Intentional self-harm and death by suicide in body dysmorphic disorder:A nationwide cohort study

Objectives Body dysmorphic disorder (BDD) is thought to be associated with considerable suicide risk. This nationwide cohort study quantified the risks of intentional self-harm – including non-suicidal self-injuries and suicide attempts – and death by suicide in BDD. Methods Individuals with a validated ICD-10 diagnosis of BDD in the Swedish National Patient Register, registered between January 1, 1997 and December 31, 2020, were matched with 10 unexposed individuals from the general population on birth year, sex, and county of residence. Conditional Poisson regression models estimated incidence rate ratios (IRR) and 95% confidence intervals (CIs) for intentional self-harm and stratified Cox proportional hazards models estimated hazard ratios (HRs) and 95% CIs for death by suicide. Models adjusted for sociodemographic variables and lifetime psychiatric comorbidities. Results Among 2,833 individuals with BDD and 28,330 unexposed matched individuals, 466 (16.45%) and 1,071 (3.78%) had at least one record of intentional self-harm during the study period, respectively (IRR=3.37; 95% CI, 3.02-3.76). In the BDD cohort, about two thirds (n=314; 67%) had their first recorded self-harm event before their first BDD diagnosis. A total of 17 (0.60%) individuals with BDD and 27 (0.10%) unexposed individuals died by suicide (HR=3.47; 95% CI, 1.76-6.85). All results remained robust to additional adjustment for lifetime psychiatric comorbidities. A higher proportion of individuals with BDD who died by suicide had at least one previous record of intentional self-harm, compared to unexposed individuals (52.94% vs. 22.22%; p=0.0363). Conclusions BDD was associated with a three-fold increased risk of intentional self-harm and death by suicide.