Severe Infection Associated With Increased Risk of Substance-Induced Psychosis

People with a history of severe infection such as hepatitis or sepsis may be more likely to develop substance-induced psychosis than people without such history, suggests a report in AJP in Advance.

Previous research by Carsten Hjorthøj, Ph.D., M.Sc., of Copenhagen University Hospital and colleagues revealed that people with substance-induced psychosis—psychosis that occurs during intoxication and resolves after use of the substance is terminated—are more likely to develop schizophrenia compared with the general population. “However, relatively little is known about the etiology and exact pathophysiological mechanisms of substance-induced psychoses, apart from the obviously necessary component cause of having used the substance in question,” they wrote.

For the current study, Hjorthøj and colleagues analyzed data from nationwide Danish registers that included all people born in Denmark since 1981. The authors were able to obtain information about individuals who experienced substance-induced psychosis, infections, and/or schizophrenia, as well as information about parental substance use disorders and psychosis. The final sample included 2,256,779 individuals, for whom 3,618 cases of substance-induced psychosis were recorded.

Any infection increased the risk of substance-induced psychosis (hazard ratio=1.30), the authors reported. “The risk of substance-induced psychosis was doubled the first two years after a severe infection and remained increased for more than 20 years,” they wrote. “Hepatitis in particular appeared to have such an association, with a more than threefold increase in substance-induced psychosis after adjustment for substance use disorder and other potential confounders.” Additional analysis revealed that hepatitis following substance-induced psychosis is associated with an increase in the risk of conversion to schizophrenia.

The findings support “the hypothesis of an immune-related component not just for schizophrenia but for psychosis in general,” the authors continued. “If the exact mechanisms underlying the psychotogenic properties of infections or the immune response can be identified, this is likely to lead to improvements in treatment for psychotic disorders. … Our findings may also hold direct relevance in terms of secondary and tertiary prevention of both substance-induced psychosis and later conversion to schizophrenia.”

For related information, see the American Journal of Psychiatry study “Rates and Predictors of Conversion to Schizophrenia or Bipolar Disorder Following Substance-Induced Psychosis.”

(Image: iStock/SDI Productions)

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