RESUMEN
This study aimed 1) at determining the seasonal pattern of the first onset and 2) at examining different demographic and clinical factors by the seasonality of first onset, for shizophrenia, mood disorder and subtypes of each diagnosis. Finally, the 52 subjects with paranoid schizophrenia were selected from all patients who fulfilled DSM-IV criteria far schizophrenia who had been admitted to the National Seoul Mental Hospital from March 1994 to February 1995. And the 44 subjects with bipolar I disorder were selected from all patients who fulfilled DSM-IV criteria for mood disorder who had been admitted to the hospital from March 1994 to February 1996. This study was done by reviewing the hospital records about season of the first outset, demographic factors(sex, age, occupation, educated period, religion, marital status, residence and socioeconomic status) and clinical factors(age at the first onset, duration of illness, family history, length of admission, frequency of admission and treatment result). The seasonal pattern of the first onset and the different demographic and clinical factors by the season of the first onset in paranoid shizophrenia and I disorder were analyzed. The results were as follows: 1) There was no significant seasonal variation of the first onset for paranoid schizophrenia. 2) There was a significant seasonal variation of the first onset with a maximum in spring for bipolar I disorder. 3) There was no significant seasonal variation of the first onset in case of bipolar I disorder that began with the manic episode. 4) There was nonsignificant seasonal tendency to peak in spring/summer in the case of the first manic episode for bipolar I disorder. 5) There were no significant differences in demographic and clinical factors by the season of the first onset for paranoid schizophrenia and bipolar I disorder.