Aggressive behaviour as a cause of psychiatric admission: A comparison between schizophrenic and affective disorder patients

One hundred and fifty-six subjects were randomly chosen from 1560 patients admitted to two psychiatric hospitals in Israel during 1991. The subjects' files were retrospectively studied to determine whether aggressive behaviour was the reason for psychiatric admission. We examined the relationship between aggressive behaviour, major psychiatric disorders (schizophrenia and affective disorder) and demographic variables (sex, age, family status and education). We also studied the monthly distribution of aggression throughout the year and the correlation to daily photoperiod duration. Forty-six per cent of the admissions related to aggressive behaviour. Schizophrenic patients were overly represented in the aggressive group. The monthly distribution of aggressive behaviour differed between schizophrenic and affective disorder patients. While the latter showed a seasonal pattern of aggressiveness, with a statistically significant peak during spring and winter, schizophrenic aggressive patients were distributed equally throughout the year. No statistically significant correlation was found between the incidence of aggression and the photoperiod duration.