PD Dr. Leo Hermle was Chief Physician in the Christophsbad Hospital, Göppingen for 25 years. Beyond psychiatric basic work he has a history in entactogen and psychedelic research. For the „Handbook Psychoactive Substances“ (von Heyden, Jungaberle & Majic, 2018) he contributed two papers. In this video in German language Leo Hermle talks about:
The paper Flashbacks und anhaltende Wahrnehmungsstörungen nach Einnahme von serotonergen Halluzinogenen (authored by Tomislav Majic, Timo T. Schmidt, Leo Hermle) is about a rather rare, but serious pathology when it comes to recreational uses of psychedelics. In his short video, he explains HPPD and what the paper is about.