Psychiatric Comorbidity in Hidradenitis Suppurativa-A Large-Scale Retrospective Cohort Study

Background/Objectives: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with psychiatric burden, but longitudinal data on incident psychiatric outcomes remain limited. This study aimed to evaluate incident psychiatric disorders in adults with HS compared with matched non-HS controls and to assess sex-specific risk. Methods: We conducted a retrospective propensity score-matched cohort study using the TriNetX Global Collaborative Network. Adults with at least two HS diagnoses and no prior psychiatric diagnosis were compared with non-HS controls with repeated general health examination encounters and no psychiatric history. Time-to-event analyses estimated hazard ratios (HRs) with 95% confidence intervals (CIs). Sensitivity analyses used a 30-day lag and restriction to the most recent 5-year period. Results: After matching, 37,964 pairs were retained for the primary individual-outcome analysis. Median follow-up was shorter in the HS cohort than in matched controls (844 vs. 1505 days). HS was associated with increased risk of any psychiatric disorder (12.3% vs. 5.8%; HR 3.17, 95% CI 3.01-3.34) and severe psychiatric illness (0.6% vs. 0.1%; HR 6.70, 95% CI 4.77-9.41). Elevated risks were observed for bipolar/manic disorders, personality disorders, substance use disorders, psychotic disorders, suicidal ideation, depression, eating disorders, anxiety, and insomnia/parasomnia. Women had higher hazards of depression and anxiety, whereas men had higher hazards of substance use disorders; insomnia/parasomnia showed a nominal association with higher hazard in men. Conclusions: In this observational EHR-based study, HS was associated with broad incident psychiatric morbidity. These findings support consideration of proactive mental health assessment and integrated dermatologic-psychiatric care in patients with HS.