early French psychiatrist who was the first to combine precise clinical descriptions with the statistical analysis of mental illnesses.

A student of Philippe Pinel (Pinel, Philippe), Esquirol succeeded his distinguished teacher as physician in chief at the Salpêtrière Hospital in Paris in 1811, further developing Pinel's diagnostic techniques and continuing his efforts to achieve more humane treatment of the mentally ill. Esquirol provided the first accurate description of mental retardation as an entity separate from insanity, and he also coined the term hallucination. His Des maladies mentales, considérées sous les rapports médical, hygiénique, et médico-légal (1838) has been called the first modern treatise on clinical psychiatry, and it remained a basic text for 50 years. Esquirol anticipated modern views in his suggestion that some mental illnesses may be caused by emotional disturbances rather than by organic brain damage.