Cheerfulness in the history of psychiatry.

In 1762, Louis-Antoine Marquis de Caraccioli (1719-1803), a prolific writer of the eighteenth century, dedicated a book to a psychological theme that medicine has forgotten: ' gaité ' in French, which we will translate as 'cheerfulness'. At the beginning of the nineteenth century, this work inspired two doctoral theses in medicine, one defended in Montpellier, the other in Paris. In their texts, Louis Monferran (1785-?) and Vincent Rémi Giganon (1794-1857) explored the therapeutic benefits of the medical prescription of cheerfulness. In addition to lifestyle recommendations, they focused on the psychotropic substances available to them: alcohol, coca, hemp and opiates. In an original and novel way, Giganon introduced and recommended ' le gaz oxydule d'azote inspiré ', or inhaled nitrous oxide gas.