Introduction to schizophrenia Flashcards
What is schizophrenia?
A severe mental disorder, where contact with reality and insight are impaired
Who is schziophrenia most commonly diagnosed in?
- 1% of the population
- Men
- City-dwellers
- Lower socio-economic groups
How does the medical approach diagnose disorders?
- We must distinguish one disorder from another
- This is done by identifying clusters of symptoms that occur together, and classify as one disorder
What are the 2 main systems of classifying mental disorders?
1) DSM-5 (American Psychiatric Association’s Diagnostic and statistical manual)
2) ICD-10 (World Health Organisation’s International classification of disease)
What is the difference in diagnosing schizophrenia between DSM-5 and ICD-10?
- DSM-5= 1 positive symptom must be present
- ICD-10= 2+ negative symptoms must be present
What are the 2 positive symptoms?
- Hallucinations
- Delusions
What are hallucinations?
- Unusual sensory experiences
- Some are related to environmental events
- May be experienced in relation to any sense
What are delusions?
- Irrational beliefs (aka paranoia)
- Common delusions involve being an important historical, political, or religious figure
- May involve being persecuted
- People believe they are under external control
- Makes people behave in ways that make sense of them, but appear bizarre to others
What are the 2 negative symptoms?
- Speech poverty
- Avolition
What is speech poverty?
- Changes in patterns of speech
- Emphasis on reduction in amount/quality of speech
- May be accompanied by a delay in verbal responses
- Emphasis now placed on speech disorganisation (speech= incoherent, topic change mid sentence)
What is avolition?
- Finding it difficult to begin/keep up with goal-directed activity
- Reduced motivation to carry out range of activties
- Andreason- 3 signs: poor hygeine/grooming, lack of persistence in work/education, lack of energy
.
Strength-
I- Good reliablity
D- Osorio et al report excellent reliability for schizophrenia diagnosis in 180 individuals, using DMS-5. Pairs of interviewers achieved inter-rater reliability of +.97, and test retest reliability of +.92
E- Means we can be sure that diagnoses are consistently applied
Limitation-
I- Low validity
D- Cheniaux et al- 2 psychiatrists independently assessed the same 100 clients, using ICD-10 and DSM-5. Found 68 were diagnosed with schizophrenia under ICD-10 and 39 under DSM-5
E- Suggests schizophrenia is either under or over diagnosed, so criterion validity is low
Strength-
I- Good criterion validity
D- Osorio- excellent agreement between clinicians, when 2 measures were used, both derived from DSM-5
E- Means criterion validity is good, provided diagnosis occurs within a single diagnostic system
Limitation-
I-Co-morbidity
D- Commonly diagnosed with other conditions. Buckley et al found 50% of those diagnosed, also had a depression diagnosis, 47% co-morbid with substance abuse, and 23% with OCD
E- Problem for classification, as it means schizophrenia may not exist as a distinct condition
Limitation-
I- Gender bias in diagnosis
D- Since 1980s, men more commonly diagnosed with schizophrenia than women. Fishcer and Buchanan= 1:1.41 ratio. May be because women are less vulnerable, due to genetic factors. Cotton- women are more undiagnosed as they have closer relationships and thus support. This leads to schizophrenic women functioning better than men
E- Evidence of gender bias, meaning women may not be receiving treatment and services
Limitation-
I- Culture bias in diagnosis
D- Some symptoms have different meanings in different cultures. E.g: Haiti= hearing voices is seen as communications from ancestors. Pinto and Jones- British people of African-Caribbean origin are 9x likely to receive diagnosis than White British people, but living in African-Caribbean culture do not. Escotar- culture bias leads to an overinterpretation of symptoms in black British people
E- Means British African-Caribbean people may be discriminated against by a culturally-biased diagnostic system
Limitation-
I- Symptom overlap
D- Both schizophrenia and bipolar disorder involve positive symptoms (delusions) and negative symptoms (avolition). Suggests that schizophrenia and bipolar may not be 2 different conditions, but variations of a single condition
E- Means schizophrenia may not exist as a distinct condition, and even if it does, it is hard to diagnose, so classification/ diagnosis are flawed
What are the 3 differences between ICD-10 and DSM-5?
- DSM-5= 1 +ve symptom, ICD-10= 2+ -ve symptoms
- DSM-5= dropped subtypes, ICD-10= uses subtypes (i.e. paranoid)
- DSM-5= speech disorganisation= +ve, ICD-10= speech poverty, -ve
What was Rosenhan’s procedure?
- Aimed to see if psychiatrists could identify the difference between sane and insane patients
- They were admitted into the hospital, then acted normally- note-taking (7-52 days stay, 19= average)
- Study 2= one hospital asked him to send pseudopatients over 3 months
What were Rosenhan’s findings and conclusions?
- Study 1= 11/12 hospitals and 7/8 pseudopatients diagnosed as schziophrenic
- Study 2= 41/193 patients suspected to be imposters
- Highlights validity issues with DSM-2= led to reform
What were the strengths/limitations with Rosenhan’s study?
- Poor external validity (small sample- population validity)
- Poor temporal validity (DSM-2= outdated)
- Culture bias (American pps)
- Good reliability= standardised procedure
- Poor reliaility= some did not follow training- relationship with nurse
- Poor internal validity- Ketty= faking- tells us little
- Unethical- psych harm, lack informed consent, deception
What is the difference betwee positive and negative symptoms?
- Positive= add something new (i.e. hallucinations)
- Negative= take away something (i.e. avolition takes away motivation)
