A clinical sign for persistent harmful cannabis abuse : A pilot study

Eight patients made up of four psychotics with known history of harmful cannabis use and four psychotics with no history of cannabis use together with four subjects, who were non-psychotic non-smokers were studied. The aim of the study was to ascertain the reliability of a clinical sign of ulceration of the pulps of the first and second fingers. Photographs of the fingers were taken and were examined by a dermatologist. The finding clearly demonstrated that those patients with a history of harmful cannabis use showed the ulceration whilst the other psychotics with no known history of cannabis use as well as the control subjects showed no such features. It is suggested that a larger sample should be studied and If the findings prove consistent then it could be readily used to differentiate between harmful cannabis use and functional psychosis.