CAMBRIDGE, Mass.--MIT researchers reported recently in the Psychopharmacology Bulletin that a high-carbohydrate dietary supplement can help patients who experience weight gain while taking antidepressants.

Even though the high-carbohydrate regimen altered serotonin levels, it did not alter the antidepressants' effectiveness.

The regimen, which includes a high-carbohydrate drink developed at MIT based on research conducted here, also helped non-medicated obese individuals, the researchers reported. All participants lost between 12 and 26 pounds during the 12-week study.

Patients taking psychotropic medications such as antidepressants that increase the activity of serotonin in the brain sometimes gain weight by overeating sweet and starchy foods.

The drugs work by blocking a serotonin receptor that also regulates protein and carbohydrate intake and mediates feelings of being sated. Because these same receptors are involved in the drugs' therapeutic effects, the drugs often cause weight gain.

AFFECTING MOOD AND APPETITE

The researchers wanted to see whether increasing brain serotonin production by giving patients a carbohydrate-rich beverage twice a day could reverse the obesity caused by antidepressants without diminishing the drugs' therapeutic effects.

They found that obese individuals who had gained weight while taking psychotropic drugs are able to lose just as much weight as non-medicated obese individuals. The regimen increased serotonin levels in their brains with no loss of drug effectiveness.

Co-author Judith J. Wurtman, visiting scientist at MIT's Clinical Research Center (CRC), explores the role of carbohydrates in the brain and their connection to weight loss. In the 1970s, Richard Wurtman, C. H. Green Distinguished Professor at MIT and director of the CRC, and colleagues first showed that eating carbohydrates raises brain serotonin levels. Serotonin affects mood and appetite.

Judith Wurtman later showed that carbohydrate craving is associated with serotonin-linked changes in mood, and that women with premenstrual syndrome (PMS) sometimes overeat carbohydrates and gain weight. She speculated that this overeating increases brain serotonin, which diminishes feelings of depression and anger.

COUNTERING THE ATKINS DIET

A cover story in a recent New York Times magazine explored a hypothesis that refutes the currently accepted food guide pyramid: it's not fat that makes us fat, but carbohydrates. The most well-known proponent of this hypothesis is Dr. Robert Atkins, author of the Diet Revolution books that advocate eating mostly protein and fat and almost no carbohydrates.

"Our study refutes the weight loss approach featured in the New York Times magazine," Judith Wurtman said. "The paper describes the successful weight loss by people who have gained weight on psychotropic drugs using our carbohydrate-serotonin approach. Clearly, these people would not have benefited from a diet that eliminates carbohydrates.

"The New York Times article treated obesity as a physiological disorder, but it ignored the reasons why people need to eat carbohydrates: the brain's need to synthesize serotonin because of stress or chronic use of anti-depressants," she said.

The study, supported by a grant from the Center for Brain Sciences and Metabolism Charitable Trust, was conducted at the TRIAD Weight Management Center at McLean Hospital in Belmont, Mass. In addition to Judith Wurtman, program director of TRIAD and Janine M. McDermott, research affiliate in the CRC and TRIAD program manager, authors include Karen Duca, assistant professor of biology at Tufts University and Philip Levendusky, associate professor of psychiatry at Harvard Medical School.