Mental Health

[ Because this page is separated into separate sections for meta-analysis/reviews and individual studies, I'm ignoring my typical custom of coloring evidence from then. ]

Lots of research has been done on happiness/well-being, and much of it is centered around correlation rather than causation. If you care about that, you can read about it elsewhere Well-being contributing factors, but I'm focusing only on causal factors here.

See also Muelhauser.

Exercise RCT Meta-Analyses & Reviews

  • Acute exercise has an immediate moderate effect on short-term and long-term memory, while long-term exercise had small and insignificant effects, respectively Roig.
  • Aerobic exercise lasting 21-30 minutes reduces anxiety (d=0.41) for at least half an hour post-exercise with no sign it disappears after that Petruzzello. Moreover, these effects grow over the first several weeks and anaerobic exercise generally lacked this.
  • Both cardio and resistance training improve mood (d=0.69), but should be done only 1-2 times per week for this purpose. Effects shrink over time Arent
  • Exercise also improves on 8 of 10 psychological measures examined in Netz, especially self-efficacy (d=0.38) and overall well-being (d=0.30). Strength training had positive effects, but they were generally smaller than cardio's (d=0.16 vs 0.26).
  • Aerobic exercise also boosts positive affect (d=0.45) Reed
  • Tai Chi reduces stress (d=0.66), anxiety (d=0.66), depression (d=0.56), while improving mood (d=0.45) Tai Chi on psychological well-being: systematic review and meta-analysis. Another meta-analysis found similar results The effects of tai chi on depression, anxiety, and psychological well-being: a systematic review and meta-analysis.
  • Exercise reduced anxiety (d=0.48 Wipfli.

Other RCT Meta-Analyses & Reviews

  • Meditation improves anxiety (d=0.22), depression (d=0.23), pain Goyal and more generally on emotional and relationship measurers, but not much on cognitive measures Sedlmeier. Moreover, when compared to generic relaxation techniques, most of these effects remain, suggesting meditation is doing more than just relaxing people (or at least it relaxes them exceptionally well). Like exercise, the positive effects grow during the first several weeks. Meditation improves sleep quality, but other techniques are comparable Rusch. Unfortunately, I could not find an analysis for how long (in minutes/hours) to meditate for most metrics. The exception is sleep, where they examined 3-42 hours of meditation and found no dose-response. One study found that meditation reduces stress even if done immediately after exercise (at least in the short-term) Bahrke See also Luberto.
  • Positive psychology interventions improve mental health along several measures (d~0.3) Sin, Bolier


  • A famous study from 1978 found that lottery winners were no happier than their demographics would have predicted Brickman, but a later study found the opposite: that winning the lottery does, in fact, make you happier, even 2 years later Gardner.
Wikipedia contributors. (2020, June 21). Well-being contributing factors. In Wikipedia, The Free Encyclopedia. Retrieved 16:36, June 27, 2020, from Muelhauser, L. (2011). How to Be Happy. Less Wrong. Roig, M., Nordbrandt, S., Geertsen, S. S., & Nielsen, J. B. (2013). The effects of cardiovascular exercise on human memory: a review with meta-analysis. Neuroscience & Biobehavioral Reviews, 37(8), 1645-1666. Petruzzello, S. J., Landers, D. M., Hatfield, B. D., Kubitz, K. A., & Salazar, W. (1991). A meta-analysis on the anxiety-reducing effects of acute and chronic exercise. Sports medicine, 11(3), 143-182. Arent, S. M., Landers, D. M., & Etnier, J. L. (2000). The effects of exercise on mood in older adults: A meta-analytic review. Journal of Aging and physical Activity, 8(4), 407-430. Netz, Y., Wu, M. J., Becker, B. J., & Tenenbaum, G. (2005). Physical activity and psychological well-being in advanced age: a meta-analysis of intervention studies. Psychology and aging, 20(2), 272.. Reed, J., & Buck, S. (2009). The effect of regular aerobic exercise on positive-activated affect: A meta-analysis. Psychology of Sport and Exercise, 10(6), 581-594. Wang, C., Bannuru, R., Ramel, J., Kupelnick, B., Scott, T., & Schmid, C. H. (2010). Tai Chi on psychological well-being: systematic review and meta-analysis. BMC complementary and alternative medicine, 10(1), 23. Wang, F., Lee, E. K. O., Wu, T., Benson, H., Fricchione, G., Wang, W., & Yeung, A. S. (2014). The effects of tai chi on depression, anxiety, and psychological well-being: a systematic review and meta-analysis. International journal of behavioral medicine, 21(4), 605-617. Goyal, M., Singh, S., Sibinga, E. M., Gould, N. F., Rowland-Seymour, A., Sharma, R., ... & Ranasinghe, P. D. (2014). Meditation programs for psychological stress and well-being: a systematic review and meta-analysis. JAMA internal medicine, 174(3), 357-368. Sedlmeier, P., Eberth, J., Schwarz, M., Zimmermann, D., Haarig, F., Jaeger, S., & Kunze, S. (2012). The psychological effects of meditation: a meta-analysis. Psychological bulletin, 138(6), 1139. Sin, N. L., & Lyubomirsky, S. (2009). Enhancing well‐being and alleviating depressive symptoms with positive psychology interventions: A practice‐friendly meta‐analysis. Journal of clinical psychology, 65(5), 467-487. Bolier, L., Haverman, M., Westerhof, G. J., Riper, H., Smit, F., & Bohlmeijer, E. (2013). Positive psychology interventions: a meta-analysis of randomized controlled studies. BMC public health, 13(1), 119. Brickman, P., Coates, D., & Janoff-Bulman, R. (1978). Lottery winners and accident victims: Is happiness relative?. Journal of personality and social psychology, 36(8), 917. Gardner, J., & Oswald, A. J. (2007). Money and mental wellbeing: A longitudinal study of medium-sized lottery wins. Journal of health economics, 26(1), 49-60. Rusch, H. L., Rosario, M., Levison, L. M., Olivera, A., Livingston, W. S., Wu, T., & Gill, J. M. (2019). The effect of mindfulness meditation on sleep quality: a systematic review and meta-analysis of randomized controlled trials. Annals of the New York Academy of Sciences, 1445(1), 5. Wipfli, B. M., Rethorst, C. D., & Landers, D. M. (2008). The anxiolytic effects of exercise: a meta-analysis of randomized trials and dose–response analysis. Journal of Sport and Exercise Psychology, 30(4), 392-410. Luberto, C. M., Shinday, N., Song, R., Philpotts, L. L., Park, E. R., Fricchione, G. L., & Yeh, G. Y. (2018). A systematic review and meta-analysis of the effects of meditation on empathy, compassion, and prosocial behaviors. Mindfulness, 9(3), 708-724. Bahrke, M. S., & Morgan, W. P. (1978). Anxiety reduction following exercise and meditation. Cognitive therapy and research, 2(4), 323-333.