Psychiatric disorders among adult deliberate self-harm patients and subsequent risk of dying by suicide, mental and behavioural disorders and other external causes

Introduction: Deliberate self-harm (DSH) treated in general hospital is a well-established risk factor for suicide and other cause mortality. However, few studies have used population data to investigate the differential impact of specific psychiatric disorders on the risk of subsequent suicide, by sex and age of the patient in the context of previous DSH episodes.

Method: All patients aged 18 and older treated for DSH in general hospitals during the period 2008-2018 were identified through national registers. Cox proportional hazards regression was used to ascertain the associated risk of death by suicide, mental and behavioural disorder and other external causes.

Results: The cohort consisted of 39 479 patients of which 878 died by suicide, 461 by mental and behavioural disorders and 1037 by other external causes. Overall, schizophrenia spectrum disorders, affective disorders and personality disorders increased the risk of suicide. Large gender and age differences were identified in the risk of suicide associated with personality disorders and affective disorders. Alcohol use disorders and dementia increased the risk of dying by mental and behavioural disorders and alcohol use disorders and other substance use disorders increased the risk of death by external causes.

Conclusion: Schizophrenia spectrum disorders, affective disorders and personality disorders increased the risk of suicide among DSH patients, but the effect varied by gender, age and history of previous DSH. Psychiatric evaluation of all DSH patients and treatment tailored to the patient’s specific needs is essential to reduce the risk of premature death.