From the Grand Guignol website:
It was Maurey who, from 1898 to 1914, turned the Theatre du Grand-Guignol into a house of horror. He measured the success of a play by the number of people who fainted during its performance, and, to attract publicity, hired a house doctor to treat the more fainthearted spectators. It was also Maurey who discovered the novelist and playwright Andre de Lorde–“the Prince of Terror.” Under the influence of de Lorde (who collaborated on several plays with his therapist, the experimental psychologist Alfred Binet), insanity became the Grand-Guignolesque theme par excellence. At a time when insanity was just beginning to be scientifically studied and individual cases catalogued, the Grand-Guignol repertoire explored countless manias and ‘special tastes’: Andre de Lorde and Leo Marches’s L’Homme de la Nuit (The Man of the Night), for example, presented a necrophiliac, who strangely resembled Sergeant Bertrand, a man sentenced in 1849 for violating tombs and mutilating corpses. L’Horrible Passion (The Horrible Passion), by Andre de Lorde and Henri Bauche, depicted a young nanny who strangled the children in her care. (Like Metenier, de Lorde was often a target of censorship, particularly in England where scheduled touring productions of two of his plays were canceled by the Lord Chamberlain’s censors. The theater of the time, which delighted in vaudeville and bourgeois settings, could not abide the sight of blood or corpses on stage.)
Andre de Lord(1869-1942), the “Prince of Fear” (Prince de la Terrerur): French playwright, the main author of the Grand Guignol plays from 1901-1926. He wrote 150 plays, all of them devoted mainly to the exploitation of terror and insanity, and a few novels. For plays the subject matter of which concerned mental illness he sometimes collaborated with psychologist Alfred Binet, the developer of IQ testing.