Does GABA improve sleep and mental health? Original paper

In this randomized controlled trial in participants with a sedentary lifestyle and overweight or obesity, supplementing with GABA had little effect on sleep metrics and measures of mental health.

Whether supplementing with GABA improves sleep and mental health.

The outcomes assessed were sleep quality, heart rate variability (HRV), stress, anxiety, depression, positive affect (mood), and negative affect.

30 women (average age of 44) with a sedentary lifestyle and overweight or obesity.

In this 90-day randomized controlled trial, the participants took either 200 milligrams of GABA or a placebo 30 minutes before bedtime daily. In both groups, the participants performed three 50-minute workouts per week that included aerobic exercise and resistance exercise.

Sleep quality was assessed using the Pittsburgh Sleep Quality Index, which considers 7 different dimensions of sleep (e.g., sleep latency, sleep duration, sleep efficiency). HRV was assessed at rest, during a progressive treadmill test, and after the treadmill test. Mental health was assessed using different questionnaires.

Compared to the placebo group, HRV increased (improved) after exercise in the GABA group. Also, sleep efficiency was better in the GABA group than the placebo group at the end of the study. There were no other differences between groups.

Although there were no significant differences between groups, compared to baseline, depression symptoms improved in both groups, negative affect (mood) improved in the GABA group, and stress improved in the placebo group, suggesting that regular exercise can improve mental health in people with a sedentary lifestyle.

Because the participants, on average, had mild to moderate symptoms of stress, anxiety, and/or depression at baseline and were not required to have poor sleep quality at baseline to be entered into the study, there may have been limited room for improvement in the assessed outcomes. As such, the results may not be generalizable to other populations.