Exploring the causal relationship between bipolar disorders and sensory, motor, and behavioral disorders: A bidirectional Mendelian randomization analysis.

This genetic study found connections between bipolar disorder and other conditions. Children with bipolar disorder may have higher genetic risk for skin itching, nerve problems, movement disorders, eating disorders, and autism. The study also found that some skin conditions may increase risk for bipolar disorder, while certain movement disorders may be protective. These findings suggest these conditions share some genetic causes and families should be aware of potential connections.

This bidirectional Mendelian randomization study examined genetic causal relationships between bipolar disorder and sensory, motor, and behavioral conditions using genome-wide association study data. The analysis found that bipolar disorder increases genetic susceptibility to pruritus (29% increased risk), small fiber neuropathy (64% increased risk), hyperkinetic disorders (102% increased risk), anorexia nervosa (19% increased risk), and autism spectrum disorder (10% increased risk). Conversely, pruritus and psoriasis were identified as genetic risk factors for bipolar disorder, while motor disorders showed a protective effect. These findings suggest shared genetic mechanisms and highlight the importance of integrated clinical management and early screening across these interconnected conditions.

Findings support integrated screening approaches for children with bipolar disorder or autism spectrum disorder. Clinicians should consider comorbidity patterns when assessing developmental and behavioral concerns. Early identification strategies may benefit from considering these genetic relationships, particularly in families with multiple affected conditions.

Study relies on genetic associations which may not translate directly to clinical causation. Sample sizes for individual conditions not reported. Cross-population generalizability unclear. Cannot establish timing of relationships or account for environmental factors that may modify genetic risk.

The interrelationships between bipolar disorder (BD) and sensory, motor, and behavioral disorders are intricate and not well defined. While observational studies indicate potential associations, causal relationships have not been established. This study applies bidirectional Mendelian randomization (MR) analysis to examine potential causal links between BD and these disorders. Bidirectional MR analysis uses summary-level data from genome-wide association studies (GWAS).

Genetic instruments are selected according to stringent significance thresholds and linkage disequilibrium (LD) criteria. The primary analytical approaches include inverse-variance weighted (IVW) MR and MR-Egger regression. Instrument strength is assessed using F-statistics. Significant bidirectional associations are identified.

BD is associated with increased genetic susceptibility to pruritus (OR = 1.29, 95% CI: 1.06-1.57), small fiber neuropathy (OR = 1.64, 95% CI: 1.03-2.61), hyperkinetic disorders (OR = 2.02, 95% CI: 1.26-3.23), anorexia nervosa (OR = 1.19, 95% CI: 1.01-1.40), and autism spectrum disorder (OR = 1.10, 95% CI: 1.01-1.20). Conversely, pruritus and psoriasis are identified as significant genetic risk factors for BD (pruritus: OR = 1.04, 95% CI: 1.01-1.08; psoriasis: OR = 9.97, 95% CI: 1.85-53.67). Motor disorders are associated with a protective effect against BD (OR = 0.88, 95% CI: 0.80-0.96). This study demonstrates significant bidirectional causal associations between BD and sensory, motor, and behavioral disorders, underscoring the importance of early screening and integrated clinical management.

Shared genetic and neurobiological mechanisms may inform the development of targeted interventions and therapeutic strategies.