I actually never got around to going to a dermatologist to get it - as annoying as breakouts are, my skin has gotten much better since I started exercising again, stopped eating refined sugar and I switched to a different cleanser...
That being said, one of my coworkers is on it, she hasn't had a problem with the depression or anything associated with it like that. She said that it *can* make you more dehydrated - some people experience dry skin and the need to constantly have lip balm around.
I know that she would not have recommended it to me if she had experienced any of those side effects. If you have a history of depression, I would talk to my doctor about that, and I would probably ask them if they thought that there was any issue with a low carb diet and taking it. Then again, I also look at the package insert of any drug that I think about taking, and it's available online for Accutane...
P.S. Tea tree oil can help (I have used that before)- don't use it all over your skin, it can cause dryness as well, don't use on any open cuts, and it smells kinda funny.
If you want to try out a couple cleansers (not sure if they'll help you or not), LUSH has a soap called "Fresh Farmacy" that helped, and L'Occitane has a new Rice cleanser (and moisturizer) for problem skin - which is what I currently use.