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How Deep Relaxation Affects Brain Chemistry

Deep relaxation and meditation ultimately slows down brain waves.

Gareth Southwell, used with permission
Source: Gareth Southwell, used with permission

Deep relaxation and meditation have long been known to help with anxiety disorders and major depression. Because both anxiety disorders and major depression reflect an imbalance in brain chemistry, it would seem that relaxation techniques can influence brain chemistry. How do they do that?

The sympathetic response to stress and fear consists of a rapid release of stress chemicals into the bloodstream, including cortisol, adrenaline, and noradrenaline. The reaction to fear is almost instantaneous, but shutting down the stress system takes more time. For people with anxiety disorders, the stress system never shuts down.

Deep relaxation and meditation can help shut down the release of stress chemicals into the bloodstream simply by counteracting some of the effects of these chemicals. The stress chemicals cause muscles to tense up. By consciously deciding to relax, you counteract the stress chemicals.

Stress chemicals send impulses to the sympathetic nervous system, which is responsible for keeping the body active. When the sympathetic nervous system is active, the opposite-functioning parasympathetic nervous system is inhibited.

Deep relaxation and meditation allow the parasympathetic nervous system to become active by down-regulating the sympathetic nervous system. What happens is that once the sympathetic nervous system shuts down, the inhibitory neurotransmitter GABA is no longer prevented from acting on the GABA receptors that are present everywhere in the nervous system.

GABA is the brain’s own tranquilizer. It down-regulates the brain’s electricity. When GABA is active, brain waves in the slow theta range (4 to 7 Hertz) increase. While brain waves in the higher frequency range play an important role in concentration, communication, and problem-solving, theta waves are important for maintaining a good balance in brain chemicals.

Deep relaxation and meditation thus ultimately slow down brain waves, which rejuvenates the brain’s chemistry and gives rise to a calmer state of mind, even after the relaxation or meditation ends.

More from Berit Brogaard D.M.Sci., Ph.D
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