The Hampstead Schizophrenia Survey 1991. I: Prevalence and service use comparisons in an inner London health authority, 1986-1991.

BACKGROUND: A point prevalence study of schizophrenia was carried out in 1986 in the former Hampstead Health District using a key informant method to identify cases. The point prevalence of broadly defined schizophrenia was 4.7 per 1000. METHOD: A repeat census of people with schizophrenia, using the same method, was carried out in 1991 and the point prevalence calculated. The accuracy of the census method was estimated. Contact with services, social and occupational activity, and medication usage in the 1986 and 1991 samples were compared. RESULTS: The point prevalence rate of broadly defined schizophrenia in 1991 was 5.1 per 1000. The results of both censuses showed we underestimated the number of individuals with DSM-III-R positive schizophrenia by about 14%. The level of contact with specialist services was greater in 1991 than 1986. Patients in 1991 were discharged on higher doses of medication, and their most recent admission was more likely to be due to non-compliance, than the 1986 group. CONCLUSION: The point prevalence confirmed the high rate reported in 1986. The accuracy of the census was within acceptable limits for service planning. Contact with specialist services increased between 1986 and 1991.

The Hampstead Schizophrenia Survey 1991. II: Incidence and migration in inner London.

BACKGROUND: The previous paper reports a high prevalence of schizophrenia (broad definition) in an inner London area. In this paper we test hypotheses for this finding and examine the characteristics of people with schizophrenia who move frequently. METHOD: People with schizophrenia in the Hampstead area were identified by key informant methodology, at two censuses five years apart. This allowed identification of incident cases during these five years and identification of people who had moved into and out of the area. RESULTS: The incidence of DSM-III-R schizophrenia in Hampstead between 1986 and 1991 was at least 0.21 per 1000 of the population aged 15 to 54. There was a significant movement of people with schizophrenia to this inner London area from outer London between 1986 and 1991. People with schizophrenia who were relatively mobile were significantly more likely to be male, to suffer with prominent hallucinations, and to have no contact with a GP. CONCLUSIONS: The high prevalence of broad schizophrenia in this inner London area is, in part, due to geographical drift. A significant excess of the people with schizophrenia who move frequently are men with positive symptoms.