Risk of Suicide in Patients With Bipolar Disorder Having Comorbid Chronic Pain Disorders: Insights From the Nationwide Inpatient Sample Data From 2016 to 2018

Bipolar disorders (BDs) are associated with significant risk of suicide. BD patients (age ≥18 years) admitted to the hospital were identified from the National Inpatient Sample dataset. Based on the secondary diagnosis of chronic pain disorder (CPD), patients were stratified into two groups (1) BD with CPD (BD + CPD) and (2) BD without CPD (BD - CPD). Groups were matched (1:1) for the type of BD and compared for baseline characteristics and suicidal ideation/attempt (SI/SA). Compared with BD - CPD, most patients in the BD + CPD group were older (mean age, 47.6 vs. 40.4 years), female (58.4% vs. 55.2%), and white (77.2% vs. 66.7%). After adjusting for covariates, compared with the BD - CPD group, the BD + CPD group had 21% more risk of SI/SA (odds ratio, 1.21, p < 0.001). CPD is independently associated with the increased risk of suicide among patients with BD. Thus, comorbid CPD among patients admitted for BD can be an essential risk factor for suicide.