New York Times
September 30, 2003

Addiction: A Brain Ailment, Not a Moral Lapse

By JANE E. BRODY
http://www.nytimes.com/2003/09/30/health/30BROD.html

For all that has been written and spoken about addiction as a medical disease, most people, including most physicians, understand little about what draws people to drugs and keeps them hooked, often despite severe consequences and repeated attempts to quit.

A better understanding of the pull and tug of addiction can help those who are hooked and those who want the monkey off their backs for good.

The savings in life-years, quality of life and lost income can be huge, not to mention the costs of drug-instigated crime and medical care.

According to the National Institute on Drug Abuse, $133 billion a year is spent just on treating the short-term and long-term medical complications of addiction. Among the many health consequences of addictions are sudden cardiac arrest, irreversible kidney and liver damage, AIDS, fetal harm and many cancers, including cancers of the lung, bladder, breast, pancreas, larynx, liver and oral cavity.

That it is possible to become free of addictions and remain so is unquestioned.

Seeking Definitions

The nature of addiction is the same no matter whether the drug is cocaine, heroin, alcohol, marijuana, amphetamines or nicotine. Yes, whether they know it or not, chronic cigarette smokers and users of chewing tobacco are addicts.

Every addictive substance, according to a report this month in The New England Journal of Medicine, induces pleasant states or relieves distress.

Furthermore, the authors of the report, Dr. Jordi Cami and Dr. Magi Farré of Barcelona wrote, "Continued use induces adaptive changes in the central nervous system that lead to tolerance, physical dependence, sensitization, craving and relapse."

In other words, addiction is a brain disease, not a moral failing or behavior problem. People do not deliberately set out to become addicts. Rather, for any number of reasons - like wanting to be part of the crowd or seeking relief from intense emotional or physical pain - people may start using a substance and soon find themselves unable to stop.

Of course, not everyone who smokes a cigarette, be it tobacco or marijuana, takes a drink, snorts cocaine or self-injects morphine is destined to become an addict.

Most drinkers, for example, know when to stop before they become intoxicated or tolerant to large amounts of alcohol.

Many people do not like the sensation of losing control and having their feelings and actions determined by a drug. Others refrain from taking the chance that trying a potentially addictive substance will lead to dependence and, so, never take a drink, a puff or a snort or swallow pills or inject a substance that is not medically indicated. Still others may be protected by their genes. Most Asians, for example, carry a gene that makes them physically ill and flushed before they can consume an addicting amount of alcohol.

But genes can work two ways. The risk of addiction can be inherited. The genetics of alcoholism have been well studied, and heredity accounts for about 40 percent of the risk, though it is unclear whether what is inherited is an underlying emotional disorder that drives people to seek relief or a particular physiological reaction to addictive substances that gets them easily hooked.

Dr. Nora D. Volkow, director of the drug abuse institute, told a conference on drug dependency in June that she had never met a patient who wanted to be an addict.

"Sure," she said, "they start out wanting to take a drug. But the problem is we don't know who will become addicted."

According to the Institute of Medicine of the National Academy of Science, 32 percent of people who try tobacco become dependent, as do 23 percent of those who try heroin, 17 percent who try cocaine, 15 percent who try alcohol and 9 percent who try marijuana.

Dr. Cami and Dr. Farré observed that personality traits like risk-taking and novelty-seeking tendencies, as well as mental disorders, are "major conditioning factors in drug addiction."

An increased risk of drug abuse has been associated with psychiatric disorders like schizophrenia, bipolar disorder, depression and attention deficit hyperactivity disorder, they wrote.

Changing the Brain

In a "perspectives" article in The Journal of the American Medical Association this month, Brian Vastag, reporting on the June conference, wrote, "The brain changes during addiction."

Mr. Vastag explained that all drugs of abuse activated a pleasure pathway in the brain, the "dopamine reward circuit," which is connected to areas that control memory, emotion and motivation. Any activity that activates those pathways reinforces the pleasurable behavior.

"Eventually," he wrote, "the dopamine circuit becomes blunted; with tolerance, a drug simply pushes the circuit back to normal, boosting the user out of depression but no longer propelling him or her toward euphoria."

By repeatedly supplying the body with the substance, a new state of "normal" is created, causing the person to continue using the substance to feel normal.

The changes in the brain, though not permanent, can be long lasting. Dr. Volkow found that the dopamine system of cocaine users remained impaired for up to three months after their last snort.

And despite years of abstinence, former addicts may experience intense cravings when they are exposed to certain cues like watching drug use by a movie character.

The Barcelona experts, in discussing the addiction mechanisms, noted, "Long-term administration of addictive drugs produces alterations in the brain that increase vulnerability to relapse and facilitate craving even months or years after successful detoxification."

Those changes involve cognitive areas and drug-rewarding circuits.

For someone who used drugs to relieve an emotional problem or psychiatric disorder that was not otherwise treated, the temptation to revert to the assuaging drug can be irresistible. Without follow-up treatment for both the addictive disorder and the underlying mental illness, the chances of a lasting recovery from addiction may be slim.

Further, there is clearly not one route to recovery. Some addicts manage to kick their habits without any outside help; others require month long inpatient programs and continued reinforcement, either professional or lay. Still others may need a year of outpatient treatment plus aftercare. Many former addicts find that support groups of fellow former addicts like Alcoholics Anonymous and Narcotics Anonymous help them maintain their drug-free status.

Because prolonged exposure to abused drugs results in long-lasting changes in the brain, "addiction should be considered a chronic medical illness," the Barcelona scientists said. As with other chronic illnesses, including hypertension and diabetes, addiction and its treatment require "long-term strategies based on medication, psychological support and continued monitoring," they concluded. In addition, other experts have suggested, treatment of addiction should be fully insured with no limit on the number of visits covered.