Virtually no one wakes up one morning and says to himself, "What a beautiful day! I think I'll get addicted to drugs today!" However, a huge number of people end up addicted to a variety of drugs. (Alcohol is a drug, too, but that's another page.) How does this happen?
Any substance which alters a bodily function is, technically, a drug. However, the drugs which we are concerned about here are drugs which alter the functioning of the Central Nervous System (CNS). Any drug which either depresses (slows down) or stimulates (speeds up) parts of the CNS has the potential for addiction.
Addiction involves several processes which take place over time. First, the drug must be taken. Then, the effects of the drug are experienced. If the effects of the drug are pleasurable, brains learn very quickly what to make the body do, in order to get the experience of being "high" again. So, the brain learns to seek out the drug experience.
As the drug is taken more regularly, subtle changes happen in the chemistry and architecture of the brain. Because of the way nerve impulses are transmitted, and the fact that the brain is set up to try to maintain a balance of the chemicals in it, when a drug floods the chemical sensors in the CNS it becomes less sensitive to the drug, and also less sensitive to the brain's own chemicals (which the drug imitates). So - the end effect of taking the drug is that the brain needs more and more of the drug as it becomes less sensitive to it. This is called the development of tolerance to the drug.
Also, a withdrawal effect becomes noticeable. Withdrawal is caused by the development of tolerance to the drug combined with the absence of the drug (which the brain now expects to be there). A common example of a withdrawal reaction is a hangover from drinking alcohol. The increased sensitivity to noise and light, and the headache, are the opposite of the effects of the alcohol (alcohol causes things not to bother you), which dilates blood vessels and then wears off, causing blood vessels to constrict again.
Addiction becomes a problem when the desire to use the drug, efforts to get it, activities related to using it, and relationships associated with using it grow in importance and eventually assume a central role in the person's life. Addicts come to believe that their responsibilities are interfering with their use of the drug, while everyone else sees it the other way.
There are a variety of ways that addicts manage to continue using - mostly they involve exploiting others in one way or another. Many of the 2,000 or so addicts I have worked with over the years have said something to the effect that, "I can't tell you how I maintained a $2,000 a month habit on a $1,500 a month salary, but I did." The deception and disappointment which the addict creates only serves to alienate him from his family and friends, and often by the time he gets to treatment he has virtually no support system.
Although denial among addicts is as powerful as that among alcoholics, the rapidly escalating nature of drug addiction is such that in many cases it only takes 6 months or a year for the addict to experience negative consequences due to his using; whereas the alcoholic can often drink heavily for years without having any serious consequences.
If you believe that you, or someone you love, has a problem with drugs, you owe it to yourself to get help, either through one of the Anonymous Programs or through a trained professional such as a psychologist with experience in the area of substance abuse. A brief assessment can either put your mind at ease, or verify that there is a problem and plot a course for dealing with the problem.
Sometimes, a Family Intervention (a well-planned, loving confrontation of the addict to get him to seek help) can work wonders. Ask your psychologist, or local chapter of the National Council on Alcoholism, for information or referral to an intervention specialist.