Psychedelic medicine is having a moment. Just weeks after the U.S. Food and Drug Administration approved Johnson & Johnson's ketamine-like nasal spray for depression, a group of European technology investors ... got together for the largest-ever private financing round for a psychedelic medicine biotech company, ATAI. Psychedelic medicine involves research and investigations into mind-altering substances to treat mental illnesses including addiction, depression and post-traumatic stress disorder. After recreational use of psychedelics became popular in the 1960s, the U.S. government classified most of them "drugs of abuse" with no real medical value. However, recent clinical studies show mounting evidence that some psychedelics can help patients with certain mental illnesses, either in combination with traditional therapies or in cases where nothing else has worked. Now health and technology investors are paying attention. German company ATAI Life Sciences announced on Tuesday that it has raised more than $40 million in new financing. The round valued the company at $240 million, according to a person familiar, making it both the biggest round and the most valuable company in the young space. ATAI is currently funding clinical trials for what it refers to as "formerly stigmatized compounds," including psilocybin, the active compound in psychedelic mushrooms, and arketamine, a different variant of ketamine from the one Johnson & Johnson researched, as potential treatments for depression.