FIRST-ONSET SCHIZOPHRENIA IN THE COMMUNITY - RELATIONSHIP OF URBANIZATION WITH ONSET, EARLY MANIFESTATIONS AND TYPOLOGY

As part of a World Health Organization collaborative study in 12 centr es in developing and developed countries within defined urban and rura l catchment areas with populations of 348786 and 103865, respectively, a total of 155 and 54 cases of first-onset schizophrenia, respectivel y, were identified over a 24-month period by a comprehensive and activ e recruitment of all cases. Approximately 50% of the subjects in both cohorts were in the age range of 15-24 years. There was a preponderanc e of males in the younger age group and of females in the older age gr oup. The majority of cases had no family history and had shown good ad justment in childhood and adolescence. The onset was much more frequen tly acute and much less often insidious in our samples and (more so in the rural cohort), compared to the figure for all developed countries ' sites. With regard to early manifestations of the disorder, there wa s a much higher incidence of loss of interest in appearance and cleanl iness, being irritable and angry without reason, and loss of appetite, sleep or interest in sex in both of our samples, and of being excited or overactive for days or weeks in our rural cohort than in the devel oped countries' centres as a whole. On the other hand, claiming imposs ible things, behaving as if hearing voices and feeling persecuted, har med or bewitched were much less frequent in our rural cohort than in t he urban cohort or the developed countries' centres as a whole. With r egard to the clinical diagnosis of schizophrenia, paranoid, hebephreni c/disorganized and residual types were under-represented in our sample s (more so in the rural sample), and catatonic type and acute schizoph renic episode were over-represented compared to the developed countrie s' centres. Moreover, the proportion of subjects of CATEGO class S+ wa s lower in our samples. With regard to onset, early manifestations and clinical subtypes of schizophrenia, our rural cohort deviated most fr om developed countries' centres as a whole, with our urban sample fall ing in between, thus indicating the role of socio-cultural factors in general, and urbanization in particular, in these variables in schizop hrenia.