Diagnosis of schizophrenia: consistency across information sources and stability of the condition.

BACKGROUND: The Social Security Administration is considering whether schizophrenia may warrant inclusion in their new "Compassionate Allowance" process, which aims to identify diseases and other medical conditions that almost always qualify for Social Security disability benefits simply on the basis of their confirmed presence. This paper examines the reliability and validity of schizophrenia diagnosis, how a valid diagnosis is established, and the stability of the diagnosis over time. A companion paper summarizes evidence on the empirical association between schizophrenia and disability, thus leading to this paper that evaluates how valid clinical diagnoses of schizophrenia are.
METHODS: Literature review and synthesis, based on a workplan developed in an expert meeting convened by the National Institute of Mental Health and the Social Security Administration.
FINDINGS: At least since the introduction of the 3rd edition of the American Psychiatric Association's Diagnostic and Statistical Manual (DSM-III) in 1980, diagnoses of schizophrenia made by mental health specialists are valid, reliable, and stable over time, across community as well as academic practice settings, and across different assessment methods. These analyses are particularly valid during the time-frame relevant to social security awards: at least 2 years after the initial stages of illness. We could not find studies that have evaluated the validity or reliability of schizophrenia diagnoses made exclusively by primary care providers (vs. mental health professionals). DISCUSSION: In the post-DSM-III era, schizophrenia diagnosis-using modern diagnostic criteria-is valid and reliable when performed by doctoral-level mental health specialists (i.e., psychiatrists and psychologists), in community as well as academic settings.