Erlangsen, A., Lind, B. D., Stuart, E. A., Qin, P., Stenager, E., Larsen, K. J., ... & Nordentoft, M. (2014). Short-term and long-term effects of psychosocial therapy for people after deliberate self-harm: A register-based, nationwide multicentre study using propensity score matching. The Lancet Psychiatry. Early Online Publication: doi:10.1016/S2215-0366(14)00083-2.
Between 9 million and 35 million suicide attempts occur yearly in the world, and suicide accounts for over 800,000 deaths every year worldwide. Suicide attempts are associated with future attempts and with mortality. Within the first year, 16% of people attempt suicide again. Despite the occurrence of suicide attempts and its effects, there has been inconclusive evidence of the effectiveness of interventions to reduce future attempts and death. That is why this Danish nationwide study by Erlangsen is so important. Another impressive aspect of this study is its size and scope. Since 1992, psychological therapies have been offered to people at risk of suicide in specialized clinics throughout Denmark. The aim of Erlangsen and colleagues’ study was to assess if those who received these psychological interventions had a reduced risk of suicidal behavior and mortality compared to people who did not receive the interventions. The authors collected data from 1992 to 2010 from Danish national health registries. This procedure was possible in Denmark because the health system is nationally coordinated and each individual has a traceable national health ID. In order to be included in the study, those who were offered specialized psychological interventions had to receive at least one session of treatment. Therapy included cognitive behavioral therapy, problem solving therapy, dialectical behavior therapy, psychodynamic therapy, systemic therapy and others. The interventions consisted of up to 8 to 10 individual outpatient sessions. The comparison group received “standard care” that consisted of admission to hospital, referral to a general practitioner, or discharge with no referral. The primary outcomes were: repeated self-harm, death by suicide, and death by any other cause. Of the people receiving psychotherapy, 5,678 had useable data. The “standard care” sample was much larger and consisted of 58,281 individuals who were matched to the psychological intervention group on many variables including sex, age, education, antidepressant medications, and psychiatric diagnosis. For those receiving psychotherapy, the rate of repeated suicide attempts in the first year was 6.7% and 15.5% at 10 years. For those receiving standard care, rate of repeated suicide attempts in the first year was 9.0% and 18.4% at 10 years. The odds of another suicide attempt one year post treatment was 73% lower among those receiving psychotherapy. Death by any other cause at the 10 year mark was also significantly lower in the psychological therapy group (5.3%) versus the no-therapy group (7.9%). The authors estimated that over the 20 year span of their data, psychological therapy: prevented repeated suicide attempts in 145 people, prevented deaths by any other cause in 153 people, and prevented 30 suicide deaths. Psychosocial interventions were associated with fewer repeated suicide attempts in women but not in men, and adolescents and young adults benefited most from psychological therapies.
This is the largest long term follow up study ever of psychological interventions after a suicide attempt. Psychotherapy was associated with reduced risk of self-harm and mortality in the short and long term. This was especially true for women and in adolescents and young adults. Those receiving psychotherapy might have been a select group resulting in biased results. However, the extensive matching of the psychotherapy group to the no-therapy control group reduced the likelihood that factors other than psychotherapy influenced the findings. The study indicates strong support for providing psychological interventions to people at risk of suicide.