Suicide risk after nonfatal self-harm: A national cohort study, 2000-2008
Runeson, B., Haglund, A., Lichtenstein, P., & Tidemalm, D.
Objective: To study the short-term risk of suicide after nonfatal deliberate self harm and its association with coexisting mental disorders and with the method of self-harm used.
Method: We used linked Swedish national registers to design a cohort study with 34,219 individuals (59% females) who were admitted to hospital in 2000-2005 after deliberate self-harm (ICD-10-defined). They were followed for 3-9 years.
The studied outcome was completed suicide; Cox regression models yielded hazard ratios (HRs) for suicide risk. Temporal patterns were plotted with KaplanMeier survival curves, calculated separately for each mental disorder and for the
method used at the previous self-harm event.
Results: 1,182 subjects committed suicide during follow-up (670 males and 512 females). Coexisting bipolar disorder (in males, adjusted HR = 6.3; 95% confidence interval [CI], 3.8-10.3; in females, adjusted HR = 5.8; 95% CI, 3.4-9.7) and
nonorganic psychotic disorder (in males, adjusted HR = 5.1; 95% CI, 3.5-7.4; in females, adjusted HR = 4.6; 95% CI, 2.8-7.7) implied the highest risk of suicide after previous self-harm. Hanging as index self-harm method was a strong predictor of later suicide in both males (adjusted HR = 5.3; 95% CI, 4.0-7.0) and females (adjusted HR = 4.5; 95% CI, 2.5-8.1). Of those with bipolar disorder who used a method other than poisoning at the index event, 20.4% had already committed suicide after 3-9 years.
Conclusion: Individuals with severe mental disorders (affective and psychotic disorders) have a poor prognosis in the first years after hospital admission due to self-harm. The risk of subsequent suicide is higher after attempts by hanging and other self-injury methods (vs self-poisoning). Aftercare for those with a self-harm episode should focus on treatment of the mental disorder present at the time of the episode.