There is a correlation between mental illness/mood disorders and vegetarianism. It's important to remember that correlation does not imply causation.

Since I was a child, I've had a strong adversion to meat. I go long periods without being able to stomach it. However I'm not a vegetarian. Sometimes I will eat it. Nothing with bones or off a carcass.

My eating habits are all over the place. I go long periods eating very healthy and well. I also go long periods overeating and eating terrible foods. And often I enter phases where the thought of food makes me sick and I have to force myself to eat, even though everything tastes and feels like the equivalent of sawdust.