Welcome! I've suffered from depression since childhood and though it defintely wasn't caused by diet, I'm sure diet didn't help me get well again.
I've taken antidepressants on and off for 20 years and am almost off them now. I have been primal for almost a year and feel the time is right to come off my medication. So far so good. I'm amazed, but my diet is clean and I'm not poisoned by food or ill health now.
Good luck with your journey, a clean body is definitely a step in the direction for good mental health.
A primal diet was able to get me off of 100mg of daily Zoloft for my anxiety.
When I first went primal, I had been on most of the newer anti depressants at one point or another. None of them ever lasted more than a month before losing effectiveness or making it worse. I originally went primal to help my thyroid, figuring if nothing else, I could lose a few vanity pounds. It has not only allowed me to half my dose of levothyroxine, but effectively "cured" my depression and curtailed my GAD. "Cured" is in quotes because it comes back the instant I go back to CW. I can indulge in a little every once in awhile but, the better I behave, the better I am mentally.