Childhood cognitive function and adult psychopathology:associations with psychotic and non-psychotic symptoms in the generalpopulation

BackgroundLower cognitive ability in childhood is associated with increased risk offuture schizophrenia, but its relationship with adult psychotic-likeexperiences and other psychopathology is less understood.AimsTo investigate whether this childhood risk factor is shared with adultsubclinical psychiatric phenotypes including psychotic-like experiencesand general psychiatric morbidity.MethodA population-based sample of participants born in Great Britain during 1week in March 1946 was contacted up to 20 times between ages 6 weeks and53 years. Cognition was assessed at ages 8, 11 and 15 years using acomposite of age-appropriate verbal and non-verbal cognitive tests. Atage 53 years, psychotic-like experiences were self-reported by 2918participants using four items from the Psychosis Screening Questionnaireand general psychiatric morbidity was assessed using the scaled versionof the General Health Questionnaire (GHQ-28).ResultsPsychotic-like experiences were reported by 22% of participants, and werehighly comorbid with other psychopathology. Their presence in adults wassignificantly associated with poorer childhood cognitive test scores atages 8 and 15 years, and marginally so at age 11 years. In contrast, highGHQ scores were not associated with poorer childhood cognition afteradjustment for the presence of psychotic-like experiences.ConclusionsPsychotic and non-psychotic psychopathologic symptoms are highly comorbidin the general population. Lower childhood cognitive ability is a riskfactor for psychotic-like experiences in mid-life; these phenomena may beone end of a continuum of phenotypic expression driven by variation inearly neurodevelopment.