Women who suffer from anorexia are often thought of as having an extraordinary degree of self-control, even if that discipline is used self-destructively.
But a study in the journal Nature Neuroscience suggests that the extreme dieting characteristic of anorexia may instead be well-entrenched habit — behavior governed by brain processes that, once set in motion, are inflexible and slow to change.
The findings may help explain why the eating disorder, which has the highest mortality rate of any mental illness, is so difficult to treat. But they also add to increasing evidence that the brain circuits involved in habitual behavior play a role in disorders where people persist in making self-destructive choices no matter the consequences, like cocaine addiction or compulsive gambling.
The researchers used a brain scanning technique to look at brain activity in 21 women with anorexia and 21 healthy women while they made decisions about what foods to eat. As expected, both the anorexic and the healthy women showed activation in an area known as the ventral striatum, part of the brain’s reward center. But the anorexic women showed more activity in the dorsal striatum, an area involved with habitual behavior, suggesting that rather than weighing the pros and cons of the foods in question, they were acting automatically based on past learning.
New York Times