Cognitive functioning in people with psychotic experiences: a systematic review and meta-analysis study

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Previous research indicated a link between psychotic experiences (PEs) and cognitive impairment, but findings have been mixed.
• The precise nature and extent of cognitive deficits associated with PEs require further clarification.

Purpose of the Study:

• To systematically review and quantitatively synthesize cognitive functioning in individuals with and without PEs.
• To explore potential moderators of cognitive deficits in PEs, including age, sex, and assessment methodology.

Main Methods:

• A meta-analysis of 27 studies comparing cognitive functioning in individuals with versus without PEs (n=82,561).
• Inclusion of 6 additional studies for high-level versus low-level PEs comparison (n=8062).
• Random-effects models were used to calculate pooled effect sizes (Hedges' g), with subgroup analyses and meta-regression.

Main Results:

• Individuals with PEs showed significantly worse performance in general cognition (g=-0.10), verbal fluency (g=-0.05), visual memory (g=-0.21), and working memory (g=-0.16).
• General cognition deficits were associated with younger age, male sex, and prior PE assessment.
• Working memory deficits were linked to concurrent cognitive and PE assessment; no significant differences were found between high-level and low-level PEs.

Conclusions:

• PEs are associated with milder and more circumscribed cognitive impairments compared to established psychotic disorders.
• Cognitive deficits in PEs are influenced by factors such as age, sex, and assessment timing.
• Further research is needed to differentiate cognitive trajectories in transient versus persistent PEs.