Floatation significantly decreases stress, depression, anxiety, and pain, while significantly boosting optimism and sleep quality. A control group received no significant results, demonstrating that floating’s benefits are more than just a placebo effect.

Kjellgren, Anette. “Beneficial effects of treatment with sensory isolation in flotation-tank as a preventive health-care intervention – a randomized controlled pilot trial.” BMC Complementary and Alternative Medicine, Jessica Westman, 14:417, 2014.