 Starting in 1888 Kloos sought psychiatric treatment from his Tachtiger friend and fellow editor at The New Guide, and psychiatrist, Frederik van Eeden.However, Kloos's mental condition deteriorated, at least partly due to his persistent effort to conceal his homosexuality, and to his increasing alcoholism.He reached his nadir in 1895 when he was picked up in a delirious state and placed temporarily in a sanitarium.