Linking substance use with symptoms of subclinical psychosis in a community cohort over 30 years

Abstract

Linking substance use with symptoms of sub-clinical psychosis in a community cohort over 30 yearsRössler, W; Hengartner, M P; Angst, J; Ajdacic-Gross, V Abstract: Aims The aim of the study was to examine the temporal associations between substance use and subclinical psychosis symptoms. Design Data from a prospective community study sampled within a single cohort over 30 years were analysed with discrete-time hazard models. Setting General population-based sample. Participants At initial sampling in 1978 males (n = 292) were 19 and females (n = 299) were 20 years old. Measurements Two psychosis syndromes representing 'schizotypal signs' and 'schizophrenia nuclear symptoms' and various substance use variables including cannabis, alcohol, tobacco and multiple-drug use (i.e. cannabis combined with other drugs). Findings In bivariate analyses, schizotypal signs were predominantly associated with regular cannabis use in adolescence (OR = 2.29, 95% CI 1.32-3.97). Schizophrenia nuclear symptoms were mainly related to alcohol (OR = 1.84, 95% CI 1.00-3.38) and multiple-drug use (OR = 2.35, 95% CI 1.38-4.02) during adolescence. Multivariate analyses showed that, in particular, regular cannabis use during adolescence was associated with the occurrence of subsequent schizotypal symptoms over a 30-year period (OR = 2.60, 95% CI; 1.59-4.23), whereas multiple-drug use in adolescence was associated predominantly with schizophrenia nuclear symptoms (OR = 1.75, 95% CI 1.01-3.03). Alcohol misuse was only slightly associated with the onset of such symptoms. Conclusions A significant portion of the occurrence of subclinical psychosis symptoms in adulthood can be attributed to excessive cannabis and multiple-drug use during adolescence. This is in line with the hypothesis that long-term sensitization of dopaminergic brain receptors plays a role in developing psychotic symptoms. Multivariate analyses showed that in particular regular cannabis use during adolescence was associated with the occurrence of subsequent schizotypal symptoms over a 30-year period (OR=2.60, 95%-CI=1.59-4.23), whereas multiple-drug use in adolescence was predominantly associated with schizophrenia nuclear symptoms (OR=1.75, 95%-CI=1.01-3.03). Alcohol misuse was only slightly associated with the onset of such symptoms.Conclusions: A significant portion of the occurrence of subclinical psychosis symptoms in adulthood can be attributed to excessive cannabis and multiple-drug use during adolescence. This is in line with the hypothesis that long-term sensitization of dopaminergic brain receptors plays a role in developing psychotic symptoms.

Cigarette smoking and cannabis use are equally strongly associated with psychotic-like experiences: a cross-sectional study in 1929 young adults

“…Nonetheless, the results are in line with longitudinal studies linking both cannabis use (Arseneault et al 2002;van Os et al 2002;Henquet et al 2005;Rossler et al 2012) and cigarette smoking to (subclinical) psychotic symptoms (Degenhardt & Hall, 2001;Weiser et al 2004;Wiles et al 2006;Sorensen et al 2011). Furthermore, our data were gathered by self-report on the internet, possibly leading to either over-or under-reporting of undesirable behaviour such as cannabis use.…”

Schizophrenia risk polymorphisms in the TCF4 gene interact with smoking in the modulation of auditory sensory gating

“…In case-control association studies, stratification for smoking behavior may add power to yield stronger gene effects. Moreover, it should be further explored whether nicotine use itself might enhance the risk for schizophrenia as indicated by longitudinal studies showing that beyond cannabis and alcohol use, early consumption of tobacco increases the risk for psychosis (77,78). Finally, an extended endophenotype including electrophysiological gating measures such as PPI or P50 suppression, smoking behavior, and risk genes such as TCF4 may be suitable as an early indicator for a developing psychosis.…”

Association Between Cannabis and Psychosis: Epidemiologic Evidence

“…The Zurich study followed a sample of participants for 30 years (22), finding weak evidence that cannabis use was associated with schizophrenia nuclear symptoms prior to, but not after, adjustment. In the ALSPAC birth cohort, cumulative cannabis use at age 16 was associated with psychotic experiences at age 18 after adjustment for pre-birth and childhood confounders (23).…”