I am very likely either unipolar or bipolar, and am on both an antidepressant and antipsychotic. I know that cycling is definitely therapy. My wife has noticed that I *hate* driving now and will bike whenever possible. My commute sends me to a happy place (endorphin rush) that can last for hours, and not much will do that for me. In fact, a good 30 minute commute home, busting my butt the whole way, sends me into heaven. I absolutely love it. It also saves me from the aggrivation of putting miles on my already ancient car, and having to deal with being stuck in traffic.