In one such experiment involving the controversial anti-smoking drug Chantix, the Department of Veterans Affairs (VA) took three months to alert its patients about severe mental side effects. The warning did not arrive until after one of the veterans taking the drug had suffered a psychotic episode that ended in a near lethal confrontation with police.

For photos, video of James Elliott, official FDA documents and more, visit the interactive site for the Disposable Heroes report.

Mr. Elliott, a chain smoker, began taking Chantix last fall as part of a VA experiment that specifically targeted veterans with PTSD, opting to collect $30 a month for enrolling in the clinical trial because he needed cash as he returned to school. He soon began suffering hallucinations and suicidal thoughts, unaware that the new drug he was taking could have caused them.

Just two weeks after Mr. Elliott began taking Chantix in November, the VA learned from the Food and Drug Administration(FDA) that the drug was linked to a large number of hallucinations, suicide attempts and psychotic behavior. But the VA did not alert Mr. Elliott before his own episode in February.

In failing to do so, Mr. Elliott said, the VA treated him like a "disposable hero."