Using imaging technology to measure metabolism (in this case, glucose uptake) in the brain and heart, one can see that both addiction and heart disease produce observable changes in organ function. In each pair of images shown above, the healthy organ shows greater activity (reds and yellows) than the diseased organ. In drug addiction, the frontal cortex, which is a part of the brain associated with judgment and decision-making, is significantly affected. Like heart disease, drug addiction can be prevented and treated successfully. If left untreated, however, its effects can last a lifetime.
As a result of scientific research, we know that addiction is a disease that affects both brain and behavior.