In this large register-based study of individuals diagnosed with OCD in Sweden over four decades, we found that the disorder was strongly associated with suicidal behavior. The risk of dying by suicide was approximately ten times higher, and the risk of attempted suicide five times higher, than that of the general population. This risk remained substantial after adjusting for different groups of psychiatric comorbidities that are already known to be associated with suicide. In fact, 43% of the individuals from the OCD cohort who died by suicide did not have any other recorded psychiatric comorbidity. Thus, OCD is associated with an increased risk of death by suicide in its own right, a risk that was previously unappreciated. Our estimates place OCD at a comparable suicide risk with other mental disorders like schizophrenia,29 bipolar disorder30 and attention-deficit hyperactivity disorder,28 and at higher risk than posttraumatic stress disorder31 or alcohol use disorders.32
