The Army is studying the potential consequences of giving stimulants like amphetamines to soldiers to help solve the problem of keeping them alert when they go days without sleep, a newspaper reported.

Officials expect to give stimulants to troops in the field "in the near future," according to a report by the Washington-based Walter Reed Army Institute of Research, which conducted the study.The San Jose Mercury News, which obtained the report, said Tuesday that similar studies are being conducted by the Navy and Air Force.

Army spokesman Ben Smith said the objective is to find drugs that can keep soldiers sharp when they are awake for days. Among those under study are amphetamines, and stimulants such as nicotine, the newspaper reported.

Smith said concerns about side effects have placed their possible use in doubt. Past research has concluded that extended use of amphetamines and their derivatives can lead to paranoia, hallucinations and violent behavior.

"You'd love to find the perfect drug that enhances performance without side effects," Smith said.

The non-classified research has been under way for about four years and is the latest in a series of military studies on jet lag and sleep deprivation, Smith said.