Federal advisers are considering whether a proposed weight-loss drug raises the risk of depression, a finding that could lead to stern warnings on the medication if it is approved.

Sanofi-Aventis AS has told the Food and Drug Administration it wants to sell the drug rimonabant under the brand name Zimulti. Concerns about its psychiatric effects have delayed a final FDA decision on the medication. The agency previously told the French company it would not approve the drug to help smokers quit.

An outside advisory committee was to consider the drug Wednesday.

A final ruling by the FDA is expected by July 27. The agency isn't required to follow the advice of its outside advisers but does so most of the time.

Rimonabant blocks the same pleasure centers in the body activated when pot smokers get the munchies. Blocking the receptors leads to patients eating less and losing weight.

The prescription drug, when used in conjunction with a modest calorie diet and physical exercise, significantly decreases body weight and waist circumference in overweight or obese patients, according to Sanofi-Aventis. In yearlong studies, patients on the drug lost roughly 14 pounds. Those given dummy pills lost only about 4 pounds. Patients regained weight when treatment was stopped after a year, the company said.

What worries FDA reviewers is that the drug's effect on the body's cannabinoid receptors could lead to psychiatric symptoms, including anxiety, phobias, depression and post-traumatic stress disorders.

In studies, 26 percent of patients given Zimulti reported such a symptom, compared with 14 percent of those given sham treatment. Specifically, 9 percent of those treated with the drug reported symptoms of depression, compared with 5 percent given dummy pills.

Sanofi-Aventis seeks to sell 20-milligram Zimulti tablets to the obese and to those who are overweight and have type 2 diabetes, high blood pressure or other conditions that put them at risk of cardiovascular disease.

Obesity rates have exploded in the past two decades. Today, nearly one in three American adults age 20 or older is obese, according to government data.

Generally, anyone with a body mass index, a ratio that takes into account height and weight, greater than 30 is considered obese. The overweight BMI range is 25 to 29.9. Normal is 18.5 to 24.9.

Rimonabant is sold under the brand name Acomplia in Europe.