Research evidence on the effectiveness of yoga in reducing depression
As per the Harvard Mental Health Letter, recent studies suggest that yoga therapy can reduce the impact of stress, reduce anxiety, and depression. Just like meditation, yoga is a self-soothing technique and improves energy.
While depression damages the concentration and mood and draining the motivation, yoga offers a form of exercise to people with depression. Moreover, yoga is gentle and very relaxing. Also, it can be performed in an enjoyable way to begin an exercise regime. One need not have high skills to practice yoga, anyone can start with it and yoga sessions are designed to offer a supportive sense of community. Such support is important because depressed people have low self-esteem and feel worthless that prevents them from participating in physical activities.
Related: The Science behind Yoga and Stress
A large body of research suggests that yoga can reduce the levels of cortisol the stress hormone in our body. This is because breathing exercises induce the body’s relaxation response. And when practiced together with mindfulness meditation (another part of yoga) the study subjects showed a decrease in cortisol levels. Other studies demonstrated that yoga also reduces the size of the amygdala which is enlarged due to excess cortisol during stress and depression.
Harvard Medical School’s website mentioned an interesting study conducted at the University of Utah, investigated the effect of yoga on the stress response. The researchers observed the participants’ responses to pain when subjected to more or less painful thumbnail pressure. 12 of these participants were yoga practitioners, 14 of them were diagnosed with fibromyalgia or stress-related illness and 16 were healthy volunteers.
Based on functional MRI results it was concluded that yoga practitioners had the highest pain tolerance and lowest pain-related brain activity, whereas those having fibromyalgia perceived pain at lower pressure levels compared to the remaining two groups. Also, people with high stress had the greatest activity in areas of the brain associated with the pain response. The study emphasizes on effectiveness of yoga, which can help a person regulate their stress and, therefore, pain responses.
In a 2017 systematic review (including randomized control trials, quasi-experimental, and pretest/posttest) titled, “The Efficacy of Yoga as a Form of Treatment for Depression”, 23 yoga interventions (published between 2011 and May 2016) were evaluated, where the majority were 6 weeks or longer. The review concluded that yoga is effective in reducing depression.
Two randomized control trials tested the efficacy of 12-week yoga intervention in people with major depressive disorder. Results showed an increase in brain GABA associated with specific yoga postures and breathing practices in depressed patients when compared to healthy control participants. Also, there was an improvement in mood and anxiety measures with scores equivalent to those of non-depressed individuals. A first time that yoga postures have been associated with a positive correlation between acute increases in thalamic GABA levels.
Another study showed reduction in suicide ideation (without intent) for people with depression after Iyengar yoga intervention.
Lindsey Hopkins conducted a study involving 23 male veterans to study the effectiveness of hatha yoga focusing on physical exercises, meditation, and breathing exercises for 8 weeks (and twice a week). People with high scores on depression scale before intervention demonstrated low scores after intervention. Besides, participants enjoyed the sessions and rated it 9.4 on a scale of 10.
A similar study (involving 52 women aged 25-45 years separated into randomized and control groups) on the effectiveness of Bikram yoga against depression showed a significant reduction in symptoms of depression after 8 weeks.
It can be concluded that the existing literature well-established the efficacy of yoga in decreasing the symptoms of stress and depression. Also, these studies support the need for more investigation in this field with larger samples and effective study designs to prove the effectiveness of yoga on mood disturbances.