The antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction and speech problems.

OBJECTIVE: Adults with non-affective psychosis show subtle deviations in a range of developmental trajectories as children and adolescents.
METHOD: Based on a birth-cohort (n = 3801), we examined the Peabody Picture Vocabulary Test (PPTV) at age 5, and Raven's Standard Progressive Matrices (RSPM) and Wide Range Achievement Test reading scale (WRAT-R) at age 14. Items related to speech problems and attentional dysfunction were available from maternal- or self-report. At age 21, we identified 60 cohort members who were screen-positive for non-affective psychosis (SP-NAP).
RESULTS: Impaired performance on the PPVT and RSPM (but not WRAT-R) predicted SP-NAP for males only. Male cohort members in the highest quartile for attentional dysfunction at ages 5 and 14 were about 5-8 times more likely to develop SP-NAP. SP-NAP in males was significantly associated with speech problems at age 14.
CONCLUSION: Males who develop non-affective psychoses have subtle impairments in cognitive capacity prior to the development of their psychotic disorder.