Chapter 251: Addiction of Prescription and Nonprescription Drugs

INTRODUCTION

Patients with addiction can baffle and overwhelm even the most compassionate physicians, and these patients sometimes even deceive themselves into believing there is no problem. The symptoms of drug and alcohol use can mimic or co-occur with mental illness and chronic pain, complicating the diagnosis. Families can play a role in the development of addiction and also in its treatment. Fortunately, addiction is a treatable disease of the brain. Physicians have a unique opportunity to intervene in the addictive process and shepherd our patients—and our colleagues—into treatment when needed.

The brain is hardwired to reward behaviors that enhance survival of the individual or the species. The reward is pleasure, and it happens when dopamine levels rise in the limbic system. For example, eating when you are hungry, drinking water when you are thirsty, or having sex releases dopamine, which is subjectively experienced as pleasurable. People are motivated to seek pleasure and avoid pain in order to survive. Every behavior you perform is related to pain avoidance or short- or long-term pleasure reward.

Drugs of abuse—including alcohol, nicotine, illicit drugs, and some prescription medications—are potentially dangerous because they raise the dopamine in the limbic system faster, longer, and much higher than any natural reward (such as food, sex, or seeing your family). The brain, which is motivated to seek immediate reward, drives an individual’s behavior to repeat the intense pleasure as much as possible. Dopamine also enhances learning and classical conditioning, so a person with an addiction unconsciously learns the pleasurable “survival value” of the drug. If the drug use continues, it essentially hijacks the brain’s motivational dopamine system, tricking the brain into behaving as though the individual needs the drug to survive. At this point, the individual becomes dominated by seeking and repeating drug use. Changes take place in the brain that make it extremely uncomfortable to be without the drug. Natural dopamine production downregulates, and the brain becomes less responsive to dopamine presence. This is known as tolerance, meaning more of the drug is needed to produce a pleasurable sensation. It also means that previously pleasurable activities are no longer gratifying. The relative absence of dopamine leads to dysphoria in the absence of reinforcing drugs. Taking the drug is the fastest and easiest way for an addicted person in withdrawal to feel “normal” again. Eventually, continuing drug use overwhelms voluntary control and crowds out other relationships, becoming more important than an individual’s family, values, even food and sex. At this point, drug and alcohol users isolate from other people to focus more obsessively on drug use. When addiction progresses to this level, people may use any means necessary—including ...