STH MULTIDISCIPLINARY INTERNATIONAL

Conference of Biological Psychiatry

«Stress and Behavior»

Proceedings of the 9th International Multidisciplinary Conference «Stress and behavior» Saint-Petersburg, Russia, 16-19 May 2005 Editor: Allan V. Kalueff, PhD

6. GENERAL QUESTIONS:

PSYCHIATRY OF STRESS

SEASON-DEPENDENT MORBIDITY OF SCHIZOPHRENIA IN RURAL POPULATION

T. Nowakowski Psychiatric Health Service Center, Lodz, Poland

The purpose of the study was to assess the influence of the patient’s season-of-birth on morbidity of schizophrenia in rural population.

Method: The analysis involved examination of medical files of 547 patients treated for schizophrenia at Psychic Health Centre (Poradnia Zdrowia Psychicznego; PZP) providing psychiatric care solely for one rural commune (‘gmina’, administrative district) in the central Poland. Statistical methods included the analysis of temporal variation with Census II season-oriented correction method.

Results: The investigated population constituted .97% of all inhabitants of the commune. Analysis of the subsequent birthtime decades of the 20th century (starting from the 1920s) showed a gradual rise in the number of schizophrenia incidents (from 22 to 68) for patients born in the 1940s. People born in the 1950s showed maximal (193 incidents) occurrence of schizophrenia. Over the following years, the morbibity of schizophrenia tended to reduce rapidly down to 27 incidents in the 1980s. Within the population of patients subjected to analysis, morbidity was highest for people born in ‘winter’ months.

Conclusion: The first psychotic episode was shown to demonstrate earlier in life in people born in winter season than in those born at other times of the year. The rise in schizophrenia incidents in the 1950s requires further correlation with other (e.g., infection and immunological) factors. They may have a predictive value in developing schizophrenia via interference with certain processes in the central nervous system at the pre-natal or infancy period.

Psychopharmacol. Biol. Narcol. 2005. Vol. 5, N 2. P. 925

Psyhopharmacology & biological narcology

ISSN 1606—8181