Advances in neuroimaging – pictures of the brain – have allowed researchers to look inside the brains of people with addiction. They can see, in real-time, what makes a person addicted to a substance like drugs or alcohol. The brain’s reward system – based largely on dopamine – thirsts for more of the addictive substance. The centers of the brain that control such desires have, essentially, a system failure.
The pattern is similar with many kinds of addictive behaviors. Altering the machinery of the brain is the real challenge in conquering an addiction. Drugs and addictive behaviors "hijack" the reward system, according to Dr. Petros Levounis, director of the Addiction Institute of New York at St. Luke’s and Roosevelt Hospitals in Manhattan. Dopamine plays a crucial role in motivation and reward, increasing before and during a pleasurable activity, like drinking or taking drugs. This makes people want to continually repeat the behavior.
Dopaminergic pathways connect the limbic system, which is responsible for emotion, with the hippocampus, which is responsible for memory. This combination makes rewarding behaviors associated with strong memories. The problem of addiction rears its ugly head when the memory and the craving dominate a person’s life. Normal function in the frontal lobes of the brain, responsible for willpower, often decreases in addicts.
"Ultimately, the war on drugs is a war between the hijacked pleasure reward pathways that push the person to want to use, and the frontal lobes, which try to keep the beast at bay. That is the essence of addiction," said Dr. Levounis.
