Diagnosis And Classification Of Schizophrenia Flashcards
What % of the population is affected by serious mental disorders?
1%
Schizophrenia is more common in what 3 groups?
Males, city-dwellers, lower socio- economic groups
To diagnose a specific disorder, what do we need to be able to do?
We need to be able to distinguish one disorder from another.
What is classification?
Identify symptoms that go together = a disorder
What is diagnosis?
Identifying symptoms and use classification system to identify the disorder ( eg depression, OCD, schizophrenia etc,)
What are the 2 main classification systems in use?
DSM _5→ One positive symptom must be present (delusions, hallucinations or speech disorganisation,,,)
ICD- 10 → two or more negative symptoms are sufficient for diagnosis ( eg abolition and speech poverty)
What is one strength of the diagnosis and classification of schizophrenia?
Good reliability → a reliable diagnosis is consistent between clinicians (inter -rater) and between occasions (test-retest)
Osorio et al,19 report excellent reliability for sz diagnosis (DSM-5) → inter-rater agreement of +97 and test-retest reliability of +92. Meaning the diagnosis of sz is consistently applied.
What is one weakness and what is its counterpoint?
Low validity → criterion validity involves seeing whether different procedures used to assess the same individuals arrive at the same diagnosis.
Cheniaux et al had 2 psychiatrists independent assess the same 100 clients. 68 were diagnosed with sz with ICD and 39 with DSM. Meaning schizophrenia is either over - or under - diagnosed, suggesting that criterion validity is low
Counterpoint - in the osorno study there was an excellent agreement between clinicians using different procedures both derived from the DSM system. Meaning that the criterion validity for sz is good provided it takes place within a single diagnostic system.
