pretty remarkably hold it together in spite of drug use that is out-of-control, so called “Functional addicts”. But eventually, they will succumb to the consequences of drug use.
2. Tolerance: increasingly more drug required to get the same effect. The body tries in many ways to minimize the effects of the continuous exposure to the drug. This is a defense by the body but for the addict, they are still trying to reach the desired effect. So more drug is needed to overcome the body’s defenses and achieve the “high” the addict craves.
3. Withdrawal. As mentioned above, your body attempts to counteract the effects that a drug produces by activating opposite effects. For example, continuous exposure to a depressant like alcohol will drive the nervous system to activate stimulatory systems to counteract the depression on the brain. This tug-of-war between the drug and the body’s defense result’s in a sort of “truce”. The body has adapted to the continuous effect of the drug and counteracted it. Now, if the drug is abruptly removed, the brain is thrown off balance because the stimulatory actions that were protective no longer have any alcohol to work against. Now the body is in a hyper-agitated state that can actually be very dangerous. This very uncomfortable state forces the person to seek more drug and reestablish the balance.
So how does one get addicted in the first place? Most drugs activate pleasure centers in our brain. Our brain has a reward system that encourages behaviors that increase individual survival and perpetuation of the species. When you eat your favorite food, usually high in fat and sugar, the pleasure centers are activated. This is because, in nature, the consumption of high caloric foods provides a survival benefit because access to food is often unpredictable. Sex also activates pleasure centers (did I need to say that?) and without sex, a species becomes extinct (very little chance of that with 7 billion+ humans on the planet).
The euphoria and intense feeling many recreational drugs produce are linked to these pleasure pathways. The nerves involved in these pathways release the chemical dopamine. This neural chemical dopamine drives the