Randomized controlled trial of bikram yoga and aerobic exercise for depression in women: Efficacy and stress-based mechanisms.

BACKGROUND: The current study presents a randomized controlled 8-week trial of Bikram yoga, aerobic exercise, and waitlist for depression. Bikram yoga was chosen specifically for its standardized nature. Further, we examined changes in three stress-related constructs-perceived stress, rumination, and mindfulness-as mediators of antidepressant effects. METHOD: Fifty-three women (age 18-65; 74% White) with a unipolar depressive disorder were randomly assigned to one of the three conditions. Response was defined as >50% reduction on the Hamilton Rating Scale for Depression (HAM-D). Remission was defined as no longer meeting criteria for depression and a HAM-D ≤ 7. Self-reported perceived stress, rumination, and mindfulness were assessed weekly. RESULTS: In the intention-to-treat sample (n = 53), response rates were significantly higher in the Bikram yoga (61.1%; χ2 = 10.48, p = .001) and aerobic exercise (60.0%; χ2 = 10.44, p = .001) conditions relative to waitlist (6.7%). In the completer sample (n = 42), 73.3% (χ2 = 11.41, p = .001) of women in yoga and 80.0% (χ2 = 13.72, p < .001) in exercise achieved response compared to 8.3% in waitlist. Reductions in rumination significantly mediated HAM-D change for both active treatments, and mindful acceptance was a partial mediator in the exercise condition. LIMITATIONS: The sample was small in size, consisted of women only, and was ethnically homogenous. Inter-rater reliability was not assessed, aerobic exercise was not standardized, and mediators were assessed by self-report. CONCLUSIONS: Bikram yoga showed descriptively similar efficacy to aerobic exercise and both may work, in part, by helping individuals interrupt negative thinking.

The impact of acute mental stress on brachial artery flow-mediated dilation in women diagnosed with depression.

Endothelial function, assessed by flow-mediated dilation (FMD), may be transiently attenuated in healthy adults following acute mental stress. However, the impact of acute mental stress on endothelial function in the context of clinical depression is unknown. This study examined the impact of acute mental stress on FMD in women with a diagnosis of a depressive disorder. Forty-three otherwise healthy women (33 ±â€¯14 years) participated. Brachial artery diameter and blood velocity were assessed with ultrasound. FMD was assessed immediately prior to and 15 min following the Trier Social Stress Test (TSST). The FMD protocol included 5 min of forearm cuff occlusion (pressure = 250 mm Hg), followed by release. Shear stress was estimated by calculating shear rate (SR = brachial artery blood velocity/diameter). Stress reactivity was assessed via changes in mean arterial pressure (MAP), heart rate (HR) and salivary cortisol. Results are mean ±â€¯SD. A significant stress response was elicited by the TSST [MAP, HR and salivary cortisol increased (p < 0.05)]. Neither the SR stimulus nor FMD response differed pre-versus post-stress (p = 0.124 and p = 0.641, respectively). There was a modest negative correlation between cortisol reactivity and change in FMD from pre- to post-stress (R = -0.392, p = 0.011). To conclude, acute mental stress did not consistently impair endothelial function in women diagnosed with a depressive disorder; however, higher cortisol reactivity may increase the likelihood of post-stress endothelial dysfunction. Further research is required to better understand the factors influencing the relationship between acute mental stress, cortisol and endothelial function in women with depression.