The compulsion for either food or drugs emerges from the same neural
pathways and chemicals in the brain, suggesting that overeating and
substance abuse are "two sides of the same coin," according to a report published today in Psychiatric News.
The report is a summary of evidence presented last month at a
conference sponsored by the National Hispanic Science Network on Drug
Abuse. Several scientific presentations promoted the idea that
addictive drugs hijack the normal food reward system that humans need
to survive. For example, the dopamine signaling system in the brain is
activated by food cues, such as the smell of turkey roasting in the
oven. This system drives us to eat and feel satisfied after eating. But
brain-imaging studies show this same system is at the core of drug
"Drugs activate [dopamine
release] in a much more efficient and potent way than food," said Dr.
Nora Volkow, director of the National Institute on Drug Abuse. "The
motivational drive produced by drugs is much more intense than food."
studies show compulsive overeating shares many "characteristics with
drug addition," Volkow said. The amount of dopamine receptors in the
brain is reduced in obese people, as it is people with long-term
addiction to drugs. Another study presented at the meeting, by Dr.
Roger McIntyre of the University of Toronto, showed an inverse
relationship between obesity and substance abuse among people with
bipolar disorder. People with bipolar disorder have higher-than-average
rates of obesity and substance abuse.