Discuss prevalence rates and disorders (Brown & Harris and N-H)

Question 1

Discuss prevalence rates and disorders (Prevalence rates of disorders measures how common…)

Answer 1

Major Depressive Disorder (MDD) is a mood disorder that is characterized by prolonged (longer than a few weeks) feelings of sadness, loss of interest in daily activities and lack of appetite.

• We categorize MDD as abnormal behavior – behavior that is deviant and maladaptive, causes feelings of distress to an individual

Prevalence rates of disorders measures how common a psychological disorder is in a specific population (proportion).

Incidence rates are also studied by researchers as a measure of the NUMBER OF NEW CASES of a characteristic that develop in a population in a specified time period (dividing no. of reported cases by total population) → we measure this to understand how quickly the disorder occurs eg. For example, the prevalence of major depressive disorder is higher among women than men in Western societies.

It is constantly changing because of globalization and effects of cultural norms

Question 2

How is prevalence rate calculated?

Answer 2

Measuring the presence of disorder in a sample of the population selected randomly, then dividing the no. of population IN A GIVEN TIME PERIOD

Obtain data by:

• Interviews
• Self reported questionnaires/surveys

Question 3

Claim 1: Vulnerability Model “One reason for differences in prevalence rates is that there are different levels of risk factors for different populations.” Brown & Harris

Answer 3

Demonstrated by… Vulnerability Model - Risk factors vs protective factors

Brown & Harris

AIM: How sociocultural or environmental factors may play a role in gender differences (women 2x as likely to develop depression as men)

METHOD:

1. 458 women in London surveyed on life and depressive episodes.
2. Focused on particular struggles faced by women and rated in severity by independent researchers.
3. Conducted semi-structured interviews w/ questions focusing on biographical details.

FINDINGS: 85% of all women became clinically depressed (nearly 90% after an adverse life event or a serious difficulty such as an abusive relationship)

Social class - what the husband’s job was - played a big role in depression of women with children

Researchers identified that:

1. Protective factors → intimacy with husband led to higher levels of self-esteem despite stress
2. Vulnerability factors → loss of a parent, unemployment, lack of social support

LINK: Risk factors ↔ prevalence - risk factors can change over time + not the same for everyone

Combination of genetic vulnerability (diathesis) increases likelihood of depression

STRENGTHS: Semi-structured interviews - more open-ended, relatively large sample

WEAKNESSES: Only females were included within the sample, cannot establish a C+E r/s it is only correlational.

Prevalence rates of disorders may be calculated through the use of hospital records or through carrying out interviews within a population –> One of the problems with relying on hospital records is that it may actually underestimate the prevalence of a disorder, since many people who may suffer from a psychological disorder may not seek out medical help. When using interviews, there is the problem that although depressive symptoms may be identified, there is often no formal diagnosis against the criteria, which may lead to a false inflated prevalence rate. Even in cases where only diagnosed patients are used, because we know that there are problems with the validity and reliability of diagnosis, prevalence rates may always be open to question.

Question 4

Claim 2: Nolen-Hoeksema’s Theory of Rumination “The more we experience a symptom, the more cognition we use to evaluate it, the more we become depressed”

Answer 4

Self-reported subjective stress is more prevalent in women yet higher acute stress responses is more prevalent in men

AIM: Role of rumination on depressive symptoms –

METHOD:

1. 1132 participants in San Fran
2. Interviewed 2x 1 year with a 90-min clinical interview
3. Tests – Beck Anxiety and Beck Depression (automatic negative thinking)
4. Rumination and coping questionnaire (How much are you thinking about your negative feelings?)

FINDINGS: Potential MDD indivs had higher score of rumination.

Improvement of depression indivs had lowered rumination compared to chronically depressed

LINK: Shows prevalence of depression amongst women (twice as likely) due to rumination leading to an increase in exhibited depressive symptoms – which AFFECTS PREVALENCE RATES as people might not want to seek medical help due to rumination

STRENGTHS: Supports N-H Theory, multimethod research - used both questionnaire + interview

WEAKNESSES: Self report – response biases

Question 5

Limitations of Prevalence Rates

Answer 5

• There are many factors that affect prevalence rates
  • Even if the prevalence of a depression increases or decreases as a result of a societal or environmental change, it is not possible to establish a cause-and-effect relationship as there are many incidents of false self-diagnosis (certain populations where there is a sig. increase in eating disorders, due to the culture)
• Comparing prevalence rates over time is problematic because there are so many variables that could account for any difference.

Question 6

Parker, Cheah and Roy (Effect of globalization on prevalence rates)

Answer 6

Explanatory Model → constant evolution of globalization, explanatory models shift over time. Cultures create socially acceptable sets of symptoms of mental distress, so there are cultural variations in the presentation of depression. Since cultures are continually evolving, especially in the era of globalization, these explanatory models may change over time.

Prevalence rates do not consider diferent classification systems, such as DSM-5 (Western) or CCMD-3 (China), thus rates can be higher or lower dependant on this fact

AIM: What extent of symptoms of MDD differed between Chinese and Australian patients? Chinese patients tend to somaticize (physical symptoms rather than mental) - stigma?

METHOD: 50 Malaysian Chinese participants and 50 Australian participants diagnosed with MDD

1. Questionnaire based on MOOD & COGNITION (Western diagnostic tools for depression) and SOMATIC SYMPTOMS (Oberved by Singaporean psychiatrists)
2. Judge how many times they have experienced some of the symptoms in the past week and how distressing it was

FINDINGS: Somatic symptom was more of a warning for Chinese participants than Australians compared to emotion such as helplessness or depressed mood, which AFFECTS PREVALENCE RATES = difference in cultural symptoms

LINK: Suggests the influence of culture in perception of MDD, in collectivist cultures such as China, personal importance on one’s emotions is less significant and even stigmatized
**

STRENGTHS: Cross-cultural validity as the questionnaire was translated and combined different cultural criteria for MDD

WEAKNESSES: Only done on two cultures and Malaysia is a Westernized society, variables like degrees of somatization and self-reporting bias need to be kept in mind – which can affect prev rates

Question 7

Prevalence Rates & Disorders Conclusion

Answer 7

Prevalence rates are important in understanding

• The extent of which a disorder affects population, which can help guide the allocation of resources for prevention, diagnosis, and treatment.
• Patterns in mental disorders, such as age, gender, and ethnicity, which can inform targeted interventions and help reduce disparities in access to care.
• Changes in prevalence rates can also be used to generate hypotheses about the aetiologies of disorders.