....researchers found in a study published online in The American Journal of Psychiatry.
The conversion risk was highest for patients who experienced cannabis-induced psychosis: 47.4% went on to develop schizophrenia or bipolar disorder.
Researchers arrived at their findings after following 6788 patients with no schizophrenia or bipolar disorder history who were diagnosed with substance-induced psychosis between 1994 and 2014.
Identified through the Danish Civil Registration System and the Psychiatric Central Research Register, patients were followed until a diagnosis of schizophrenia or bipolar disorder or death, emigration, or August 2014.
Psychiatric News Alert coverage of the investigation reported the highest risk was among patients age 16-25 years.
In half the cases, conversion to schizophrenia occurred within 3.1 years of substance-induced psychosis. Half the cases of conversion to bipolar disorder, meanwhile, happened within 4.4 years.
“It is important to diagnose new cases of schizophrenia and bipolar disorder as soon as possible and to initiate treatment without delay,” Psychiatric News Alert quoted from the study, “because prolonged psychosis without treatment is associated with a worse prognosis.”