CHARLESTON, S.C. (AP) - A new $10 million study in Charleston is investigating if omega-3 fatty acids - the substance found in fish oil - can reduce the suicide risk among the nation's veterans.

The study is being announced Monday by the Medical University of South Carolina, the Veterans Administration and the National Institutes of Health.

In the controlled study being conducted for the Army, veterans already receiving mental health services will be given smoothies high in omega-3s for a six-month period. Others will be given a placebo.

Previous research has found that deficiencies in omega-3s can cause mental disorders.

The Veterans Administration estimates that 20 percent of the suicides in the nation are committed by veterans and that the rate among vets is almost twice as high as in the general population.