In schizophrenia, the first contact with mental health services is frequently preceded by a lengthy, mostly untreated prephase. We have retrospectively studied a population-based sample of 232 first episodes of broadly defined schizophrenia, using a semi-structured interview (interview for the retrospective assessment of the onset of schizophrenia, IRAOS) from first admission to the first sign of the disorder. A representative subsample (n=115) was followed prospectively over six occasions until five years after first admission. Three-quarters of the cases began with a prodromal phase, lasting five years on average. This was followed by a psychotic prephase of about one year with an exponential increase in all symptoms until the climax of the first episode.

The ten most frequent initial signs were predominantly negative and affective symptoms, including indicators of functional impairment. Depressive symptoms following the first psychotic symptom showed a significant correlation with the score of positive symptoms in the first psychotic episode. A lack of early depressive symptoms is a significant prediction of affective flattening and a weaker prediction of anhedonia over the five years after first admission.

Social disability occurred as early as two to four years before first admission. Compared with age-and sex-matched controls from the general population, the patients at onset of illness did not differ significantly from their healthy peers in terms of social status, but already showed considerable social deficits. These emerged in the prodromal phase, long before first admission. In early-onset cases, the expected social ascent was impeded, whereas in late-onset cases there was considerable downward drift from a higher status at onset.