Coulmier was born at Dijon. His semi-enlightened administration of Charenton was of concern to France's medical establishment, which opposed Coulmier because he was not a medical doctor. He retained many of the treatment practices which are nowadays termed brutal, including locking patients in a wicker cage, making use of straitjackets and using terror baths. He also employed treatments that at the time were considered quite advanced, including diets, bleeding, and purges. After Napoleon's fall and the restoration of the Bourbons, Coulmier was relieved of his duties, probably because of his revolutionary past.
Despite his significant work in psychotherapy, today de Coulmier is known primarily for his interactions with the Marquis de Sade, having been the asylum director when Sade was institutionalized. Coulmier provided Sade with writing supplies, permitted Sade's wife to live in the asylum, and allowed Sade to produce a play which featured other asylum residents as actors.
In the film Quills, he was portrayed by Joaquin Phoenix; this drew criticism on the part of historians and disabled activists, as the real Coulmier was extremely short, and has been described as a hunchback. Coulmier is also represented in Peter Weiss's famous play The Persecution and Assassination of Jean-Paul Marat as Performed by the Inmates of the Asylum of Charenton Under the Direction of the Marquis de Sade.