Reduced impulsivity
The researchers found a difference in post-intervention suicidal ideation when they compared exercise participants to all control and inactive control participants (standardized mean difference, –1.09; 95% confidence interval, –3.08 to 0.90; P = .20, k = 5). However, the difference was not statistically significant.
Similarly, there was no significant difference (P = .60) in suicidal ideation incidence for subgroup analyses that stratified data among participants with depression, sickle cell disease, and suicidality.
All-cause discontinuation also did not significantly differ between participants who were randomly assigned to exercise interventions versus all controls or inactive controls (odds ratio, 0.85; 95% CI, 0.38-1.94; P = .86, k = 12 and OR, 0.81; 95% CI, 0.25-2.68; P = .70). All-cause discontinuation also did not differ between participants randomized to exercise versus active controls (OR, 0.94; 95% CI, 0.38-2.32; P = .79, k = 3).
Likewise, there were nonsignificant differences between participants who underwent aerobic exercise and strength training (P = .20).
However, there were some nonsignificant differences when comparing participants with depression and stress who received the exercise intervention versus controls (P = .46).
There was a significant reduction in suicide attempts in individuals who participated in exercise interventions versus inactive controls (OR, 0.23; 95% CI, 0.09-0.67; P = .04, k = 2). On the other hand, there was no significant difference in mortality (P = .70).
Most of the studies (82%) were “at high risk of bias,” the authors note. In addition, the analysis was limited because the included studies were “few, underpowered, and heterogeneous.”
Dr. Fabiano hypothesized that the lack of effect on suicidal ideation or mortality is “likely due to the limited sample size.” As additional RCTs are conducted, Dr. Fabiano expects to see decreases in both suicidal ideation and suicide attempts.
The findings may “be explained by the ideation-to-action framework, which suggests that the development of suicidal ideation and the progression to suicide attempts are distinct processes with different influential factors,” he said.
Increased levels of exercise have been “shown to reduce emotional impulsivity and, as it has been shown that most suicide attempts are characterized by impulsivity and low lethality, we hypothesize that regular exercise serves as a protective factor against suicide attempts,” he said.
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Commenting on the study, Fabien Legrand, PhD, a lecturer in clinical psychology, University of Reims Champagne-Ardenne, Reims, France, said that the impact of physical activity is of “particular interest” to him because it is closely linked to his research activity, where he has “been exploring the antidepressant effects of exercise for more than 15 years.”
A small pilot study conducted by Dr. Legrand and colleagues found rigorous physical activity to be helpful in reducing hopelessness in psychiatric patients, compared with controls. “This result is of particular relevance for suicidal patients, since it has long been documented that hopelessness is one of the main triggers of suicide ideation and suicide attempts,” he said.
Initially, Dr. Legrand “warmly welcomed” the current review and meta-analysis on the exercise and suicide. However, he felt that the paper fell short in accomplishing its intended goal. “After a thorough reading of the paper, I don’t think that the information provided can be used in any way,” he stated.
“The paper’s title – ‘Effects of Physical Exercise on Suicidal Ideation and Behavior’ – does not do justice to its content, since 9 of the included 17 RCTs did not measure changes in suicidal ideation and/or suicidal behavior following participation in an exercise program,” noted Dr. Legrand, who was not involved with authorship or the current analysis.
The study was funded by the University of Ottawa department of psychiatry. Dr. Fabiano declares no relevant financial relationships. The other authors’ disclosures are listed in the original article. Dr. Legrand declares no relevant financial relationships.
A version of this article first appeared on Medscape.com.