Impact of yoga and physical exercise on psychological wellbeing among substance abusers: a randomized controlled trial

Substance use disorder is a pattern of recurrent use of illicit substances that leads to severe psychosocial imbalance and recurrent relapse. The study was to evaluate the efficacy of a yoga-based intervention as an add-on in enhancing psychological wellbeing, compared with physical exercise among substance abusers.In this randomized controlled study, 96 male participants with substance use disorder from a residential rehabilitation treatment center, Kathmandu, Nepal, were randomly allocated into two groups namely the yoga group (n=48, mean age ± SD=25.18 ± 6.43) and the physical exercise group (n=48, mean age ± SD=25.02 ± 5.02). The participants in the yoga group attended the 90 min yoga sessions for 12 weeks (six days per week) whereas the physical exercise group attended exercise sessions for the same duration. Above mentioned interventions were in addition to standard rehabilitation treatment. The study measured the Self-Control, Anxiety, Depression, Sleep parameters, and Mindfulness at the baseline and after 12 weeks of intervention.A significant enhancement in self-control was observed in both the yoga (p<0.033, d=0.33) and the exercise group (p<0.038, d=0.32). Yoga group showed significant improvement in mindfulness score (p<0.017, d=0.37), whereas exercise group did not show any significant changes in mindfulness (p<0.169, d=0.21). The depression and anxiety scores reduced significantly in both yoga (p<0.044, d=0.31; p<0.025, d=0.35 resp.) and exercise (p<0.032, d=0.34. p<0.039, d=0.32. resp.) group. Furthermore, significant reduction was seen in sleep disturbance after yoga (p<0.001, d=0.52) and exercise (p<0.001, d=0.78) intervention. The sleep - somnolence score reduced significantly only in yoga group (p<0.020, d=0.36). The magnitude of improvement was higher in the yoga group than physical exercise group on self-control, mindfulness, depression, anxiety and some sleep parameters, however the between group differences could not reach to the level of significance.The 12 week yoga intervention did not appear to be significantly more effective than the 12 week physical exercise program on psychological wellbeing in male participants with substance use disorder. However, greater improvement in psychological wellbeing was observed within the yoga group. In future, a multi-centric study with robust design, larger sample size and longer follow-up is required to conform the present results and to find out the difference between the impacts of yoga and physical exercise on psychological wellbeing in substance abusers.