The Science
Yoga, GABA, and How Fast the Effect Fades
Twelve weeks of yoga and coherent breathing raised thalamic GABA in people with major depression — and the rise appears to be short-lived, which is an argument for regularity.
Yoga practice linked to increased brain GABA and reduced depressive symptoms.
Twelve weeks of Iyengar yoga plus coherent breathing at five breaths a minute, in people meeting criteria for major depressive disorder. Thirty-two were randomized to one of two doses — three ninety-minute sessions a week plus four homework sessions, or two sessions plus three — and twenty-eight completed the scanning. Depression scores improved significantly in both groups.
The chemical finding is the interesting one. Thalamic GABA rose significantly in the lower-dose group, with a trend across the full cohort, comparing the baseline scan to the scan taken immediately after a final yoga session.
Then the part that matters for practice, stated carefully. The researchers looked at the scan taken after twelve weeks but before that final session, and split participants after the fact by whether their GABA had risen. Those whose GABA was up had last practiced a mean of 3.9 days earlier. Those whose GABA was not up had last practiced a mean of 7.8 days earlier.
Be clear about what the whole study is. There was no control group — the comparison is between two doses of the same intervention, not against no intervention. The design cannot separate the postures from the breathing; the intervention is a bundle. The sample is small and there was no blinded clinician rating of depression. The authors call their own support tentative: the study links yoga to a GABA rise and to improved mood; it does not prove one causes the other.
What it suggests is practical, and it is the same thing the tradition has always said. If GABA is part of how this works, the effect does not bank. It fades in days. Practice at least weekly. Regularity, not dosage, is what the data reward — the lower-dose group is the one whose GABA moved.