After graduating from Columbia, Adi Da began using a variety of hallucinogenic and other drugs, sometimes heavily. In 1963, after finishing at Stanford, for 6 weeks he was a paid test subject in drug trials of mescaline, LSD, and psilocybin that were conducted at a Veterans Administration hospital in California. He wrote later that he found these experiences "self-validating" in that they mimicked ecstatic states of consciousness from his childhood, but problematic as they often resulted in paranoia, anxiety, or disassociation. For over a year, Adi Da lived with his girlfriend Nina Davis in the hills of Palo Alto. While she worked to support them, he wrote, took drugs, meditated informally, and studied books on hermeticism in order to make sense of his experiences.