Although they look normal, people suffering from body dysmorphic disorder (BDD) perceive themselves as ugly and disfigured.
New imaging research reveals that the brains of people with BDD look normal, but function abnormally when processing visual details. Reported in the December edition of the Archives of General Psychiatry, the UCLA findings are the first to demonstrate a biological reason for patients' distorted body image.
“Our discovery suggests that the BDD brain's hardware is fine, but there's a glitch in the operating software that prevents patients from seeing themselves as others do,” explained Dr. Jamie Feusner, principal investigator and assistant professor of psychiatry at UCLA's Semel Institute. “Now that we've identified a possible physical cause, down the road we may be able to pinpoint ways that patients' brains can be retrained to perceive faces more accurately.”
Individuals with BDD fixate on an imagined flaw in appearance or a slight physical abnormality. To fix their “problem,” they tend to pursue plastic surgery -- sometimes repeatedly. They often feel ashamed, depressed and anxious, increasing their risk of suicide.
Affecting an estimated two percent of the population, BDD tends to run in families and is especially common in persons with obsessive-compulsive disorder (OCD). Thirty percent of people with BDD suffer from eating disorders, which are also linked to a distorted self-image.
Feusner was curious whether BDD patients' brains interfered with the interpretation of visual input, and if so, whether this glitch occurred when looking at faces other than their own.
“We hoped that asking patients to focus on others' faces would allow them to be less emotionally engaged during the experiment,” he said.
For the first time, functional magnetic resonance imaging (fMRI) was used to reveal how the patients' brains processed visual input. The UCLA team outfitted 12 BDD patients with special goggles that enabled them to view digital photos of various faces as they underwent a brain scan.
Each volunteer viewed three types of images. The first type was an untouched photo. The second type was a photo altered to eliminate facial details that appear frequently, such as freckles, wrinkles and scars. This “low frequency” technique blurred the final image.
The third type of image essentially subtracted the blurred second image from the untouched photo. This “high frequency” technique resulted in a finely detailed line drawing.
Feusner's team compared the BDD patients' responses to 12 control subjects matched by age, gender, education and handedness. What the scientists observed surprised them.