When most people think of LSD (lysergic acid diethylamide) the image that comes to mind is hallucinating hippies at Woodstock, but the drug’s original use was psychotherapeutic. As early as the 1960s, researchers showed that LSD reduces depression, anxiety and pain in patients with advanced cancer, and recent years have seen a resurgence of interest in the drug’s beneficial effects. In 2014, Swiss psychiatrist Peter Gasser published the results of a study showing that LSD…