Post-Schizophrenic Depression Diagnostic Criteria

Please see our separate note on Treatment, Mental Disorders and Basic Science for important caveats on the role and definition of diagnostic criteria.

ICD-10 Criteria for Post-Schizophrenic Depression

The following information is reproduced verbatim from the ICD-10 Classification of Mental and Behavioural Disorders, World Health Organization, Geneva, 1992.

F20.4 Post-Schizophrenic Depression

A depressive episode, which may be prolonged, arising in the aftermath of a schizophrenic illness. Some schizophrenic symptoms must still be present but no longer dominate the clinical picture. These persisting schizophrenic symptoms may be "positive" or "negative", though the latter are more common. It is uncertain, and immaterial to the diagnosis, to what extent the depressive symptoms have merely been uncovered by the resolution of earlier psychotic symptoms (rather than being a new development) or are an intrinsic part of schizophrenia rather than a psychological reaction to it. They are rarely sufficiently severe or extensive to meet criteria for a severe depressive episode, and it is often difficult to decide which of the patient's symptoms are due to depression and which to neuroleptic medication or to the impaired volition and affective flattening of schizophrenia itself. This depressive disorder is associated with an increased risk of suicide.

Diagnostic Guidelines

The diagnosis should be made only if:

1. the patient has had a schizophrenic illness meeting the general criteria for schizophrenia (see introduction to F20 above) within the past 12 months;
2. some schizophrenic symptoms are still present; and
3. the depressive symptoms are prominent and distressing, fulfilling at least the criteria for a depressive episode, and havew been present for at least 2 weeks.

If the patient no longer has any schizophrenic symptoms, a depressive episode should be diagnosed. If schizophrenic symptoms are still florid and prominent, the diagnosis should remain that of the appropriate schizophrenic subtype.