Occurrence and treatment of depressive comorbidity/cosyndromality in schizophrenic psychoses: conceptual and treatment issues.

Depressive symptoms are a common feature of schizophrenic disorders, a fact that has become increasingly apparent over the last two decades. Apparently the introduction of standardized rating scales in cross-sectional and longitudinal investigations played an important role in the recognition of the relevance of depressive symptoms. They can be interpreted as being cosyndromal or comorbid, depending on the conceptual perspective applied. This is not simply a difference in terminology but is of great aetiopathogenetic relevance. Of particular clinical relevance is the observation that schizophrenic patients with concomitant depressive symptoms have a greater risk of suicidality or an unfavourable disease course. For this reason it is important that sufficient attention is paid to the diagnosis and treatment of depressive symptoms occurring during schizophrenic psychoses. Besides treatment with antidepressants, modern neuroleptics are of great importance in this context as they are more efficacious than classical neuroleptics in treating depressive symptoms.