Predictors of psychosis: a 50-year follow-up of the Lundby population.

Behavioural and neuropsychological vulnerability have been associated with an increased risk of psychosis. We investigated whether certain clusters of premorbid behavioural and personality-related signs and symptoms were predictors of nonaffective and/or affective psychosis and schizophrenia, respectively, in a 50-year follow-up of an unselected general community population. Total population cohorts from the same catchment area in 1947 (n = 2,503) and 1957 (n = 3,215) that had been rated for behavioural items and enduring symptoms were followed up to 1997 regarding first-incidence of DSM-IV nonaffective and/or affective psychosis. Attrition was 1-6%. The influence of the background factors, aggregated in dichotomous variables (predictors), on time to occurrence of nonaffective and/or affective psychosis was assessed by means of Cox regression models. In multivariate models the predictors nervous-tense, blunt-deteriorated, paranoid-schizotypal and tired-distracted were significantly associated with subsequent nonaffective and/or affective psychosis. In simple models, down-semidepressed, sensitive-frail and easily hurt were significantly associated with development of psychosis. When schizophrenia was analysed separately nervous-tense remained significant in the multivariate model, although blunt-deteriorated, paranoid-schizotypal and tired-distracted did not; and abnormal-antisocial reached significance. To conclude, we found some evidence for anxiety-proneness, affective/cognitive blunting, poor concentration, personality cluster-A like traits and interpersonal sensitivity to be associated with general psychosis vulnerability.