Yoga for mental health : evaluation of yoga interventions for reducing depression and anxiety, and improving well-being

Abstract

Depression and anxiety are leading causes of disability worldwide and major contributors to the global burden of disease. Current treatments are primarily pharmaceutical and psychological. However, questions remain about the effectiveness of, and barriers to access to conventional treatments. There is increasing interest in complementary, mindbody, and lifestyle approaches, including yoga. Previous research suggests potential benefits of yoga in reducing depression and anxiety. The aim of this thesis was to investigate the potential benefits of yoga in managing depression and anxiety, and evaluate associated improvements in mental health and wellbeing. Current concepts of depression, anxiety and their comorbidity are reviewed, as are conventional approaches to management and treatment of the disorders. Positive psychology approaches to mental health, and the opportunity for development of nonconventional approaches to therapeutic interventions, including yoga as a form of mindbody mental health intervention are considered. Prior research into the benefits of yoga for depression and anxiety has demonstrated potential benefits however, the results and interpretations must be treated with caution, due to methodological limitations and heterogeneity of interventions used. In response to concerns of heterogeneity of yoga interventions used in prior research, a consensus-based yoga intervention was developed utilising a Delphi method study. From the results of the study, a consensus statement was produced on components of yoga practice that could be used in research evaluating yoga for reducing depression or anxiety and improving well-being. Central to this thesis and testing of the hypotheses, was the conduct of a clinical trial to evaluate a yoga-intervention for reducing depression and anxiety, and increasing wellbeing. The effectiveness of the consensus-based yoga intervention was evaluated in a randomised controlled trial (RCT), with an additional crossover trial design. A sample of 101 people with depression and/or anxiety participated in an RCT comparing a 6-week yoga intervention with waitlist control. Both groups continued other treatments as usual. The control group was offered the yoga following the waitlist period. Participants were also assessed at 6-week follow-up. Primary outcome measures were the depression and anxiety sub-scales of the Depression Anxiety and Stress Scale (DASS21). Secondary outcome measures included the stress sub-scale of the DASS21, total DASS score, Kessler Psychological Distress Scale (K10), Short Form Health Survey (SF12), Scale of Positive and Negative Experience (SPANE), Flourishing Scale (FS), and Connor-Davidson Resilience Scale (CDRISC2). Results of the RCT showed a statistically significant reduction of DASS depression scores in the yoga group relative to the waitlist group (AMD -4.30; 95% CI's -7.70, -0.91; p=0.01; effect size -0.44). The reduction of DASS anxiety scores with yoga relative to waitlist was not statistically significant (AMD -1.91; 95% CI's -4.58, 0.76; p=0.16). However, influential outlying data were observed in changes from pre to post anxiety scores (with Cook's distance values > 0.04). After trimming of these data, group differences on anxiety scores were statistically significant (AMD -2.53; CI's -4.71, -0.35; p=0.02; effect size -0.40). Statistically significant differences in favour of yoga were also found on secondary measures: total DASS (p=0.03), K10, SF12 mental health, SPANE, FS and resilience scores (p

Date of Award	2017
Original language	English