Dependency

Why do some people become addicts and some not?

All forms of addiction (and addictive behaviors) and only these ultimately stimulate dopamine release or increase its activity in the nucleus accumbens, the same way electrical current in rats, monkeys, and humans does, and cause dopamine release throughout the brain, and produce the hedonic response . The hedonic responses to these addictors are: I like that, motivation, incentive stimulus, goal directed behaviors. 
Addictors stimulate dopamine release in throughout the brain.
Drugs that block dopamine block this response.
Dopamine coordinates responses throughout the brain, especially the emotional and memory parts of the brain. It provides information about what’s important to the organism a well as feeling of well being.
Dopamine does all this in all people, so why do only some people get addicted and most others don’t? The organisms (animals and humans) that get addicted are the ones that started genetically with low dopamine activity to begin with. This genetics separates people who get addicted and people who don’t. 
It is this low dopamine activity that causes these people to unconsciously seek out dopamine raisers, drugs and behaviors, and get addicted to them, all unconsciously, from the very beginning. This science dispels all other theories of addiction causation: psychological/psychodynamic/psychobabble, free will choice, immorality, and criminality. genetic dopamine deficiency physiology of addiction causation is both necessary and sufficient to explain addiction causation from the initiation of addictor use through addiction through relapse. Prevention and recovery should be derived from this theoretical basis