OBJECTIVE: To investigate psychiatric outcomes after bariatric surgery, including suicide, self-harm, psychiatric service use and substance misuse.
METHOD: Retrospective study on a Danish nationwide register-based cohort of 22 451 patients followed for 1 029 736 person-years. Data were analysed utilizing single- and multi-event Cox regression with non-operated controls with obesity and mirror-image analyses with the operated patient serving as their own controls.
RESULTS: We showed an increased ratio of self-harm (hazard ratio [HR] 3.23, P < 0.001; incidence rate ratio [IRR] 1.71, P < 0.001), psychiatric service use (admissions IRR 1.52, P < 0.001; emergency room visits IRR 1.70, P < 0.001), psychiatric diagnosis (organic psychiatric disorders HR 1.78, P < 0.001; substance use HR 2.06, P < 0.001; mood disorders HR 2.66, P < 0.001; neurotic, stress-related and somatoform disorders HR 2.48, P < 0.001; behavioural syndromes HR 3.15, P < 0.001; disorders of personality HR 2.68, P < 0.001; behavioural and emotional disorders HR 6.43, P < 0.001), as well as substance misuse utilizing Cox regression as well as mirror-image analyses, as compared to non-operated. We did not find an increased suicide rate (HR 1.35, P = 0.658) among operated as compared to non-operated.
CONCLUSION: Our study shows that undergoing bariatric surgery is associated with increases in self-harm, psychiatric service use and occurrence of mental disorders.