Studies have shown that prolonged drug abuse can actually alter the physical and chemical structures of the brain, and even produce a brain disorder, called addiction or dependence. Drug addiction is distinguished by a pathological longing for drugs to the point where a want becomes a need. Seeking out drugs and taking drugs evolve into activities that take up a large amount of an addict’s time and thoughts, most often at the expense of other daily life activities. Even though these types of behavior produce many adverse consequences, an individual who is addicted is perhaps most defined by their inability to stop, even if they want to stop.
Why can’t they stop?
Scientists have found that almost every abused drug whose use results in pleasure activates the brain’s reward system. They act as a shortcut straight to this reward system by firing a large amount of dopamine into the nucleus accumbens, a region of the brain involved in processing pleasure, motivation, and reward. This area evolved to differentiate between the effects of rewards such as eating when hungry or drinking when thirsty. When pleasure is produced because of these actions, we learn to repeat the ones that gave us the pleasurable reward. Addictive drugs falsely activate this system, and we are hardwired to seek out the pleasures they deliver.
In addition to activating the brain’s reward system, abused drugs are also capable of altering the parts of the brain involved in judgment and executive functions of higher-level thinking such as decision-making, planning, and inhibiting inappropriate behaviors.
Why do some people get addicted?
Even though researchers aren’t entirely sure why some people become addicted and others do not, they suspect it may have something to do with a potential addict’s inherent deficiency of dopamine supplies within their brain. They also suspect that they have more vulnerable reward systems, more intense responses to stress, and more likely to suffer from depression, antisocial personality, anxiety, and schizophrenia.
Perhaps it has something to do with a deficiency in the operation of the prefrontal cortex. Many addicts become so during adolescence, when that area is not fully developed. One of the functions of the prefrontal cortex is to diminish our urge to take a drug when it would otherwise be unwise.
Even though progress is slow on understanding the differences in the brains of addicts versus non-addicts, the good news is that with a better understanding comes more efficient ways of helping addicts into recovery.