The New Science of Drug Abuse
Within the past five years or so, scientists have come up with a new theory of drug dependency that may explain why some people are more susceptible to drug abuse, and why most people have trouble stopping drugs without professional interventions. Most recently, scientists have been using brain-imaging technology such as magnetic resonance imaging to study drug addiction. These new tools enable researchers to actually view the changes drugs produce within different parts of the human brain and in brain chemistry. Scientists are just beginning to launch longitudinal studies that will dramatically increase their knowledge of the long-term effects of drug abuse.
What science is discovering through this new technology is that the human body produces a chemical or neurotransmitter called dopamine. When a person is in pain or under stress, dopamine levels rise to alleviate the situation. When he feels pleasure or experiences beauty, dopamine levels also rise. The problem is that nearly every drug of abuse, including nicotine, marijuana, cocaine, heroin, and methamphetamine,
increases dopamine levels too.
The new brain imaging technology shows that drugs bind themselves to brain receptors and activate pleasure circuitry in the brain, which artificially elevates dopamine levels. Over time, abusing drugs changes the way a person experiences pleasure and reward. Instead of seeking pleasure from accomplishment, beauty, love, and other normal outlets, the drug abuser learns to seek feelings of pleasure and increased dopamine levels artificially from drugs.
Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, explained it this way when she testified before Congress, “Addiction results from the repeated perturbation of reward circuits. There comes a point, where an individual’s brain becomes so altered that normal rewards are no longer sufficient, judgment and decision-making circuits become impaired, and the individual’s overriding motivation becomes seeking and taking drugs.”
At that point, the person is physically addicted to drugs. His behaviors, thoughts, and motivation become about seeking and using drugs. Just as diabetes is a chronic physical condition due to irregularities in blood sugar levels, drug addiction is a chronic physical disease due to alternations in brain chemistry.
Scientists have also discovered why some people are more susceptible to abusing drugs. Again, using the new brain imaging technology, scientists find that some people have lower than the average number of brain receptors for dopamine. They experience drugs like cocaine and heroin as pure and exalted pleasure. On the other hand, people with the normal numbers of receptors experience the same drugs as deeply unpleasant.
Scientists are also beginning to understand why most drug addiction and alcoholism have their start in the teen years. The part of the brain that evaluates situations and looks at long-range consequences of decisions is not fully developed until age 25, but the part of the brain that encourages risk-taking and dare devil activities is in full force during adolescence. This means that teenagers are more likely to experiment with drugs and alcohol without considering their long-term effects or risks such as addiction, increased chances for automobile accidents, contracting sexually transmitted diseases, etc.
The new research is revealing that drug addiction is a chronic disease like diabetes, asthma, or hypertension. It has an onset, a course of medical treatment, and an outcome. Drug addiction treatment is every bit as effective as treatments for diabetes, asthma, hypertension, or any other chronic disease. Drug addiction is a no-fault disease that can be successfully treated.