By Rachel Bilski, The Minded Institute ™
Depression is a complex and multifaceted illness, thought to be caused by a delicate interplay of genetic, biochemical, psychological and circumstantial factors. Unlike the term used in general parlance to refer to low mood, clinical depression has a profound societal impact. As an intervention embedded within a wider treatment plan, yoga can provide a multifactorial and individualized response to this deeply personal illness, through physiological, psychological and social mechanisms.
DEPRESSION: A BACKGROUND
Even before 2020, depressive disorders were a leading contributor to the overall global burden of disease. The pandemic has since created an environment in which many determinants of poor mental health have been exacerbated, allowing depression to thrive. A recent Lancet study estimated an additional 53.2 million cases of major depressive disorder globally due to the impact of COVID, an undeniably gut-wrenching increase of 26% on an already enormous figure. According to the World Health Organization (WHO), depression will be leading cause of disability worldwide by 2030, though the fallout of the pandemic may well bring this date forward.
Sadness is an inevitable part of the human experience, especially in relation to adverse life events. The experience of depression becomes clinically significant when it starts to interfere on regular basis with daily life activity, going beyond normal fluctuations in mood to negatively impact an individual’s personal, social and professional life. Formal diagnosis relies on both the number and severity of symptoms beyond depressive mood, including changes in sleep, feelings of hopelessness, loss of interest in life, lack of motivation and concentration, suicidal ideation and thoughts of self-harm.
DEPRESSION AND YOGA
Treatment of clinical depression usually focuses on antidepressant medication prescribed in
conjunction with psychological therapies such as counseling or Cognitive Behavioral Therapy (CBT). One of the major challenges in treating depression is that it is often episodic and recurring over the course of a lifetime; for some it may develop in response to difficult circumstances, whilst for others it may appear to have no definable cause.
Despite some commonality, the way in which depression manifests is profoundly personal, and the experience of depression can vary widely from individual to individual. This is just one of the reasons yoga can provide such a potent intervention in the treatment of depression; yoga addresses multi-layered aspects of a person’s experience, and with such a wide variety of practices available, it can be tailored to meet the individual needs of the patient.
Yoga also has the potential to empower depressed individuals with tools they can immediately implement into their everyday life. This is particularly pertinent considering that there are often long waiting lists for access to talking therapies, potentially exacerbating the feelings of hopelessness and isolation concurrent with depression. Both during the interim waiting list period and in conjunction with psychological therapy, yoga can provide a self-help strategy for symptom management, while also preventing relapse when practiced in the long-term.
While medication can be a vital and even life-saving intervention for many, an estimated 10 – 30% of people with depression are found to be treatment resistant, defined as an inadequate response to courses of two different antidepressants. In such cases, yoga could bridge the gap by providing support while an appropriate medication is found.
Although there are almost 30 types of antidepressants, patients are most likely to be prescribed a selective serotonin reuptake inhibitor (SSRI). There is a wealth of research supporting the role of serotonin production not only in the treatment of depression, but also in susceptibility to depression and suicide. However, since long-term pharmacologic approaches are not always appropriate due to side-effects, increased tolerance over time and potential for relapse once medication is withdrawn, yoga may be considered as a nonpharmacologic method of increasing serotonin in depressed patients.
The efficacy of exercise for raising serotonin levels and decreasing symptoms of depression is well established. In the UK, National Institute for Health and Clinical Excellence (NICE) guidelines even recommend treating mild clinical depression with exercise rather than antidepressants, in order to address the poor risk–benefit ratio for antidepressant use in patients with mild depression. Yoga offers a gentle form of exercise which may feel more accessible for depressed individuals than high intensity workouts, due to the low energy and motivation often found in depression.
Another mechanism through which yoga may be effective in treating depression is via modulation of the body’s stress response. Not only is chronic stress a major risk factor for depression, but people with depression exhibit elevated levels of cortisol, one of the key stress hormones. High levels of cortisol are associated with brain changes that may perpetuate depressive symptoms; while the hippocampus and prefrontal cortex (involved in modulation of the stress response, emotion regulation and rational decision making) lose volume, the amygdala (responsible for triggering the stress response) becomes enlarged and more active. As such, elevated cortisol can contribute to increased stress levels and difficulty regulating emotions, causing a vicious cycle that can be hard to break for those suffering from clinical depression.
Numerous studies have demonstrated reduced levels of cortisol in those who practice yoga, in addition to increased heart rate variability (HRV), a measure of the body’s ability to adapt to
stressors. Additionally, yoga has been associated with a significant reduction in amygdala volume, and it is thought that the slow breathing integral to yoga may counter stress by inducing the body’s relaxation response. Considering the relationship between stress and depression, these findings provide encouraging support for the antidepressant benefits of yoga.
META-COGNITION AND MINDFULNESS
While medication can be beneficial in addressing the symptoms of depression, solely
pharmacological approaches do not treat the underlying risk factors and psychological
underpinnings that may cause depression in the first place. Dysfunctional thought processes such as depressive ruminations and suicidal ideation are not only a symptom of depression, but also form part of the mechanism that perpetuates the disorder.
Any effective treatment for depression must also address these distinctive thought processes,
explaining why psychological therapies such as CBT can have such a powerful impact. One of the shared principles between CBT and yoga is meta-cognition, an awareness of one's own thought processes and an understanding of the patterns behind them. The meditative component of yoga cultivates the ability to regulate thought processes more effectively, in turn allowing for the development of emotional self-regulation skills.
In particular, mindfulness practices help to train the mind to focus on immediate experience, in turn reducing the propensity to ruminate about the past or worry about the future. Through a process of cultivating a non-judgmental, neutral perspective of thoughts, feelings, sensations and emotions, mindfulness provides a solid foundation from which to begin modifying thought processes over time.
A growing body of evidence has begun to elucidate neuroscientific mechanisms behind these effects, such as increased cortical thickness and decreased amygdala volume as a result of mindfulness practices. Additionally, mindfulness strengthens the functional connections between the amygdala and the pre-frontal cortex, paving the way for better emotion regulation and decreased reactivity, both key components of any psychological treatment approach for clinical depression.
In addition to physiological and psychological mechanisms, lack of social support is a major
contributing risk factor for depression. Studies have shown that low social support is associated with higher levels of depression, and since low mood may negatively influence social behavior, targeting social factors is vital in any treatment plan for depression.
Social ramifications are common for those with depressive disorders, such as the avoidance of occasions with friends and family, poor professional performance and no longer taking part in activities of interest. The isolation this causes can perpetuate symptoms associated with low-mood, potentially worsening the condition over time.
One of the interesting facets of yoga as an intervention is that it is by nature a non-judgmental
practice, open to all regardless of ability or previous experience. Yoga classes tend to be warm and welcoming spaces, providing a supportive sense of community without the pressures of social participation. These factors are especially important for people living with depression, as feelings of worthlessness and low self-esteem may be a barrier to physical activity and the benefits it provides.
In targeting physiological, psychological and social aspects of clinical depression, yoga provides a potent prescription. Both a self-help strategy for symptom management and a means of preventing relapse when practiced in the long-term, yoga can help to empower depressed individuals to manage the ebbs and flows of their condition. With a strong and growing evidence base underlying the mechanisms of yoga’s benefits, there is considerable support for yoga to considered as an effective adjunctive treatment for clinical depression, alongside pharmacological and psychological approaches.