
No one who begins to use drugs thinks he or she will become addicted. Addiction is a disease characterized by compulsive drug seeking behavior regardless of the consequences.
Research conducted by the National Institute on Drug Abuse shows that virtually all drugs that are abused have a profound effect on the brain. Prolonged use of many drugs including, cocaine, heroin, and amphetamines can change the brain in fundamental and long lasting ways resulting in drug craving addiction.
The brains of addicted people "have been modified by the drug in such a way that absence of the drug makes a signal to their brain that is equivalent to the signal of when you are starving," says National Institute on Drug Abuse Director Dr. Nora Volkow. It is "as if the individual was in a state of deprivation, where taking the drug is indispensable for survival. It's as powerful as that."
Addiction grows more serious over time. Substance use disorders travel along a continuum. This progression can be measured by the amount, frequency and context of a person's substance use. As their illness deepens, addicted people need more alcohol or other drugs. They may use more often, and use in situations they never imagined when they first began to drink or take drugs. The illness becomes harder to treat and the related health problems, such as organ disease, become worse.
Certain risk factors make it more likely that individuals will become addicted to alcohol and other drugs including:
(Source: HBO addiction; the five things you should know about adolescent brain development and use, Thomas J. Crowley, M.D., Elizabeth Whitmore, Ph.D.)
The success of any treatment approach depends on a variety of factors such as the child's temperament and willingness to change, and the extent and frequency of use. Drug addiction is now understood to be a chronic, relapsing disease. It is not surprising, then, that parents may have to make a number of attempts at intervention before their child can remain drug-free, and they should not despair if their first try does not produce long-lasting results. Even if it is not apparent at the time, each step brings the child closer to being healthy.
(Source: Growing Up Drug-Free: A Parent's Guide to Prevention - 1998)