Reliability of the DSM

• Looked at agreement in diagnosis on admission and on release
• 998 patients
• Israeli hospital

Findings:

• Kappa for mood disorder = 0.68
• Psychotic patients = 0.62

Reliability is high as a kappa of 1 would mean complete agreement in diagnosis

• Looked at methodological problems with studies testing DSM

• Use of interviews and questionnaires: interviewers training was poor- lacked commitment and skills

• research setting- can't be generalised to setting of clinic- meaning diagnosis is NOT accurate

Not reliable 

• Affect of culture on diagnosis

• Psychiatrists in NYC = 2x as likely to diagnose SCHIZOPHRENIA

• Psychiatrists in London = 2x as likely to diagnose MANIA or DEPRESSION

• Both were shown same video taped clinical interview!!

Cultural factors may affect reliability of diagnosis due to difference in beliefs and norms.

• Reliability of DSM III 

• Researchers looked at histories of patients previously diagnosed with schizo

• High level of agreement for diagnosis (re-hospitalisation)

Highlights the RELIABILITY of the DSM III

• there have been different diagnosis' which show psychiatrists may be SUBJECTIVE when giving diagnosis- personal opinion

• Misdiagnosis may also be deliberate- some institutions only admit people with certain problems, may misdiagnose to admit someone or to send them away?

DSM NOT RELIABLE

• If there is unreliability in classification system- could result in unreliable diagnosis

• Severe consequences- could affect selection of treatment and also communication with patient

E.g; could be given treatment for no reason...or not given treatment when need it