The Disease Model
According to the disease model of addiction, addiction is a brain disease. Marked changes in brain structure and function that, over time, lead to involuntary use or compulsive behavior are the key characteristics of the disease (Leshner, 2001). The behavioral expressions of addiction are uncontrollable, and in that aspect, similar to that of other brain diseases. For example, just as schizophrenics cannot voluntarily control their hallucinations and delusions or Parkinson’s patients cannot control their trembling, an addict cannot control the urge to use (Leshner, 2001). Once an individual has the disease, it is irreversible. It is an incurable, chronic illness. Proponents of this model purport treating the addict just as one would treat an individual with any other brain disease or chronic illness (McLellan, Lewis, O’Brien & Klecher, 2000). As with other diseases, a holistic treatment approach, combining medication therapy, behavioral therapy and any needed social services and rehabilitation is considered the best treatment approach (Leshner, 2001).
Research would seem to support the position that chronic substance use produces long-lasting changes in the brain (Volkow, Chang, Gene-Jack, Fowler et al., 2001) that are responsible for the impaired cognitive functioning, including the compulsive urge to use, that is characteristic of addictive behavior (Leshner, 2001). The comparative analysis conducted by McLellan and others (2000) also suggests similar kinds of factors, including genetics, contribute to addiction and other chronic illnesses, such as diabetes and hypertension. They also found that drug dependence shared several other features with chronic illnesses, such as treatment compliance and relapse (McLellan, 2000). While this does not offer definitive proof that addiction is a chronic illness, it does lend some credibility to the theory.