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

Abstract

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

Examining the Psychosis Continuum

“…Deficits across a range of cognitive skills have increasingly been recognized as a core feature of psychotic illness, with cognitive deficits manifesting in schizophrenia, schizotypal personality disorder, and schizophrenia patients’ unaffected first degree relatives [53–55]. However, despite large-scale longitudinal birth-cohort data implicating deficits in general cognitive function [g] at ages 8, 11, and 15 in the manifestation of later subclinical psychotic symptoms in middle age [56], cross-sectional studies investigating the role of subclinical psychosis in neurocognitive performance have produced inconsistent results. While some studies have linked subclinical psychosis to deficits in cognitive function including visual memory and visuoconstructive performance [57], verbal fluency [58–60], working memory [61], selective and sustained attention [60, 62–65], cognitive set shifting [66], and capacity for abstract reasoning [66], other studies have found no significant links between subclinical psychosis and performance deficits in these cognitive areas [67–73].…”

Cognitive Deficits in Psychotic Disorders: A Lifespan Perspective

“…In one of the first studies to directly ask whether cognition is intact in individuals who endorse psychotic-like experiences, Barnett and colleagues (2012) utilized a population-based sample in Great Britain of 2918 participants (Barnett et al 2012). Of those, 22% reported psychotic-like experiences at age 53, and those who reported psychotic-like experiences had poorer childhood cognitive test scores at ages 8 and 15.…”

Cingulo-opercular Network Efficiency Mediates the Association Between Psychotic-like Experiences and Cognitive Ability in the General Population

“…However research suggests that approximately 8–20% of clinically healthy individuals endorse occasional psychotic-like experiences (PLEs) that may or may not impact functioning (1, 2). As such, psychotic experiences occur on a continuum, with a subset of the general population experiencing PLEs in the absence of a diagnosable disorder, while another subset (e.g., individuals with schizophrenia) experience frequent and debilitating psychosis in conjunction with other psychiatric symptoms (3).…”

“…This hypothesis was based on previous literature showing that greater PLEs (2, 7) and lower network efficiency (32) are associated with lower cognitive ability – associations we hoped to replicate and extend to the general population, in order to test the psychosis continuum model. Additionally, we hypothesized that efficiency of these networks would mediate the relationship between psychosis and cognitive ability, suggesting a shared mechanism between these two phenotypes.…”