"Well, there's the study by Sidney Cohen which was cited here recently, Journal of Nervous and Mental Disease, 130, 1960. The following is from Jay Stevens' Storming Heaven: "Cohen surveyed a sample of five thousand individuals who had taken LSD twenty-five thousand times. He found and average of 1.8 psychotic episodes per thousand ingestions, 1.2 attempted suicides, and 0.4 completed suicides. 'Considering the enormous scope of the psychic responses it induces,' he concluded, 'LSD is an astonishingly safe drug.""'