UK700 study explored the
differences in outcome between various types of service delivery, that is community teams
and assertive outreach models. The PRISM psychosis study analysed the effect of setting up
community treatment teams on various outcomes and satisfaction measures for service users.

Question 57

According to epidemiological studies on the elderly population, the
prevalence of mental disorders is estimated to be around
A. 10%
B. 2%
C. 50%
D. 5%
E. 30%

Answer 57

E. Lifespan surveys across elderly population are limited. The H70 study refers to a
meticulous, large–scale, longitudinal data collection from individuals over age 70 (born 1901–
1902, observations started in 1971) in Sweden. It included detailed examinations of ageing
and age-related somatic and psychiatric disorders, such as physical examinations performed
by geriatricians, electrocardiograms, chest X-rays, a battery of blood tests, nutritional factors,
anthropometric measurements, psychosocial background factors, and psychometric tests
performed by psychologists. It has provided a rich source of data on elderly populations in
Europe. The psychiatric data available from the H70 show that approximately 30% of those
older than 75 years have mental disorders of some form.

Question 58

Which of the following lifespan studies is secondary research of pooled data
from epidemiological studies estimating the burden of psychopathology in
an elderly population?
A. NEMESIS
B. DEPRES
C. EURO-DEP
D. Isle of Wight Study
E. Epidemiological Catchment Area Study

Answer 58

C. EURO-DEP is a European consortium to study the epidemiology of depression in later
life. This utilizes a secondary research method wherein existing datasets on epidemiology in
late-life depression are pooled and a new instrument, called EURO-D, to diagnose depression
using the various heterogeneous scales from these studies has been devised. The EURO-D scale
was developed from 12 items of the Geriatric Mental State and validated against other scales
and expert diagnosis. Meta-analysis of nearly 14 000 subjects interviewed in various studies
using the Geriatric Mental State, yielded a mean level of depression of 12.3%; the prevalence in
women was 14.1% and men 8.6%. DEPRES (Depression Research in European Society) is the
fi rst large, pan-European survey of depression in the community. It is not secondary research. The
Netherlands Mental Health Survey and Incidence Study (NEMESIS) is a prospective study of
the prevalence, incidence, and course of psychiatric disorders in a sample of Dutch adults aged
18 to 64.

Question 59

With regard to psychiatric epidemiological studies of postpartum women,
which of the following is false?
A. Postpartum depression has no specifi c causal factors.
B. Postpartum depression is not a continuum of postpartum psychosis.
C. The Edinburgh postnatal depression scale is a self-rated scale.
D. Postpartum psychosis occurs following around 1 per 1000 live-births.
E. The recurrence rate of postpartum psychosis is about 1 in 10 pregnancies

Answer 59

E. Postpartum depression has no specifi c causal factors. Though numerous risk factors,
such as social isolation and adverse life events, are associated with the incidence of postnatal
depression, none of these factors are specifi c enough to differentiate postnatal depression
from depression occurring during other phases of a woman’s life. Depression is common in
perimenopausal, peripubertal, and child-rearing or pregnant women. Postpartum depression
is essentially same disease as major depression occurring at other times, with respect to its
classifi catory status. Postpartum depression is not a continuum of postpartum psychosis, which is
more closely associated with bipolar illness. The Edinburgh Postnatal Depression Scale is a selfrated
scale with 10 items. It is a screening tool for detecting depression in mothers. Postpartum
psychosis occurs following around 1 per 1000 live births. The recurrence rate of postpartum
psychosis is about 1 in 4 subsequent pregnancies

Question 60

Considering the epidemiology of suicide in mental health-service users,
in which of the following age groups are suicide rates higher in women
than men?
A. Less than 16
B. 16 to 24
C. 25 to 34
D. Greater than 70
E. None of the above

Answer 60

E. Suicide rates in male mental health-service users are always higher than female service
users irrespective of the age group. The male: female suicide rate is around 3: 1. The gender
difference is most pronounced at age 25 to 34, where nearly 80% are males. The divide is less
steep in those more than 75 years of age where nearly 60% are males

Question 61

A new rating scale for anxiety that is under evaluation has a sensitivity
of 80% and specifi city of 90% against the standard ICD-10 diagnosis.
Which one of the following is correct?
A. Out of 10 truly anxious patients eight will be correctly identifi ed as anxious
by the scale.
B. Out of 10 truly anxious patients nine will be correctly identifi ed as anxious by
the scale.
C. Out of 10 normal volunteers eight will be correctly identifi ed as normal by
the scale.
D. Out of 10 people who test positive using the scale eight will have true anxiety.
E. Out of 10 people who test negative using the scale four will have true anxiety.

Answer 61

A. Sensitivity of a diagnostic test refers to the proportion of diseased subjects who have a
positive test result (true positive rate). If it is 80%, then out of 10 truly diseased (anxious) people,
eight will be correctly identifi ed using the instrument. Specifi city refers to the proportion of the
non-diseased subjects who have a negative test result (true negative rate). So nine out of 10 people
without anxiety will be correctly identifi ed as ‘normal’ using the instrument. Choices D and E
refer to positive and negative predictive values, respectively. Positive predictive value refers to the
proportion of test-positive subjects who are actually diseased. For the given values of sensitivity and
specifi city this is 8/9. Negative predictive value refers to the proportion of test-negative subjects
who are in fact ‘normal’. For the given values of sensitivity and specifi city this is 2/11.

Question 62

Which of the following best describes a receiver–operator curve? It is often
used to
A. Decide the presence of publication bias
B. Decide the optimal cut-off of a screening test
C. Predict the likelihood of a negative result in diagnostic evaluation
D. Measure the survival rates of inception cohorts
E. Test the inter-rater reliability of a new instrument

Answer 62

B. A receiver–operator curve is used to decide the optimal cut-off of a screening test.
A funnel plot is used in systematic reviews and meta-analyses to demonstrate publication
bias. The likelihood ratio of a negative result in diagnostic evaluation is given by a likelihood
nomogram. The survival rates of inception cohorts in a follow-up study are demonstrated
using a Kaplan–Meier curve. Kappa statistics can be used to test inter-rater reliability of a new
instrument.

Question 63

A pilot develops acute manic episode while fl ying with 200 passengers.
After nearly 2 hours of struggle by the rest of the crew, the fl ight is fl own
to safety. The 200 passengers are followed up for development of PTSD
symptoms in the next 2 years. This study can be termed a
A. Case–control study
B. Cohort study
C. Case series study
D. Qualitative study
E. Cross-sectional survey

Answer 63

B. Cohort studies can be differentiated from case–control studies on the basis of the time
of exposure and duration of observation. In case–control studies the exposure has occurred
in the past, unknown to the researcher. Cases and controls are independently recruited and
differential exposure is ascertained in the two groups. In cohort studies, recruitment into a study
takes place as soon as or as and when the exposure occurs (exposure cohort). In this question,
exposure is the traumatic fl ight. Outcome is prospectively observed development of PTSD.
Therefore this is a cohort study.

Question 64

From a nationwide, cross-sectional survey it was found that 8%
of otherwise normal children experience auditory hallucinations
by the age of 11. This 8% of the survey sample was followed up annually
for next 20 years to detect incidence of schizophrenia. This group can be
termed a/an
A. Inception cohort
B. Open cohort
C. Retrospective cohort
D. Random cohort
E. None of the above

Answer 64

A. Inception cohort refers to all individuals assembled at a given point based on some factor,
for example common demography or common life experience. In the above example, following
a survey, a group of individuals with similar experience of auditory hallucinations are followed
up prospectively. Hence they constitute an inception cohort. Open cohort refers to recruiting
the cohort over an extended period of time instead of choosing the same point in time. In most
open cohorts the individual subjects are followed up for variable time intervals until the study is
completed.

Question 65

X is strongly associated with Y. A study investigates whether X causes Y.
Which one of the following weakens the claim for a causal association
between X and Y?
A. Consistency of association between X and Y
B. Dose–response relationship between X and Y
C. X always precedes Y
D. U, V, and W are well-established effects of X
E. X and Y are biologically related phenomena

Answer 65

D. Widely known as the Bradford Hill’s criteria for causal association, demonstration of the
following helps to ascertain cause–effect relationships:
1. Temporal association: The cause X must have occurred before the effect (disease) Y.
2. Dose–response relationship: the higher the X, the more the Y.
3. Consistency of association: whenever Y is present X is present and vice versa.
4. Strength of association must be high.
5. Biological plausibility: X has a biologically sensible causal pathway leading to Y.
6. Specifi city: X is associated with Y only, not a wide range of other diseases.
7. There must be experimental evidence to support the claims

Question 66

An astute old age psychiatrist wants to know the prevalence of dependent
personality disorder among the elderly population in his catchment area.
The most appropriate research method he will be employing is
A. Case–control study
B. Cohort study
C. Case series study
D. Qualitative study
E. Cross-sectional survey

Answer 66

E. Cross-sectional surveys are best suited for calculating epidemiological measures such as
prevalence rates. To detect incidence rates the cross-sectional survey must be conducted at two
different time points (to ascertain ‘new’ cases). To detect point prevalence rates a single crosssectional
study should be suffi cient.

Question 67

Regarding the risk factors for adolescent alcohol problems, which of the
following accounts for high attributable risk?
A. Externalizing symptoms in childhood
B. Maternal alcohol consumption
C. Poor school performance
D. Lack of friends
E. Being a single child

Answer 67

B. Studies show that exposure to maternal drinking in adolescence is a strong risk factor for
the development of alcohol problems in early adulthood. For males and females, no association
was found between either birth factors or childhood factors and a lifetime diagnosis of alcohol
disorders at age 21 years. Externalizing symptoms and maternal factors at age 14 years were
signifi cantly associated with alcohol problems. For youths aged 14 years, maternal moderate
alcohol consumption accounted for the highest percentage of attributable risk among those
exposed.

Question 68

A new test being evaluated to predict treatment response in geriatric
depression utilizes neuroimaging techniques. The overall results of the test
are very close to that observed on longitudinal follow-up after treatment
(gold standard) but individuals vary widely in the magnitude of the results
produced. Which one of the following correctly describes the properties of
this test?
A. Precise and accurate
B. Precise but not accurate
C. Not precise but accurate
D. Neither precise nor accurate
E. Accurate and sensitive

Answer 68

C. Accuracy refers to the extent to which results are close to the truth. In psychometry, it
is used interchangeably (and controversially) with the term validity. Precision refers to the extent
to which results are consistent or close to each other and hence are reproducible. The new test
produces results that are close to the truth as observed from the gold standard results. Hence it
is accurate, but the magnitude of measured outcome varies widely among the tested population.
Hence it is not precise.

Question 69

The lifetime prevalence of OCD is estimated to be around
A. 0.5–1%
B. 1–2 in 1000
C. 2–3%
D. 8–10%
E. 10–15%

Answer 69

C. Though OCD was previously thought to be quite rare, recent evidence suggests this is
not the case. A lifetime prevalence rate of 2–3% has been suggested. OCD is among the top 20
causes of illness-related disability for people between the ages of 15 and 44. The age of onset of
OCD is usually mid-to-late twenties. The female to male ratio is said to be more or less equal,
though some studies suggest an excess in females. The mean age of onset for men is around
22 years, for women this is slightly delayed—around 26 years. The illness tends to be secret in
most patients with a delay of several years before treatment is sought. OCD is the fourth most
common mental illness in world. The disorder presents with comparable prevalence rates across
various countries, with some cultural specifi city to the content of obsessions.

Question 70

The prevalence of diabetes is higher among people with schizophrenia.
Which of the following statements is correct with respect to the
association between diabetes and psychiatric disorders?
A. Diabetes is two to four times more prevalent in schizophrenia.
B. Patients with treatment-resistant schizophrenia are less likely to be screened for
diabetes.
C. There is an unusually low rate of family history of type 2 diabetes in schizophrenia
patients.
D. Rates of impaired glucose tolerance in drug-naı¨ve fi rst-episode schizophrenia is less
than in the general population.
E. Schizophrenia is the only mental disorder showing an established association with
diabetes.

Answer 70

A. The prevalence of diabetes is higher in not only schizophrenia but also in patients with
bipolar I disorder (26%) and schizoaffective disorder (50%), independent of psychotropic drug
use. Genetic factors have a key role in the association between schizophrenia and diabetes; up
to 50% of individuals with schizophrenia were found to have a family history of type 2 diabetes
in a study. The increased risk is demonstrated regardless of antipsychotic medication use. Due
to frequent screening and blood test in the treatment-resistant group, the detection of hidden
impaired glucose tolerance may be higher. Diabetes is estimated to be at least two to four times
more prevalent in schizophrenia than in the general population, but signifi cant variability is noted
in the actual prevalence rates reported. Diffi culties in developing a wide-reaching screening
programme may be a source of this variability.