There's an addition to the physical woes athletes can suffer when they take anabolic steroids to try to build muscles.

It is called body builder's psychosis, a set of disturbances and delusions so extreme that one body builder -- when another driver cut in front of him -- pursued and cornered the offender and smashed in his windshield with a crowbar. Another deliberately drove an old car into a tree at 35 miles an hour while a friend videotaped him. Another said he couldn't be injured if he jumped from a third-story window.

Steroids, synthetic derivatives of the male hormone testosterone, were developed in the 1930s and introduced in the United States in the 1960s. They have various medical uses but are widely used by some athletes for gaining weight and muscle mass, although they have been linked to liver, heart and reproductive disorders.

Doctors at Boston's McLean Hospital, a psychiatric institution, first detected the apparent new side effect in two men hospitalized for psychotic episodes. They then interviewed another 31 steroid users, whom they recruited by ads posted in Boston and Los Angeles gyms.

Three of these had experienced acute psychotic symptoms. One had "heard" voices and noises for several weeks. Another said others were "broadcasting" him their thoughts. Four more had had "subthreshold" psychotic symptoms, including grandiose beliefs such as thinking one could safely jump out of a window.

The first two men were successfully treated once they stopped taking steroids and have shown no more symptoms after two years' follow-up, Drs. Harrison Pope Jr. and David Katz reported in the British medical journal Lancet.