The observation and debates concerning the coexistence of depression and schizophrenia date back to Kraepelin and Bleuler. Both recognized that among the basic symptoms of ‘dementia praecox’ and "schizophrenia", are the flattening of affect and the depressed affect and both included in their clinical descriptions of schizophrenia the depressive symptoms. During the recent years this observation has been made official, with the inclusion of diagnoses like schizoaffective psychosis as well as the post psychotic or post schizophrenic depression in the international disease categorization systems DSM and ICD. Several theories have been proposed to explain the relation of depression and schizophrenia, especially when there both appear simultaneously in the same patient. Depression can be present during the prepsychotic prodromal phase, during the acute phase or after the remission of the psychotic features. In addition depressive symptoms could be part of the clinical picture of chronic stabilized patients. Depression in schizophrenia is defined in differentways, i.e. through the criteria of DSM and ICD, through the relevant items of psychopathological scales or through the total rating of depression scales if the score exceeds a certain cut-off. Since the existing depression scales have been created to evaluate depressed patients and therefore there were questions of validity of their use in schizophrenic patients, recently it has been proposed a special scale to evaluate depression specifically in schizophrenic patients (Calgary Depression Scale for Schizophrenia). This scale has been standardized in a Greek sample. In general, according to the existing studies 7–70% of all schizophrenic patients suffer from some form of clinically relevant depression and the median frequency from all the available studies is 25%. The frequency of depression in new schizophrenic patients is 21–24% during the acute phase and it seems that this frequency progressively decreases with the time and stabilizes around 8% in remitted patients. These frequencies may vary upwards depending on the definition of depression. One in four schizophrenic patients with depression presents with suicide ideation and therefore requires appropriate identification and management. As far as predisposing factors for the appearance of depression concerns, the existing data are inadequate and contradictory to extract safe conclusions and therefore further research is in line.

Key words: schizophrenia, depression, scales, psychometry, definition, epidemiology

S. Stamouli (page 68) - Full article (Greek)