Some individuals experience acute psychotic symptoms that are time-linked to ingesting a recreational drug. These symptoms usually resolve within a few days or a week. However, recent evidence indicates that a significant percentage of these people later develop a chronic psychotic illness.
In a potentially important study published in the American Journal of Psychiatry, Marie Stephanie Kejser Starzer, Merete Nordentoft, and Carsten Hjorthøj report on the long-term outcome of individuals who are diagnosed with substance-induced psychosis. They utilize data from the Psychiatric Central Research Register in Denmark, which has records of all inpatient psychiatric treatment since 1969 and all outpatient treatment since 1995. This database allows for decades of longitudinal data to be examined.
For this study, the investigators reviewed the long-term outcomes of all persons who received a diagnosis of substance-induced psychosis between 1994 and 2014 and had no prior diagnosis of a psychotic illness — a group of over 6,700 people. The diagnosis of drug-induced psychosis required symptoms lasting at least 48 hours — linked to intoxication with or withdrawal from the drug.
When the investigators compared this group with a large group of appropriately matched controls, they found a striking increase in the development of either schizophrenia or bipolar disorder in those who had experienced acute psychotic episodes after taking alcohol, opioids, cannabis, sedatives, cocaine, amphetamines, and/or hallucinogens. The most dramatic increases by far occurred in those who exhibited psychotic symptoms following marijuana use.
Starzer, M.S.K., Nordentoft, M., & Hjorthoj, C. (2017 Nov 28). Rates and predictors of conversion to schizophrenia or bipolar disorder following substance-induced psychosis. Am J Psychiatry, epub ahead of print. doi: 10.1176/appi.ajp.2017.17020223.
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