Yoga's Mental Health Benefits
A new review of studies has confirmed yoga’s benefits on mental health conditions such as depression and ADHD.
Researchers from Duke University analyzed the results of 124 trials on how yoga can benefit people with certain neuropsychiatric disorders, and pinpointed 16 that met their criteria.
Of those studies included in their review, published in the journal Frontiers In Affective Disorders And Psychosomatic Research, they found evidence that yoga provides a benefit in depression, schizophrenia (when done alongside drug therapy), ADHD and problems with sleep. However, researchers didn’t find clear evidence showing yoga had a benefit on people with eating disorders or cognitive disorders.
Researchers noted that there were many limitations to the studies they were able to analyze, and that more research is needed to “fully translate the promise of yoga for enhancing mental health.”
Of course, a number of studies have analyzed the effects of yoga on conditions unrelated to the brain, as well.
Yoga on our minds: a systematic review of yoga for neuropsychiatric disorders
Meera Balasubramaniam1*, Shirley Telles2 and P. Murali Doraiswamy1,3*
1Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
2Indian Council of Medical Research Center for Advanced Research in Yoga and Patanjali Research Foundation, Bengaluru, India
3Duke Institute for Brain Sciences, Durham, NC, USA
Background: The demand for clinically efficacious, safe, patient acceptable, and cost-effective forms of treatment for mental illness is growing. Several studies have demonstrated benefit from yoga in specific psychiatric symptoms and a general sense of well-being.
Objective: To systematically examine the evidence for efficacy of yoga in the treatment of selected major psychiatric disorders.
Methods: Electronic searches of The Cochrane Central Register of Controlled Trials and the standard bibliographic databases, MEDLINE, EMBASE, and PsycINFO, were performed through April 2011 and an updated in June 2011 using the keywords yoga AND psychiatry OR depression OR anxiety OR schizophrenia OR cognition OR memory OR attention AND randomized controlled trial (RCT). Studies with yoga as the independent variable and one of the above mentioned terms as the dependent variable were included and exclusion criteria were applied.
The search yielded a total of 124 trials, of which 16 met rigorous criteria for the final review. Grade B evidence supporting a potential acute benefit for yoga exists in depression (four RCTs), as an adjunct to pharmacotherapy in schizophrenia (three RCTs), in children with ADHD (two RCTs), and Grade C evidence in sleep complaints (three RCTs). RCTs in cognitive disorders and eating disorders yielded conflicting results. No studies looked at primary prevention, relapse prevention, or comparative effectiveness versus pharmacotherapy.
There is emerging evidence from randomized trials to support popular beliefs about yoga for depression, sleep disorders, and as an augmentation therapy. Limitations of literature include inability to do double-blind studies, multiplicity of comparisons within small studies, and lack of replication. Biomarker and neuroimaging studies, those comparing yoga with standard pharmaco- and psychotherapies, and studies of long-term efficacy are needed to fully translate the promise of yoga for enhancing mental health.
Benefits of meditation and yoga for the mentally ill
Mental illnesses are asignificant global health concern, despite improvements in treatment modalities and access to care. The World Health Organization (WHO, 2011) has estimated that psychiatric disorders are the leading costs of disability adjusted life years world-wide, with recent figures indicating that 37% of the loss of healthy years from non-communicable diseases is from mental illnesses. The National Co-morbidity survey replication conducted in the United States estimated the 1-year prevalence of any psychiatric disorder to be 26.2% (Kessler et al., 2008). According to the WHO, depression ranked third among global disease burdens all over the world in 2004; it was reportedly the most important cause in middle and high income countries, while it ranked eight among the low income countries (World Health Organization, 2008). Depression was found to result in the greatest decrement in health, compared to asthma, angina, arthritis, and diabetes (Maussavi et al., 2007). Prevalence data for anxiety disorders, suggests that the lifetime prevalence and 12 month prevalence for any anxiety disorder are over 15 and 10%, respectively, with higher prevalence in developed countries (Kessler et al., 2009). Likewise, schizophrenia has been associated with significantly higher health care costs, unemployment rate, and morbidity (Goeree et al., 2005). Sleep complaints are often associated with a variety of psychiatric disorders. About 9–21% of the population has been estimated to have insomnia accompanied by serious day-time consequences which include chronic fatigue, irritability, low mood, memory impairments, and interpersonal difficulties (Moul et al., 2002). This problem has reached epidemic proportions in the United States, where almost 25% of adults consume sleep medications at some point in a year (National Sleep Foundation, 2005).
Yoga, with origins in ancient India has several sub-types (Table 1; Cook, n.d.), and incorporates physical postures (asanas), controlled breathing (pranayama), deep relaxation, and meditation (Javnbakht et al., 2009). In addition to low barriers to access, the scientific rationale for yoga effects on the mind are quite strong. All yoga practices are known to influence the mental state (Telles, 2010) – studies have noted benefits in children (Manjunath and Telles, 2004), adults (Vialatte et al., 2008), elderly (Krishnamurthy and Telles, 2007), and individuals with occupational stress (Vempati and Telles, 2000). In healthy individuals, biomarker studies suggest that yoga influences neurotransmitters, inflammation, oxidative stress, lipids, growth factors, and second messengers (Figure 1), in a manner largely similar to what has been shown for anti-depressants and psychotherapy. It is hypothesized that yoga combines the effects of physical postures, which have been independently associated with mood changes (Phillips et al., 2003), and meditation which increases the levels of Brain-derived neurotrophic factor (BDNF; Xiong and Doraiswamy, 2009). Other effects that have been noted include increased vagal tone, increased gamma-aminobutyric acid (GABA) levels, increase in serum prolactin, downregulation of the hypothalamic-pituitary-adrenal axis and decrease in serum cortisol, and promotion of frontal electroencephalogram (EEG) alpha wave activity which improves relaxation (Janakiramaiah et al., 1998, 2000; Kamei et al., 2000; Streeter et al., 2007).