Predictors of Later Schizophrenia and Affective Psychosis Among Attendees at a Child Psychiatry Department

Longitudinal research shows that many mental disorders do notarise de novo in adult life but have roots further back inchildhood (Rutter, 1984; Caspi et al., 1996). Schizophreniais associated with significant impairments in childhood, but little work has yet been carried out on affective psychosis.Longitudinal prospective studies are an ideal way to studychildhood precursors of

adult psychotic illness, but the lengthof the follow-up period and the large sample sizes requiredmake this a prohibitively costly exercise. One approach is to use existing general population birth cohorts (Done et al., 1994; Jones et al., 1994), but although such samples have theadvantage of an epidemiological design, they usually have fewdata on psychological symptoms in childhood, and have low statisticalpower to study relatively rare disorders such as schizophrenia.Data collected from attendees at child psychiatric clinics can overcome both of these difficulties. We have utilized a valuableresource of standardized psychological data collected overmany years from a large child psychiatric service to examinepredictors of later psychosis.