Yoga for Depression and Anxiety: A Review of Published Research and Implications for Healthcare Providers

Over the past few years, patients, clinicians, researchers, and yoga practitioners have shown increasing interest in the use of yoga as a way to manage or treat depression and anxiety. Yoga is a discipline and practice with origins in India. In the united States, most people practice hatha yoga, which includes physical postures (asanas) and can include breath control and practices (pranayama) and meditation (dhyana). There are many different styles of hatha yoga – for example, Vinyasa or Iyengar. Hatha yoga classes can vary in numerous ways: some classes may involve flowing from one posture to another; others may be more focused on alignment and holding postures. Classes can range from very vigorous and aerobic in nature to very gentle. In some classes, teachers may focus on teaching mindfulness. That is, teachers may instruct yoga students to focus on breathing and bodily sensations in a non-judgmental way as the students move or hold postures.

Yoga might be appealing to people who struggle with depression and anxiety for many reasons. It is affordable and readily accessible in many areas. In addition to the fact there are many yoga classes in the community, yoga students can also use instructional DVDs and books to practice at home. There are modified classes for people with special concerns, such as pregnant women. Yoga may also alleviate physical pain,¹ a common comorbidity among people with depression or anxiety. Yoga can easily be used in combination with traditional mental health treatments. Finally, some people may like the fact that yoga focuses on promoting good mental and physical health, and is not focused on correcting a deficit or treating poor health.

There are many possible mechanisms by which yoga might have an impact on depression or anxiety. We highlight two types of mechanisms here: cognitive/affective and biologic.

First, in a yoga class, a student may be directed to direct his/her attention to present-moment thoughts, feelings, and body sensations in a non-judgmental way. This practice of mindfulness, when extended into everyday life, may help one to focus on current experience, rather than ruminating on the past or worrying about the future. Further, the emphasis on a non-judgmental approach may help to decrease self-criticism. Learning to attend to current experience, including current thoughts and feelings, can also teach one that thoughts and feelings are transient mental events, and that negative (and positive) feelings will fluctuate and change. Mindfulness-based therapies have a demonstrated impact on depression and anxiety symptoms.²

Yoga-based practices may serve to regulate the autonomic nervous system. Autonomic nervous system dysfunction is associated with depression³ and anxiety.⁴ Yoga practices may modify underactivity of the parasympathetic nervous system (PNS) and GABA systems in part through stimulation of the vagus nerves, which are the primary peripheral pathway of the PNS. There is some research to suggest that yoga does indeed increase PNS activity and increase GABA levels in the thalamus, and that these increases are correlated with improved mood.⁵ Researchers have also hypothesized yoga may have a positive impact on related biologic pathways. Yoga may reduce hypothalamic-pituitary-adrenal axis activation, although evidence to date is inconsistent.⁶ Finally, there is some evidence yoga may serve to decrease inflammation (e.g.,⁷). Change in these biologic pathways may affect the underlying pathophysiology of depression and anxiety.

As can be seen by this literature review, with the possible exception of unipolar depression, there are relatively few scientific studies evaluating the impact that yoga may have on symptoms of mood, anxiety disorders, and PTSD. Further adding to the difficulty of making conclusions from this literature, there are important differences between studies, and many studies suffer from methodologic limitations. We highlight a few key issues here. First, the style of yoga varies significantly between study interventions – with different emphasis placed on how gentle vs. vigorous the practice is and the degree to which pranayama, meditation, and mindfulness are emphasized. Some of the yoga interventions described above were not hatha yoga – i.e., they were primarily focused on pranayama and not at all focused on asana practice. Second, yoga interventions also differ in “dosage”: i.e., the length of classes, the number of classes per week, and the degree to which home practice is encouraged. Third, trials employ a variety of control groups, ranging from a relatively weak control groups (i.e., no treatment) to stronger control groups (i.e., physical activity or another type of class that controls for time and attention). Fourth, many studies do not include an assessment of the key outcome measure (e.g., depression or anxiety symptoms) performed by an evaluator who is blind to treatment assignment.

We provide recommendations for healthcare providers in light of the current level of evidence of yoga for depression and anxiety. It is possible that an individual with a mood or anxiety disorder will be interested in trying yoga. A healthcare provider might advise his/her patient that there are many different styles of yoga in the community, and that the patient may want to try a class for a few weeks, evaluate whether the class seems to be comfortable and helpful, and, if not, consider trying a different class. If the patient is not physically fit, it is wise to start with a “gentle” or “beginner's” yoga class. Classes that emphasize mindfulness practices may be particularly helpful for people with depression or anxiety. Although there is no formal licensure for yoga teachers, yoga teachers who are Registered Yoga Teachers (RYTs) with the Yoga Alliance have gone through a formal training program approved by the Yoga Alliance. Thus, the patient may want to choose a class taught by a RYT.

Although yoga may be beneficial, the patient and healthcare provider should be aware of possible risks of engaging in yoga. In studies described above, investigators often did not report on a systematic assessment of adverse events, and thus there is very little data available on possible risks of yoga participation. However, in a survey study of people with bipolar disorder who practiced yoga, potential risks cited included: practices such as rapid breathing or extended meditation possibly leading to symptom exacerbation (mania or depression), physical injury, and negative comparison to other students.¹² Other possible risks include dehydration resulting from the combination of a heated room and psychotropic medications, or strong negative psychological reactions (such as panic attacks, flashbacks, or hallucinations) to extended meditation sessions. When choosing a class, a patient will want to be mindful of his/ her own vulnerabilities and risks, including risks associated with psychotropic medications.

In sum, there is preliminary evidence that yoga may be helpful for depression, anxiety, or PTSD. The evidence is strongest for unipolar depression. Healthcare providers can help patients evaluate whether a given community-based yoga class is helpful and safe for them.

For further reading and suggestions for practice, see Yoga for Depression: A Compassionate Guide to Relieve Suffering Through Yoga by Amy Weintraub (Harmony Books, 2003).