For good measure, magnesium supplementation daily might not be a bad idea after such a long period of amphetamine abuse. It can help in exerting calming effect and hypnotic effect, too. This might just allow you to "regulate" your mood a bit better. Melatonin at nighttime is also a pretty good idea, with some findings which have led me to speculate that it is neuroprotective. It also leads to better sleep, sleep being crucial for health, and I imagine after four years of amphetamine abuse, sleep patterns will be changing. These two supplements could somewhat indirectly help your symptoms, but it might take time. Still, it would be worth a shot in my mind. As for orthodox anti-depressants, I am not sure what to say after such a period of amphetamine abuse. I don't know if some are better than none for you right now and will help you in the long run, too? I am not really a fan of such anti-depressants, as they do screw with neurochemistry in some pretty "drastic" ways. They can help, of course, but after the amphetamine-induced changes in neurochemistry I wouldn't feel right suggesting going off of them or changing them or staying on them - so I don't have much advice there. I wonder if your current state will improve with time on the med regimen you are on now, or if it would be better with others (or maybe to switch down the line), or maybe none. Like I said, I really can't advise this or that in a black and white sort of way. Just keep in mind, amphetamines are neurotoxic - so allow your brain to get healthier just from the effects the amphetamines have caused (does not mean go off current psych meds). I do still suggest magnesium and melatonin, both being of more benefit than what you might think. I will think on this topic more, and may write another response if I come up with an idea as for a more orthodox anti-depressant option.