Name Chris Schubart
Department of Psychiatry
Section Genetic basis of developmental disorders
Function MD, PhD-student
E-mail:
C.Schubart@umcutrecht.nl Tel:+31 88-7556370
Pager: 3947
Supervisor Dr. M. Boks, professor R. Ophoff and professor R. Kahn
Title research
The influence of cannabis use on schizophrenia susceptibility, a gene-environment interaction study in adolescents.
Summary research:
Compelling evidence suggests that cannabis use substantially increases the vulnerability to develop schizophrenia and that genetic factors moderate this influence. With an odds ratio estimated at 2.09 and a prevalence of cannabis use in adolescents of around 9 percent it is apparent that cannabis use poses a serious risk for developing schizophrenia. However, the molecular mechanism by which cannabis increases the risk to schizophrenia and the role genetic factors herein is still largely unknown.
We have collected information on drug use and symptoms of psychosis by means of the Community Assessment of Psychic Experiences (CAPE) in a sample of now 17.000 adolescents. Preliminary analyses confirm that cannabis use is associated with higher levels of psychosis. Further study of the interaction between genes and cannabis exposure is essential to identify the genetic factors that underlie the effects of cannabis in the aetiology of schizophrenia.
This study aims to identify genetic variation that underlies the interaction between genes, cannabis use and the risk to develop schizophrenia. We propose a two-stage genome wide association study in highly selected subjects to overcome the methodological difficulties that are associated with studies of gene-environment interaction. Population-based selective sampling of heavy- and non users of cannabis, and those with many symptoms and no symptoms, leads to substantially reduction of required sample size while maintaining statistical power. In the first stage, DNA of a highly selected group (N=520) will be subject to a whole genome screen, in stage two selected SNP’s from stage one will be genotyped in an additional sample (N=880).
Identification of the genetic factors that regulate the influence of cannabis use on the development of schizophrenia will lead to a better understanding of the effects of cannabis on the brain as well as contribute to the understanding of the aetiology of schizophrenia. It will provide the starting point of further molecular studies with the ultimate goal of early detection, prevention and treatment of schizophrenia.
PublicationsSchubart CD, Mturi N, Beld MG, Wertheim PM, Newton CR. Role of viruses in Kenyan children presenting with acute encephalopathy in a malaria-endemic area. Am J Trop Med Hyg. 2006 Dec;75(6):1148-50.
Boks MP, Schipper M, Schubart CD, Sommer IE, Kahn RS, Ophoff RA. Investigating gene environment interaction in complex diseases: increasing power by selective sampling for environmental exposure.Int J Epidemiol. 2007 Dec;36(6):1363-9.
Wijkstra J, Schubart CD, Nolen WA. Treatment of unipolar psychotic depression: The use of evidence in practice guidelines.World J Biol Psychiatry. 2007 Oct 24:1-7
Schubart CD, Boks MPM, EJ Breetvelt, WA van Gastel, Beetz SL, Sommer IEC, Ophofff RA, Kahn RS. Cannabis Use and Sub Clinical Psychotic Symptoms: is Public Mental Health at Risk? European Neuropsychopharmacology, Volume 19 Suppl. 1, March 2009.