I replied earlier in this thread but since it's been a month or two I'll reply again. (This got longer than I had intended, so feel free to skip it if you don't want to read too much.)
I think addicts have some huge gaping hole in their soul that is insatiable in it's appetite to make itself whole yet it is never whole, just a hole.
I notice I'm like that, it's four thirty am where I live and I'm here writing on addiction, if I were normal I'd be sleeping, but instead I took some adderall and have been up all night practicing music and doing random things on the internet. There's some compulsive factor at work behind all this.
I did have the opportunity to smoke some Heroin for free today and I hadn't had any sub for almost two days but I turned it down because I had a broken headlight and I would have had to drive shortly afterwards, so I'm still capable of making rational decisions when chemicals that I love are thrown in front of me.
I think some addicts are perfectionists who continually get in their own way, but basically nothing is ever good enough, it can always be better and we are never satisfied.
I know I personally have suffered through some undiagnosed mental disorders that led me to my addictions, I don't know what would have happened had they been treated earlier. But I was always addicted to adrenaline rush type of activities, be it skateboarding or jumping off the biggest cliff I could find into the ocean with my friends when I was a kid.
I had a good childhood so I can't blame my addictive personality on that, but there is the subject of genetics which is interesting. My sister is the exact opposite of me but she is ever bit as much of an addict, she constantly counts calories, is always running and terrified of gaining weight, struggles with eating disorders. She's also obsessed with being completely on top of her finances down to the last cent every single minute. She never really got into drugs, but I gave her an ambien once and she went out and got a prescription within a week, she's also on antidepressants, she's addicted to being in control which I think all addicts are to some degree, but she goes about it in the opposite way as I do.
I chose to become a professional musician, sometimes it seems like it chose me actually (talk about a career path to addiction!) my finances are a mess, I take too many drugs, there is no security in my life but I get to do what I love every day and night and you can bet I'm addicted to that, it almost seems like the more chaotic my life is the better any given performance is because it's a way for me to escape, I feel very free when I'm playing. It is extremely cathartic and boosts my adrenaline levels like crazy. This was part of my beginning of my drug use, music got me so high that I never wanted to come down after I was done.
To continue on the genetic theory, my mom is plagued with anxiety and depression but she handles it without resorting to the addictive ways my sister and I have. My dad is a classic case of untreated ADD, dreams big, has brilliant ideas but never ties up the details so his finances are always up and down, he refuses to work for anyone but himself. This frustrates the hell out of my mom, but in spite of all that they are relatively normal.
I could go on and on, we're all different but we still have that addict thing happening. It's fascinating to me but it also scares me because it's taken me to some not so pretty places and destroyed some very beautiful situations in my life.
I'm interested in hearing other peoples definitions.