right brain left brain

I have dealt with depression all my life until just recently. I am now conviced that mental illness is due to a physical cause. It has to do with communication between the right and left brain.

actually depression does have symptoms and causes in the physical world although it is hard to distinguish between the two.
however, when the left and right hemispheres don't communicate well it is not called depression. most often it is epilepsy. the medications for epilepsy and depression are different. but you never know what an anticonvulsant is used for. when i was a teen i was misdiagnosed as a petit mal epileptic, so i know a little about both diseases.
the real question isn't cause in my opinion but instead trying to do something good with your life in spite of handicaps. treatment will be the same no matter what the cause is. you can't treat your life as a cautionary tale--a bad example to others based on this or that cause. good luck with that
-pi

I think that it is caused by how you developed due to an environment that wasn't the best for you or didn't respond to you in a very good way. You only know what you learn and you learn from your experiences in your environment.

exercising both left and right sides of my body has decreased my depression

exercise helps lift up a lot of pople for a lot of reasons. some of them are neurochemical like the production of endorphins by the body when it is exercised. the increase in metabolism can also lift you partly out of depression and help you with your weight--something i definitely need.
but this isn't a left side of body // right side of body issue unless we are talking about a stroke patient and i don't think we are.
-pi

i guess for me it was about building self confidence also.. exercising each side of my body gave me added body awareness.. with that, i felt more capable of doing the physical projects in my life.. that confidence gave me the positive attitude i needed to do a great deal more in my life.. confidence building is one way to end depression... compassion for others also helps a lot.. when we want support its a lesson we learn in life, that if we give, we might receive..

body awareness is good. i tried taking group yoga classes for that a few years ago. for whatever reason my instructor did want men in the class but she had advertised in the town park and recreation newsletter so she couldnt just throw me out. it took her a month to drive me away.
i should try yoga again sometime but i am so heavy now that i might injure myself doing that.
pi