INFLUENCE OF SEASON ON MANIFESTATION OF SCHIZOPHRENIC SUBTYPES

In the modern classification systems ICD-10 and DSM-III-R, the term se asonality has been given a separate significance in the diagnostic cat egorization of affective disorders. Its definition is oriented not mer ely to the increased seasonal prevalence in the autumn and winter mont hs, but also to symptoms that do not occur in nonseasonal attacks. To date, research work on seasonality in schizophrenia has concentrated o n birth seasonality, while no results based on large populations of pa tients have yet become available on the manifestation seasonality of s chizophrenic subtypes. Within the framework of a retrospective study c arried out in the period between 1983 and 1995, involving 2,119 patien ts suffering from recurrent attacks of schizophrenia, seasonal manifes tations were recorded in accordance with the criteria defined in DSM-I II-R. It was found that the two subtypes of paranoid hallucinatory and schizoaffective psychoses met the criterion of seasonality significan tly more frequently than did the subtypes disorganized and catatonic d isorders. In addition, seasonal courses within the groups just mention ed clearly differed from the nonseasonal forms in terms of their sympt omatology.