The Spring Grove Experiment is a series of lysergic acid diethylamide (LSD) studies performed from 1963 to 1976 on patients with psychotic illnesses at the Spring Grove Clinic in Catonsville, Maryland. These patients were sponsored by a federal agency called the National Institute of Mental Health to be part of the first study conducted on the effects of psychedelic drugs on schizophrenics. Then, the Spring Grove Experiments were adapted to study the effect of LSD and psychotherapy on patients including alcoholics, heroin addicts, neurotics, and terminally-ill cancer patients. The research done was largely conducted by the members of the Research Unit of Spring Grove State Hospital. Significant contributors to the experiments included Walter Pahnke, Albert Kurland, Sanford Unger, Richard Yensen, Stanislav Grof, William Richards, Francesco Di Leo and Oliver Lee McCabe. Later, Spring Grove was rebuilt into the Maryland Psychiatric Research Center, where studies continued to be performed for the advancement of psychiatric research. This study on LSD is the largest study on psychedelic drugs to date.