American Journal of Preventive Medicine
Promising Strategies for Advancement in Knowledge of Suicide Risk Factors and Prevention
Introduction
Suicide is an important cause of death throughout the world.1 Suicide rates in the U.S. have increased rather than decreased in the last decade.2 There is an urgent need for research that rapidly advances knowledge and has rapid uptake by policymakers and clinicians to reduce suicide deaths.
One of the major challenges in advancing knowledge around suicide prevention is that deaths by suicide are relatively infrequent events. Although the gold standard test of an intervention is an RCT, conducting RCTs that are powered for detecting impact on suicides are expensive, difficult to coordinate, and require long periods of follow-up.3 Here, we discuss three key research pathways (analysis of existing data sets that include suicide variables, networks and consortia focused on suicide prevention, and researchers working with policymakers to address important questions related to suicide) that we believe can advance the field of suicide prevention in a manner that will reduce suicides over the next 10 years. To guide the current discussion, we list the well-established suicide risk factors4 and prevention strategies at the individual, family, and community levels (Table 1) and describe the limitations of the current knowledge in these areas.
Suicide is, fortunately, a relatively rare event. Unfortunately, this makes it hard to study for a variety of reasons.4 First, empirical data on optimal screening and prediction tools for suicide are lacking.5 Many suicide risk assessment tools (e.g., SAD PERSONS scale) have good sensitivity but poor positive predictive value in their ability to forecast future suicide attempts.5, 6
Second, there is a lack of understanding of suicide risk in vulnerable groups (e.g., military personnel, ethnic minorities, socially deprived individuals). For example, depending on the group studied, social markers such as income and marital status have been shown to be both suicide risk and protective factors.7, 8
Third, with the recent increase in use of social media, information is lacking on the impact of exposure to suicide in social media on suicide contagion. Fourth, although there has been an increase in prevalence of non-suicidal self-injury,9 the longitudinal course and risk for death by suicide among people with non-suicidal self-injury remains unknown. Fifth, most epidemiologic studies of suicidal ideation and attempts have been cross-sectional, may be affected by recall bias, and are not generalizable to death by suicide.
Although a wide range of suicide prevention strategies are suggested in guidelines worldwide (Table 1), it is important to underscore that most of the suicide prevention strategies, with the exception of means restriction policies,10 training of physicians in treating depression,11 and postcards after hospitalization for suicide attempts,12 lack strong empirical evidence for reducing suicidal behavior. There is, therefore, an urgent need to rigorously test promising suicide prevention strategies.
Owing to the low base rate phenomenon of suicide, extremely large sample sizes (thousands of people) often followed over relatively long periods of time are required to test whether interventions are effective. The most-cited studies in the field of suicide prevention to date are quasi-experimental designs in high-risk adult groups (e.g., Air Force personnel,13 regions of Hungary14) where improving/increasing gatekeeper training for suicide and treatment of depression by primary care physicians reduced suicide rates.
Furthermore, large-scale clinical trials for mental disorders often exclude people with a high risk of suicidal behavior. Thus, there is little information available from RCTs regarding effective interventions in high-risk adults. Even less data are available for optimal methods of intervention in culturally diverse groups.15 Finally, given the complex multifactorial and heterogeneous etiology of suicide, large-scale public health interventions may be expensive and typically have small effect sizes.16 In the context of limited funding for research, investigators often face significant obstacles in designing fundable studies.
Section snippets
Suggested Research Pathways
In order to advance knowledge of suicide risk factors and evaluate suicide prevention strategies, the following three main research pathways are suggested (Table 2).
Acknowledgments
Publication of this article was supported by the Centers for Disease Control and Prevention, the National Institutes of Health Office of Behavioral and Social Sciences, and the National Institutes of Health Office of Disease Prevention. This support was provided as part of the National Institute of Mental Health-staffed Research Prioritization Task Force of the National Action Alliance for Suicide Prevention.
Preparation of this article was supported by a Canadian Institutes of Health Research
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