Psychiatric Disorders Before and After Inflammatory Bowel Disease Diagnosis: A Nationwide Cohort Study in Sweden 2007 to 2023.

BACKGROUND & AIMS: Evidence suggests that patients with inflammatory bowel disease are at higher risk of psychiatric disorders, yet temporal pattern of risk elevation before/after inflammatory bowel disease diagnosis and role of familial factors remain unclear.

METHODS

Swedish patients with inflammatory bowel disease diagnosed between 2007 and 2023 were compared with reference individuals in a matched population-based cohort and compared with inflammatory bowel disease-free full siblings in a sibling-controlled cohort. Primary outcome was any psychiatric disorder, whereas secondary outcomes included psychotic disorders, mood disorders, anxiety disorders, eating disorders, substance misuse, personality disorders, attention-deficit/hyperactivity disorder, and autism spectrum disorders. We estimated temporal patterns of hazard ratios from 5 years before to 10 years after inflammatory bowel disease diagnosis by using flexible parametric survival models.

RESULTS

The study included 43,862 patients with inflammatory bowel disease (mean age at diagnosis, 41.6 years; 47.3% female) and 178,821 reference individuals. The hazard ratio of any psychiatric disorder started to increase from 2 to 3 years before inflammatory bowel disease diagnosis (eg, hazard ratio, 1.15; 95% confidence interval, 1.09-1.21 at -2 years), peaked immediately after inflammatory bowel disease diagnosis (hazard ratio, 1.50; 95% confidence interval, 1.41-1.59 at 0.5 year), and decreased rapidly thereafter but remained increased even at 10 years after diagnosis (hazard ratio, 1.19; 95% confidence interval, 1.13-1.24). The increased hazard ratio was mainly driven by major depressive disorder, anxiety disorders, and substance misuse. No increase was observed for psychotic disorders, personality disorders, and attention-deficit/hyperactivity disorder, although patients with inflammatory bowel disease were more likely to have autism spectrum disorders shortly after diagnosis and eating disorders from ≥5 years onwards. Similar temporal hazard ratio patterns were observed across all subtypes of inflammatory bowel disease: Crohn's disease, ulcerative colitis, and inflammatory bowel disease-unclassified. Similar risk increases for psychiatric disorders were observed in the sibling-controlled cohort.

CONCLUSIONS

Patients with inflammatory bowel disease were at an increased risk of several psychiatric disorders from 2 to 3 years before diagnosis through up to 10 years after, and this risk increase cannot be fully explained by shared familial factors.