Thursday, May 14, 2009

Pseudoneurobiology of addiction

According to an article in Journal of the American Medical Association (JAMA), "During the past 20 years, fundamental advances in the neurobiology of addiction have been made. Molecular and imaging studies have revealed addiction as a brain disorder with a strong genetic component, and this has galvanized research on new pharmacological treatments." This is said without reference.

In a follow-up letter, the authors clarify that they used the term addiction instead of dependence to avoid confusion with physical dependence. "Physical dependence results in withdrawal symptoms when drugs such as alcohol and heroin are discontinued, but the neuroadaptations responsible for these effects are different from those that underlie addiction (compulsive drug-taking condition with loss of control over the intense urges to take the drug even at the expense of adverse consequences)."

Brain mechanisms associated with reward are presumed to be disrupted. Of course, addiction or dependence, whatever you call it, is something to do with the brain. And it's also a habit that may be difficult to break, not least if it's associated with physical withdrawal symptoms. But it's sheer neurologising tautology (as Adolf Meyer used to call it) to think that anything has been explained by calling psychological dependence a brain disorder/disease. It doesn't make sense to say that psychological addiction is caused by a structural brain abnormality, rather than being a functional problem. If specific brain abnormalites have been found in addiction, we'd know what they are.

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