Impairment in both psychosocial functioning and neurocognition (NC) performance is present in bipolar disorder (BD) yet the role of sex differences in these deficits remains unclear. The present systematic review and meta-analysis examined whether males and females with BD demonstrate differences in psychosocial functioning and NC performance.

The Cochrane Library, EMBASE, PsycINFO, PubMed, Scopus, and Web of Science databases were systematically searched from inception until November 20, 2023.

Twenty studies published between 2005 and 2023 with a total sample size of 2286 patients with BD were included. A random effects meta-analysis revealed a statistically significant result with a small effect (SMD = 0.313) for sex differences in verbal learning and memory as well as visual learning and memory (SMD = 0.263). Females outperformed males in both domains. No significant sex differences were observed for any other NC outcome or psychosocial functioning. High heterogeneity and differences in assessment scales used should be considered when interpreting these findings, given their potential impact on results.

Future research should adopt a more homogenous, standardized approach using longitudinal designs to gain a clearer insight into sex differences in this population. This approach so may increase the use of preventative therapeutic options to address the difficult clinical challenge of reaching cognitive and functional recovery.

A recent genome-wide association study (GWAS) identified 12 independent loci significantly associated with attention-deficit/hyperactivity disorder (ADHD). Polygenic risk scores (PRS), derived from the GWAS, can be used to assess genetic overlap between ADHD and other traits. Using ADHD samples from several international sites, we derived PRS for ADHD from the recent GWAS to test whether genetic variants that contribute to ADHD also influence two cognitive functions that show strong association with ADHD: attention regulation and response inhibition, captured by reaction time variability (RTV) and commission errors (CE).

The discovery GWAS included 19 099 ADHD cases and 34 194 control participants. The combined target sample included 845 people with ADHD (age: 8–40 years). RTV and CE were available from reaction time and response inhibition tasks. ADHD PRS were calculated from the GWAS using a leave-one-study-out approach. Regression analyses were run to investigate whether ADHD PRS were associated with CE and RTV. Results across sites were combined via random effect meta-analyses.

When combining the studies in meta-analyses, results were significant for RTV (R2 = 0.011, β = 0.088, p = 0.02) but not for CE (R2 = 0.011, β = 0.013, p = 0.732). No significant association was found between ADHD PRS and RTV or CE in any sample individually (p > 0.10).

We detected a significant association between PRS for ADHD and RTV (but not CE) in individuals with ADHD, suggesting that common genetic risk variants for ADHD influence attention regulation.