I'm going to say that, for me, it was amphetamines (adderall), and I know that may surprise some of you, but hear me out...
I was a twenty-one year old college student and an education major to boot when I began taking adderall. I had a lot of work to do, a lot of lesson plans to write, unit plans and whatever else, and I always worked part-time jobs on top of everything else. In other words, man, I had a lot of shit that needed to get done.
I began taking adderall, and suddenly, I felt like the most capable and intelligent person in the world. I'd bang out a dozen lesson plans, write a couple papers, go to work, bang out another dozen lesson plans, go to my field assignment, come home, write some more papers... you see where this is going. I mean, I didn't need to sleep anymore or eat anymore and I become one unbelievable work-horse, and it felt so, so good. I felt more capable and more intelligent than anyone else. I became less depressed, and everything was great, until I tried to quit taking adderall...
It's not like after taking adderall you go back to feeling normal; you don't. I didn't know this, but I soon found out when I became even more depressed than before, even more unmotivated than before, sluggish, tired, and all-around just feeling shitty. I can't even describe it accurately enough because the experience was just so nightmarish.
The only solution, of course, is to continue taking the adderall. So, I'd quit taking it for a few days, but I'd soon be right back on it once I couldn't take it anymore. (I finally did kick it, but it took months and months and months for me to begin feeling normal again.)
It's just one huge mind-fuck, man, because you can't remember what it feels like to not be so amped up all the time. You feel like there's that thing missing, your spark is gone, you aren't the same as you were before, and you need to continue taking the adderall to feel normal.
Yeah, I can honestly say that, for me, adderall is it. I love opiates, but when I quit sniffing dope, I just feel physically ill for a few days. I might crave it a little bit, but in a few weeks time, all of that goes away. Not so with adderall... lasts months, man, and it's not so much physical as mental.