Written By Mia Ballard

September 2, 2021  

Fox, K. R., Huang, X., Guzmán, E. M., Funsch, K. M., Cha, C. B., Ribeiro, J. D., & Franklin, J. C. (2020). Interventions for suicide and self-injury: A meta-analysis of randomized controlled trials across nearly 50 years of research. Psychological Bulletin, 146(12), 1117–1145. 

Relevance in Today’s World

Suicide and self-injurious thoughts and behaviors (STIBs) are major global health concerns. According to the World Health Organization (2019), suicide accounted for 1.3% of all deaths worldwide, making it the 17th leading cause of death in 2019. Nonsuicidal self-injury (NSSI; e.g., self-cutting in the absence of suicidal intent) is estimated to affect approximately 5.5% of adults and up to 17.2% of adolescents (Swannell, Martin, Page, Hasking, & St John, 2014). To help reduce this major public health crisis, there has been an increase in the effort to develop and refine treatments to reduce SITBs.  


To help determine the strength of existing treatments and to highlight treatment(s) that are particularly strong, this study set out to meta-analyze randomized controlled trials (RCTs) of SITB interventions published in the last 50 years.  

Importance of the Study   

Given the widespread global impact of SITBs and suicide death, suicide has been deemed a major public health issue with widespread efforts emerging to develop and disseminate intervention programs across the last few decades. In the United States alone, several major suicide prevention organizations were formed to help with this goal (e.g., the International Association for Suicide Prevention (1960), the Center for Studies of Suicide Prevention at the National Institutes of Mental Health (1967), the American Association of Suicidology (1968), and the American Foundation for Suicide Prevention (1987)). In 1999, the U.S. Surgeon General helped establish the National Hopeline Network (1-800-SUICIDE) and The National Suicide Prevention Lifeline (1-800-273-TALK) was launched soon after in 2001. Moreover, numerous treatments (e.g., Dialectical Behavioral Therapy, Collaborative Assessment and Management of Suicidality) were designed and adapted for people deemed at high risk for SITBs. These examples are just a few of the hundreds of treatments that have been created and tested to reduce SITBs.  


Many people who experience SITBs also experience a range of other mental, physical, and social issues. As a result, sometimes treatments targeting another problem (e.g., depression) are also used to simultaneously target SITBs. However, it isn’t clear whether treatments targeting SITBs are needed to reduce these outcomes, or whether treatments targeting other problems are similarly efficacious. Relatedly, it is not clear which treatments are best at reducing SITBs.  


We set out to conduct a quantitative review of all RCT-style studies in which SITBs were measured post-treatment. We focused on RCTs because they provide the best available estimations of SITB intervention efficacy and eliminate alternative explanations better than other study designs.  (See Figure 2 below for a diagram defining efficacy versus effectiveness). 


We hypothesized that, overall, SITB interventions have improved over time, that these interventions are moderately efficacious, and that the observed intervention effects would endure beyond the immediate treatment period. We also hypothesized that certain treatments, especially those designed for people at high-risk of suicide, would outperform other treatment methods.

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Figure 2. S. Adhikari. (2018). Efficacy vs Effectiveness [Chart]


The meta-analysis included 591 qualifying studies from 1,125 RCTs published in print or online between 1970 and January 1, 2018. Almost 90% of the articles were published since 2000 and 60.74% were published since 2010. The studies were found in PubMed, PsycINFO, Google Scholar, and using the following search terms: treatment, intervention, therapy, suicide, self-injury, self-directed violence, self-harm, self-mutilation, self-cutting, self-burning, and self-poisoning.  


To narrow the focus onto relevant studies, the researchers had specific inclusion and exclusion criteria (See Figure 1 for in/exclusion process). For example, the studies were required to randomly assign participants to a condition (treatment or control) and to assess 1+ SITB(s) post-treatment. Studies that only examined outcomes relevant to SITBs (e.g., attitudes toward SITBs, confidence in helping or treating individuals with SITBs) were excluded. The researchers also excluded studies that were not written in English and studies (or individual outcomes) that examined composites including alcohol use or death attributable to unintentional drug overdose. If study authors did not provide necessary statistical information like standard deviations and errors, their studies were also excluded. The researchers also excluded studies with redundant effect sizes for the same SITB treatment outcome found in multiple studies.  

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Relevant studies were then coded and checked by the lead authors, Dr. Fox and Dr. Huang. The codes included era of publication, SITB treatment effects, assessment time points, sample severity, sample age, specific intervention and target types, intervention characteristics, control characteristics, study quality, randomization, and design. The SITB outcome codes included: (a) NSSI (i.e., intentional self-harm enacted without suicidal intent); (b) self-harm (i.e., intentional self-harm where suicidal intent was not assessed or required); (c) suicide ideation/plans (any form of suicidal thought and/or plan); (d) suicide attempt (i.e., any intentional self-harm with nonzero intent to die); (e) suicide death (i.e., any intentional self-harm resulting in death); (f) hospital visits and hospitalizations due to SITBs; and (g) other/combined SITBs (e.g., suicidal gestures, outcomes combining both suicide attempt and death). Regarding study quality specifically, the researchers utilized the Quality Assessment Tool for Qualitative Studies and factors like selection bias and data collection methods to categorize studies as weak, moderate, or strong.  


We examined treatment effects on all (combined) SITB outcomes, as well as effects for each specific SITB outcome. Next, we examined whether key factors (e.g., treatment type, treatment target) impacted the strength of treatment effects. The moderators included publication era, age group, intervention type, control treatment type, intervention target, sample severity, therapist training, supervision/adherence check, study quality, study randomization, and study design. 


Characterizing studies to-date:

Suicide ideation was the most commonly reported SITB outcome examined (30.86%), with Other/Combined SITBs following behind at 26.72%. Approximately 60.32% of effect sizes used clinical samples that required participants to experience some form of psychopathology to participate in the study, whereas 28.17% of the effect sizes used self-injurious samples (i.e., prior SITBs were required as an inclusion criterion). Most of the studies (78.89%) had sample sizes smaller than 500, and the average sample age was 33 years old. Few studies focused exclusively on children and/or adolescents and older adults. Additionally, most studies examined psychotherapy (63.48%) and medication (46.72%) as treatments. The median treatment length was 12 weeks. Finally, more than half of the effect sizes were drawn from studies categorized as ‘weak study quality’ based on the Quality Assessment Tool.  

Treatment Efficacy Outcomes: 

Despite a near exponential increase in the number of RCTs conducted in the past 50 years, the intervention effects were weak overall and across each SITB outcome.

Moderator Outcomes:

Contrary to hypotheses, no intervention appeared significantly and consistently stronger than others in reducing SITBs. Treatment efficacy was similar across age groups; however, the efficacy among child/adolescent populations was slightly weaker in the few studies that focused on this age group. Unfortunately, treatments were not found to be stronger across time.

Conclusions & Future Directions  


Overall, the findings of the meta-analysis are disappointing and suggest weak effects for available SITB interventions. Results highlight the need for fundamental change in how the field approaches SITB interventions. The researchers suggest several directions for future research.  


In designing SITB intervention studies, researchers should ensure their studies include a sufficient sample size, obscure treatment condition, increase participant retention across phases, and include representative samples when possible. Considering that two populations (adolescents and older adults) demonstrate high rates of SITBs, future RCTs should intentionally recruit and test interventions on these two age groups. Moreover, we acknowledge that some interventions may be quite strong in their ability to reduce SITBs; yet, these were omitted from this particular meta-analysis due to a lack of RCTs for these interventions. In fact, few studies to date have used RCTs to test some of the most popular SITB interventions (e.g., suicide hotlines, means restriction, inpatient hospitalization, safety planning). Although ethical issues will need to be addressed, RCTs are a necessary step to testing whether and the degree to which such interventions are useful. 




Fox, K. R., Huang, X., Guzmán, E. M., Funsch, K. M., Cha, C. B., Ribeiro, J. D., & Franklin, J. C. (2020).           Interventions for suicide and self-injury: A meta-analysis of randomized controlled trials across                 nearly 50 years of research. Psychological Bulletin,146(12), 1117–                   



Swannell SV, Martin GE, Page A, Hasking P, St John NJ. Prevalence of nonsuicidal self-injury in                        nonclinical samples: systematic review, meta-analysis and meta-regression. Suicide Life Threat              Behav. 2014 Jun;44(3):273-303. doi: 10.1111/sltb.12070. Epub 2014 Jan 15. PMID: 24422986.  

World Health Organization. (2019). Suicide data. World Health                                                                            Organization.