If you want my two cents, being an ex-meth addict, I'll tell you this: if you are trying to 'use' meth as way to help depression, you are staring helpless addiction in the face. It may seem useful at first, but BELIEVE ME, it's not.
I started out using it for depression on weekends, or just sparingly...but after about 2 months, that ended. I realized it's potential for treating my depression, or 'covering it up'; before long I was using it every day. And using meth turns into abusing meth, by its very nature, because you will build a tolerance FAST, and before you know it you're doing it several times a day, in high doses, just to maintain. And then you're up for days/weeks at a time, and the only way to fight the psychosis and suicidal comedown is to do more meth.
It's a downward spiral that I have a soft spot in my heart for, because I completely understand someone's desire to use it for this application; especially majorly depressed individuals. It's a living nightmare that will destroy one's life and will, completely inadvertently; and in most people I've known, it's a nearly impossible struggle to quit, but you just can't because of the absolutely insane psychological addiction.
Tread carefully using amphetamines for depression. After a short time, they will take hold of your soul and chain you up like you never in your worst dreams could have imagined.