The Baffling Connection Between Vegetarianism and Depression

Baffling Connection Between Vegetarianism and Depression
  • In a 2010 study published in Nutrition Journal, Arizona State University investigators found that Seventh Day Adventists who were vegetarians had lower depression, anxiety, and stress scores than meat-eating Adventists. (Here is the full text.)

The Problem with “Link-Think”

You have to be careful about link-think. Take the link between animal cruelty and human-directed violence.

Contrary to conventional wisdom, this link is surprisingly weak. Most kids who abuse animals become normal adults and most serial killers and school shooters do not have a history of animal abuse. (See Animal Cruelty Does Not Predict Who Will Be a School Shooter).

Similarly, only a small fraction of people who suffer from depression are vegetarians and most vegetarians are not depressed. However, the existence of multiple studies involving thousands of subjects by researchers in different countries suggests that the connection between vegetarianism and depression is not a statistical fluke.

Read Frequent Anger and Irritability Could Signal Depression, Research Reveals

Does Vegetarianism Cause Depression?

What is going on?

I can think of a couple of possibilities.

First, it could be the case that vegetarian diets actually produce biological changes in brain chemistry, or even the microbiome, that causes some people to be depressed. I am a bit skeptical of this explanation, but the German study mentioned above found that 34 percent of people with depression started on a vegetarian diet before the onset of their mental disorders, compared to 9 percent of people with anxiety disorders.

I think it is more likely that some traits may predispose some people to both depression and to vegetarianism. Women, for example, are twice as likely as men to suffer from depression, and there are also more female vegetarians than male vegetarians.

And, while the evidence is mixed, some personality types may also be particularly drawn to vegetarianism.

In addition, vegetarian diets can be isolating. A woman who recently became a vegan told me that she suddenly gets fewer dinner invitations from old friends: They don’t know how to cook for her. And one young woman told me, “I won’t go out with anyone who is not a vegetarian. It limits my pool of possible men.”

Read 5 Lies I Believed About Depression

Further, social reasons rank high when former vegetarians and vegans are asked why they returned to meat. (See Why Do Most Vegetarians Go Back To Eating Meat?)

Finally, as several animal activists pointed out to me after this post was initially written, the vegetarian-depression link could be the result of moral commitment. As Lori Marino, executive director of the Kimmela Center for Animal Advocacy wrote on Facebook, vegetarians and vegans are more aware of the cruelties of the world and this is more depressing than living in a state of ignorant bliss.

Lori is right. Indeed, the emotional and psychological costs of devoting your life to animal protection was a major theme in one of my first studies of human-animal relationships. (Full text here.)

In short, we don’t know why the rates of depression seem substantially higher among vegetarians than in omnivores. But we do know that “correlation does not imply causality” and “more research is needed.”

Written by Hal Herzog
Originally appeared in Animal and Us Blog on PsychologyToday


  • Baines, S., Powers, J., & Brown, W. J. (2007). How does the health and well-being of young Australian vegetarian and semi-vegetarian women compare with non-vegetarians? Public health nutrition, 10(5), 436-442.
  • Beezhold, B. L., Johnston, C. S., & Daigle, D. R. (2010). Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults. Nutrition journal, 9(1), 26.
  • Burkert, N. T., Muckenhuber, J., Großschädl, F., Rásky, E., & Freidl, W. (2014). Nutrition and health–the association between eating behavior and various health parameters: a matched sample study. PloS One, 9(2), e88278
  • Forestell, C. A., & Nezlek, J. B. (2018). Vegetarianism, depression, and the five factor model of personality. Ecology of food and nutrition, 57(3), 246-259.
  • Hibbeln, J. R., Northstone, K., Evans, J., & Golding, J. (2018). Vegetarian diets and depressive symptoms among men. Journal of affective disorders, 225, 13-17.
  • Jacka, F. N., Pasco, J. A., Williams, L. J., Mann, N., Hodge, A., Brazionis, L., & Berk, M. (2012). Red meat consumption and mood and anxiety disorders. Psychotherapy andpsychosomatics, 81(3), 196-198.
  • Meesters, A. N., Maukonen, M., Partonen, T., Männistö, S., Gordijn, M. C., & Meesters, Y. (2016). Is there a relationship between vegetarianism and seasonal affective disorder? A pilot study. Neuropsychobiology, 74(4), 202-206.
  • Michalak, J., Zhang, X. C., & Jacobi, F. (2012). Vegetarian diet and mental disorders: results from a representative community survey. International Journal of Behavioral Nutrition and Physical Activity, 9(1), 67.
  • Rosenfeld, D. L. (2018). The psychology of vegetarianism: Recent advances and future directions. Appetite 131: 125-138
  • Timko, C. A., Hormes, J. M., & Chubski, J. (2012). Will the real vegetarian please stand up? An investigation of dietary restraint and eating disorder symptoms in vegetarians versus non-vegetarians. Appetite, 58(3), 982-990.
The Strange Link Between Vegetarianism and Depression
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The Baffling Connection Between Vegetarianism and Depression
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Hal Herzog Ph.D.

Hal Herzog has been investigating the complex psychology of our interactions with other species for more than two decades. He is particularly interested in how people negotiate real-world ethical dilemmas, and he has studied animal activists, cockfighters, animal researchers, and circus animal trainers. An award-winning teacher and researcher, he has written more than 100 articles and book chapters. His research has been published in journals such as Science, The American Psychologist, The Journal of the Royal Society, The American Scholar, New Scientist, Anthrozo's, BioScience, The Journal of the American Veterinary Medical Association, and Animal Behavior. His work has been covered by Newsweek, Slate, Salon, National Public Radio, Scientific American, USA Today, The Washington Post, The Boston Globe, The Chicago Tribune and many other newspapers. In 2013, he was given the Distinguished Scholar Award by the International Society for Anthrozoology.View Author posts