Drug abuse vs. drug dependence.

As the neurobiology of addiction has come into clearer focus over time, our ability to separate fact from fiction in the field of drug dependence has grown rapidly. Beliefs that have been common wisdom for years--that anyone who uses cocaine or heroin inevitably becomes addicted to it, for example--can now be confidently replaced with insights gained from a decade or more of intense research on the biological causes and treatment of addiction.

Dr. Carlton Erickson, professor of Pharmacology/Toxicology and director of the Addiction Science Research and Education Center at the University of Texas, has assembled an intriguing list of such changes in thinking, based on his book, "The Science of Addiction: From Neurobiology to Treatment." The complete list can be found on his "Exploding Drug Myths" page at the University of Texas site.

With his kind permission, I offer a few of these emerging insights. Many of them, Dr. Erickson told me, are understandable only in the context of DSM-IV criteria for drug abuse and drug dependence as listed in "The Diagnostic and Statistical Manual of Mental Disorders."

The DSM table for drug abuse defines it as "A maladaptive pattern of drug use leading to impairment or distress" including one or more of the following symptoms: recurrent use leading to failure to fulfill major obligations; recurrent use which is physically dangerous; drug-related legal problems; continued use despite social or interpersonal problems.

In contrast, the DSM manual defines drug dependence as three or more of the following symptoms: drug tolerance; withdrawal; drug used more often than planned; inability to control drug use; effort expended to obtain the drug; drug use replaces other activities; drug use continues despite knowledge of a persistent problem.

With these definitions in mind--which correspond roughly to "problem drinker/user" in the former case, and "addict" in the latter--here are some of the myths:

MYTH: Therapeutic pain-killers (such as morphine) produce a high rate of addiction. "Since "addiction" means "dependence," writes Erickson, "the likelihood of becoming dependent on opioid pain-killers is actually quite low.... Most people given these pain-killers will go through withdrawal but will never want or need the drug again."

MYTH: Crack is more addicting than cocaine powder. "There is no pharmacological reason why the form of a drug or the route of administration should change the 'addiction' liability of a drug. In fact, science is beginning to realize that the drug is not the cause of 'addiction' rather, the susceptibility of the person to the drug determines how much 'addiction' (dependence) develops."

MYTH: "Substance abuse" is a scientifically valid term. "The word is a weak, wimpy, confusing, inaccurate, and misleading term when applied to drug problems."

MYTH: Alcoholics can drink socially. "There are a few scientific studies that suggest this. But most of these studies look at 'problem drinkers'....'Abusers' can drink socially (that is, under control), whereas truly dependent individuals cannot."

MYTH: All drugs damage brain cells. "Actually, relatively few have been shown to damage brain cells through a toxic effect. These include alcohol (high doses over a long time), 'inhalants'... methamphetamine and MDMA (shown in animal studies with high doses, but not yet in humans)."

MYTH: Drugs cause "addiction." "An interesting scientific question is: If drugs cause 'addiction,' then why doesn't everyone who uses drugs too much, too often, become dependent (addicted)? Scientists are looking into genetic and other unknown factors that cause some people to become dependent while sparing others of this brain pathology."

MYTH: It is possible to overdose on LSD. "LSD is a major hallucinogen and can cause people to jump from tall buildings (for example) in their hallucinogenic state. However, there is no known lethal dose in humans."

MYTH: The more a person is educated about drugs, the less likely they are to become "addicted". "This idea that chemical dependence is preventable is an old one. Strong indirect evident concerning the brain mechanisms involved in dependence tells us that 'addiction' cannot be prevented. If the above statement were true, physicians, nurses, and pharmacists would have a low rate of chemical dependence. Sadly, these health professionals have an incidence of dependence that is at least as high as the general population."

MYTH: Anyone who drinks too much, too often, is an alcoholic. "If the 'too much, too often' myth were true, then most college students would be alcoholics. In fact, most college students ABUSE alcohol, while only 10-15% show dependence on alcohol at some point in their drinking careers."

MYTH: Everyone "has what it takes" to become "addicted" to drugs. "If 'addiction' (dependence) is a chronic medical disease, then why should it be different from other medical diseases? Everyone doesn't 'have what it takes' to get sickle cell anemia, insulin-dependent diabetes, or AIDS."

Author's Bio: 

Dirk Hanson is a freelance science reporter and novelist who lives in Minnesota. His two previous books—The New Alchemists: Silicon Valley and the Microlectronics Revolution, and The Incursion: A Novel—were reviewed in the New York Times, The New Yorker, the Los Angeles Times, Fortune, and other publications. He has written for California Magazine, Omni, CoEvolution Quarterly, Willamette Week, the Whole Mind Newsletter, and other magazines. He has also worked as a business and technology reporter for the Des Moines Register and for numerous trade publications.