SZ 19 Reliability and validity of diagnosis 2

Identify the meaning of each of the following

A When a diagnosis is consistent between psychiatrists

B When a person has more than one condition at the same time

C When a psychiatrist diagnoses a condition correctly

D When two conditions have some effects in common

A When a diagnosis is consistent between psychiatrists = reliability

B When a person has more than one condition at the same time = comorbidity

C When a psychiatrist diagnoses a condition correctly = validity

D When two conditions have some effects in common = symptom overlap

Explain key issues / research on symptom overlap in the diagnosis and classification of schizophrenia (4)

* Similar (descriptions of) symptoms of different disorders in manuals

* Positive symptoms of SZ ≈ mania

* Negative symptoms ≈ depression

* Lead to invalid diagnoses => wrong treatment

Enlarge image for examples of similar symptoms

Explain key issues / research on comorbidity in the diagnosis and classification of schizophrenia (5)

* Having more than one disorder

(even without symptom overlap, e.g., OCD)

* High rates for SZ with range of disorders

* Illnesses cause each other or have same cause

* Illnesses hide each other

* Lead to invalid diagnoses => wrong treatment

Explain key issues / research on gender bias in the diagnosis and classification of schizophrenia (6)

* Women diagnosed less often, males 40% more often

* Change in DSM rules for DSM III

* Symptoms must interfere with functioning for a diagnosis

* Led to growth of difference between women and men

* Due to: better functioning or doctors interpretation of women's behaviour as better functioning

* Underdiagnosis => no treatment when needed

Explain key issues / research on cultural bias in the diagnosis and classification of schizophrenia (5)

* Afro- Caribbeans 3x more likely to have a diagnosis of SZ

* Genuinely high rates due to more stress / prejudice?

* Due to bias / lack of cultural knowledge?

* e.g., doctors interpret communicating with dead as sign of SZ

* Overdiagnosis => unnecessary treatment