TUESDAY, May 23 (HealthDay News) -- A sweet drink twice a day might help people beat the blues.

A new, small study showed that two special high-carbohydrate drinks a day helped clear symptoms of Seasonal Affective Disorder (SAD), a seasonal depression that appears mostly during the winter, when people receive minimal sunshine.

Sufferers tend to reach for sweets and other carbs, said lead researcher Dr. David Mischoulon, an assistant professor of psychiatry at Harvard Medical School.

"Most people would eat more of the chocolate bars and the other sweets," he said. "But if you take the drink a couple of times a day, it's a couple of hundred calories, whereas one chocolate bar may have more calories than that."

Carbohydrates help to stimulate the brain chemicals tryptophan and serotonin, and therefore reduce mood swings, sleeplessness and other symptoms of depression, he explained.

Yes, tryptophan is the amino acid whose presence in turkey and other foods is said to cause people to become sleepy.

"That's an old wive's tale," said Mischoulon. "It's not the tryptophan. The reason people fall asleep after a turkey dinner is because they've eaten a huge amount of food."

In fact, tryptophan turns into serotonin, which helps sleep and mood, he explained.

In the study, 18 people diagnosed with SAD, half of them women, were enrolled in the study. Those who were given a sweet drink, a concoction of various kinds of carbohydrates, twice a day showed improvement in symptoms of depression.

Mischoulon presented the results Tuesday at the American Psychiatric Association meeting in Toronto. Still, he added, there is much work to be done if the drink is ever to be recommended as a treatment.

A well-known SAD researcher thinks the drink will probably prove to be ineffective in the long run.

"I would be skeptical," said Dr. Norman E. Rosenthal, medical director of Capital Clinical Research Associates in Rockville, Md., and author of Winter Blues.

"In my experience, what happens is that although the carbohydrates seem to activate people with SAD, there is a backlash and they have to keep going back for carbohydrates," he said.

"It doesn't turn out to be a sustainable kind of treatment," he said. "I have shifted in my recommendation away from regular high-carbohydrate meals to actually restricting carbohydrates."

More information

To learn more about SAD, visit the National Mental Health Association.