Physical Exercise as a Treatment for Non-Suicidal Self-Injury: Evidence From a Single-Case Study
To the Editor: Nonsuicidal self-injury refers to deliberate damage to one’s own bodily tissue without suicidal intent. Nonsuicidal self-injury is a pervasive behavior problem, yet effective treatments are lacking. Research has found that people engage in nonsuicidal self-injury for several different reasons, including tension relief and the induction of pleasurable affective states (1) . Preliminary evidence suggests that the release of endogenous opioids may be central to this process of emotional regulation (2) . We hypothesized that aerobic physical exercise, which has been shown to regulate mood (3) and stimulate the release of beta-endorphin (4) , would decrease the frequency of nonsuicidal self-injury. We report on the results of a single-case study demonstrating the effectiveness of physical exercise as a treatment for nonsuicidal self-injury.
“Ms. A” was an overweight 26-year-old woman with a 13-year history of ongoing psychological and pharmacological treatment for persistent nonsuicidal self-injury, including one inpatient hospitalization for nonsuicidal self-injury within the past year. Ms. A was receiving twice-weekly outpatient psychotherapy for the duration of this study. In an initial baseline assessment, she reported 2.25 episodes of nonsuicidal self-injury per week over the previous month, including self-hitting and head-banging.
We provided Ms. A with a 60-minute workout video, instructing her to exercise three times per week and to exercise in response to nonsuicidal self-injury urges at any time. We also provided a daily assessment form in which she recorded mood and self-injurious urges (both on 0–9 scales) and behaviors.
The frequency of Ms. A’s nonsuicidal self-injury decreased immediately after the introduction of exercise to 0.37 times per week during a five-week experimental phase. She then independently discontinued exercise. During this quasi-experimental return to baseline, nonsuicidal self-injury increased to 2.33 times per week. When exercise was re-introduced, nonsuicidal self-injury decreased to 0.00 times per week for the remainder of the study.
Overall, nonsuicidal self-injury frequency was significantly lower during exercise phases (M=0.29, SD=0.49) relative to nonexercise phases ([M=2.20, SD=0.45] t=6.93, df=10, p<0.001). Moreover, analysis of mood ratings showed an increase from before exercise (M=2.23, SD=0.86) to after (M=4.77, SD=1.48) exercise (t=7.56, df=50, p<0.001). When Ms. A exercised in direct response to self-injurious thoughts, exercise acutely reduced her urge to self-injure, from before (M=3.00, SD=1.87) to after (M=0.15, SD=0.38) exercise in every single instance (t=5.38, df=24, p<0.001). An 8-week follow-up interview revealed sustained improvement in Ms. A’s mental and physical well-being and a decrease in body weight by 20 pounds.
These initial results are promising, and future research is needed to further investigate the effectiveness of exercise as a treatment for nonsuicidal self-injury.
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