You might have heard that yoga is good for your mental health. But, why is that? What does yoga specifically do that impacts your mental functioning? You know you might feel more chill and relaxed after a yoga class you might never really know why. I hope I can explain this phenomenon a little more and give you more incentive to keep practicing.

In our body, our autonomic nervous system controls the functioning of the organs. The autonomic nervous system is broken down into two parts, the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). These two systems work in tandem to regulate our body functions, when one is higher functioning, the other is lower functioning. The SNS is responsible for our stress response and is often called our “fight or flight response system.” The SNS increases our breathing rate and blood pressure to get more oxygen to the muscles and causes blood sugar to increase to fuel those muscles. The SNS also shuts down organ functioning that isn't needed in a fight, like digestion, immune system work, and thinking. The PNS system is the opposite system and is often called the “rest and digest system.” This system slows down the heart rate, slows down breathing, and tells the shut down systems to resume activity once the stressor is over.

So, how are the SNS and PNS impacted by yoga? Yoga (including asanas, breathing practices, and meditation) have been found to activate the PNS system. If the PNS system is about rest and digest, then doing yoga activates the relaxation response. Some parts of yoga (like sun salutations or certain breathing exercises) activate the SNS during practice because they are vigorous, but they are then followed by more relaxing asanas and breathing, which can lead to a deeper relaxation response than just soothing poses and breathing alone.

Yoga has also been shown to impact mental health because of how it impacts the brain. Researchers have studied yogis and found that certain parts of the brain show more gray matter (brain cells) after years of practice. These parts include our hippocampus, which plays a role in memory, and our prefrontal cortex, which plays a role in decision making, concentration, and impulse control. They have also found that yoga can influence the size of our amygdala, which is the brain’s smoke detector. The bigger the amygdala, the more sensitive we are to stress, so having a smaller amygdala means you’re less sensitive to stressors. During yoga, certain parts of our brain are resting, including the frontal lobe and parietal lobe. Our frontal lobe is responsible for thinking, planning, and reasoning and the parietal lobe handles sensory information. The parietal lobe plays a role in pain sensitivity and if this part is resting, we might not be as sensitive to pain. These parts of the brain play a role in stress (thinking and sensations activate a lot of stress) so by letting them rest during yoga, the body can relax as well.

Another way that yoga impacts mental health is by playing a role in the brain’s chemical balance, which influences your mental health. Serotonin plays a key role in stabilizing our mood, sleep, digestion, and sleep. Too little serotonin is associated with depression and antidepressants work on increasing serotonin levels in the body. GABA is a neurotransmitter that plays a role in anxiety and is often influenced by anti-anxiety medications. Melatonin is part for our sleep/wake cycle that is often taken as an over the counter supplement. Oxytocin, the famous pain reducer and love molecule, leads us to feeling less pain and more desire for social connection. BDNF plays a role in brain cell growth and maintenance. Glutamate is an excitatory neurotransmitter and plays a role in learning and memory. Acetylcholine plays part in your body movements as well as memory. And finally, endorphins serve as more pain reducers. Studies have shown that yoga increases the levels of all of these chemicals, which could lead to improved mood, decreased anxiety, increased desire for social connection, better sleep, better digestion, better memory, feeling less pain signals, and more brain development/maintenance.

Norepinephrine is a neurotransmitter and hormone that plays a role in stress, mood, and concentration. Dopamine is part of the reward-center of the brain. Yoga has been shown to decrease levels of dopamine and norepinephrine, meaning you don’t need to do as many reward-based behaviors (that can be addictive like drugs or alcohol) and you might have overall less stressful feelings in your body.

Yoga has also been shown to decrease activity in the hypothalamic-pituitary-adrenal (HPA) axis in the brain, which is responsible for stress hormones like cortisol. The less the HPA axis is active, the less cortisol you having roaming through the body. The human body was not designed for high amounts of cortisol to be in the system as much as modern living influences, so the less cortisol you have in your body, the better off you can be mentally and physically.

Learning that moving our body, regulating our breath, and meditating can influence our mental health is what sold me on the idea of having a yoga practice. This blog is just skimming the surface of the impacts on yoga on mental health and there are whole courses on this topic that I encourage you to look into those if you want more details. However, it is important to for me to stress I am never going to diminish the importance of talk therapy or medications in the treatment of mental health. But, research has clearly shown that by adding yoga as a supplement to those gold standards of mental health treatment, we can improve our treatments and impact overall health. This is why I encourage all of my clients to add yoga to their treatment plans. If you would like to learn more about how yoga impacts mental health or to schedule a private yoga lesson geared specifically to your mental health needs, please contact me here to schedule a consultation to discuss more.

References

Weber, K. & Lester, A. (2017). Subtle Yoga for Trauma Recovery: A One Day Introduction [Class handout]. Charlotte, NC: Charlotte Area Health Education Center.

Weber, K. & Lester, A. (2017). Subtle Yoga for Behavioral Health Professionals Intensive 1: Anxiety and Depression [Class handout]. Asheville, NC: Mountain Area Health Education Center.

Weber, K. (2017). Yoga, Positive Psychology, and Neuroplasticity [Class handout]. Asheville, NC: Subtle Yoga.

Weber, K. & Lester, A. (2017). Subtle Yoga for Behavioral Health Professionals Intensive 2: Trauma, Addiction, and Recovery [Class handout]. Asheville, NC: Mountain Area Health Education Center.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3555015/

https://yogainternational.com/article/view/your-brain-on-yoga

https://yogamedicine.com/how-yoga-changes-your-brain/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6971819/

https://www.neuroscientificallychallenged.com/blog/2014/5/31/what-is-the-hpa-axis

https://www.yogajournal.com/teach/the-scientific-basis-of-yoga-therapy/

https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/serotonin

https://www.webmd.com/mental-health/what-is-dopamine

https://medlineplus.gov/genetics/gene/bdnf/

https://www.verywellmind.com/what-is-acetylcholine-2794810