The role of physical activity in the treatment of mental illness

This thesis aimed to explore the role of physical activity as an intervention strategy for the treatment of mental illness, with a focus on posttraumatic stress disorder (PTSD). A meta-analysis of randomized controlled trials (RCTs) incorporating physical activity interventions for established mental illness found a large effect of physical activity on depressive symptoms (n=20; standardised mean difference, SMD=0.80). To evaluate the impact of a physical activity intervention on PTSD, an assessor-blinded RCT was conducted. In total 81 participants were randomised to receive either usual care (n=42), or an individualised 12-week exercise program in addition to usual care (n = 39). PTSD symptoms were significantly reduced in the intervention group compared to the usual care group (mean difference at follow-up adjusted for baseline values = -5.4, 95%CI -10.5 to -0.3, p=0.04, n=58). There were also significant between-group differences at follow-up for depression scores, waist circumference, sleep quality and time spent sitting. The trial results support the addition of structured exercise to usual care for PTSD patients. Improving access to, and the provision of, clinical exercise programs within as part of treatment for patients with mental illness is warranted given the results of the studies presented in this thesis