Substance-induced psychotic disorders: 13-year data from a de-addiction centre and their clinical implications.

The relationship between substance use and psychotic disorder has been complex. Alcohol, cannabis, amphetamines, hallucinogens, and phencyclidine have been implicated as a causative factor for psychotic disorders. It is important to differentiate substance induced psychotic disorders (SIPDs) from primary psychotic disorders as management of the two conditions is different. There is paucity of research in the area of SIPD particularly from Asia. The present study was a retrospective study and it determines retrospectively the incidence rate and clinical characteristics of the SIPDs over a period of 13 years. The incidence of SIPDs was found to be 1.4% and all the subjects were males. In the present study, only alcohol and cannabis were implicated as causative agents for SIPDs. The most common type of psychosis was schizophrenia like psychosis, being more common in the cannabis group. The other forms of psychosis included delusional type, hallucinatory type and affective psychosis. 20% of the subjects had a change in diagnosis to either schizophrenia or affective psychosis on follow-up. The present study showed that the presentation of SIPDs is similar to the primary psychotic disorder and this has management implication.