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30-05-2011 | Mental health | Article

Cocaine, psychedelics increase risk for psychotic symptoms


Free abstract

MedWire News: The use of cocaine and psychedelic drugs, such as lysergic acid, increases the risk for psychotic symptoms even when users are not intoxicated, research confirms.

"Several clinical and community-based studies have demonstrated an association between cannabis use and psychotic symptoms," observe Jitender Sareen (University of Manitoba, Winnipeg, Canada) and team.

Although intoxication with the non-cannabinoid illegal substances cocaine, amphetamines, and psychedelics, is known to induce psychotic symptoms, such as delusions, paranoia and hallucinations, less is known about the risk for psychosis in users when not intoxicated.

To investigate, the researchers studied data on 2588 German adolescents who participated in the Early Developmental Stages of Psychopathology (EDSP) study.

Substance use was assessed at baseline and 4- and 10-years later, while psychotic symptoms were assessed at the latter two time points using the Munich-Composite International Diagnostic Interview.

The team assessed associations between lifetime use (at least five times) of cocaine, amphetamines, and psychedelics and the occurrence of two or more psychotic symptoms, compared with use on up to four occasions.

Participants were asked whether their psychotic symptoms were the result of taking medication, drugs, or alcohol to ensure that none of the positive responses were caused by direct effects of these substances, thereby excluding substance-induced psychosis.

At the 10-year follow-up, the cumulative incidence of lifetime cocaine, amphetamine, and psychedelic use among the participants was 5.5%, 6.3%, and 3.2%, respectively, and 8.3% had experienced two or more psychotic symptoms.

After accounting for factors such as age, gender, social class, urbanicity, cannabis use, and other potential confounding factors, the researchers found that lifetime cocaine and psychedelic use were significantly associated with experiencing two or more psychotic symptoms, at odds ratios (ORs) of 1.94 and 2.37, compared with compared with use of these drugs on 0-4 occasions.

There was also an increased risk for two or more psychotic symptoms associated with lifetime amphetamine use, but this became non-significant after adjustment for potential confounders.

After further adjustment for mood or anxiety disorders, the association between lifetime substance use and two or more psychotic symptoms remained significant for lifetime psychedelic use only, at an OR of 3.56.

"Findings from this study contribute to a growing body of literature that suggests that use of non-cannabinoid substances such as cocaine, amphetamines, or psychedelics is associated with psychotic symptoms," the researchers conclude in the journal Acta Psychiatrica Scandinavica.

They add, however, that "there remains a further need for longitudinal data to clarify the temporal sequence and whether substance use is, in fact, a causal factor in experiencing psychotic symptoms."

MedWire ( is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011

By Mark Cowen

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