Muhammad ibn Zakariya al-Razi
Muhammad ibn Zakariya al-Razi (865 – 925), known as Rhazes in the western tradition, was an influential Persian physician, philosopher, and scientist during the Golden Age of Islam, and among the first in the world to write on mental illness and psychotherapy. As chief physician of Baghdad hospital, he was also the director of one of the first psychiatric wards in the world. Two of his works in particular, "El-Mansuri" and "Al-Hawi", provide descriptions and treatments for mental illnesses.