Psychological Medicine
October 1, 2011
Rebecca Kuepper, Jim van Os, Roselind Lieb et al.
BackgroundCannabis use is considered a component cause of psychotic illness, interacting with genetic and other environmental risk factors. Little is known, however, about these putative interactions. The present study investigated whether an urban environment plays a role in moderating the effects of adolescent cannabis use on psychosis risk.MethodProspective data (n=1923, aged 14–24 years at...
BMJ
March 1, 2011
Rebecca Kuepper, Jim van Os, Roselind Lieb et al.
307 citations
OBJECTIVE: To determine whether use of cannabis in adolescence increases the risk for psychotic outcomes by affecting the incidence and persistence of subclinical expression of psychosis in the general population (that is, expression of psychosis below the level required for a clinical diagnosis). DESIGN: Analysis of data from a prospective population based cohort study in Germany (early...
The British Journal of Psychiatry
September 30, 2010
Cécile Henquet, Rebecca Kuepper
16 citations
A recent study by Morgan and colleagues found that cannabidiol attenuates the acute cognitive effects of delta-9-tetrahydrocannabinol (THC). This is of interest as THC has been associated with the detrimental effects of cannabis on mental health in at-risk users, and the potency of cannabis is increasing across Europe.
The British Journal of Psychiatry
May 31, 2010
Cécile Henquet, Jim van Os, Rebecca Kuepper et al.
124 citations
BACKGROUND: Little is known about the experiential dynamics of the interaction between cannabis and vulnerability to psychosis. AIMS: To examine the effects of cannabis on psychotic symptoms and mood in patients with psychosis and healthy controls. METHOD: Patients with a psychotic disorder (n = 42) and healthy controls (n = 38) were followed in their daily lives using a structured...
European Psychiatry
2009
Rebecca Kuepper, Inez Myin-Germeys, M. Konings et al.
2 citations
Frequent use of cannabis has been associated with poor outcome in patients with psychosis or schizophrenia, and research has become more and more interested in the question whether cannabis may actually cause psychosis or schizophrenia. Since only a minority of cannabis users eventually develops psychosis or schizophrenia, cannabis is suggested to be a component cause, potentially interacting...
Schizophrenia Bulletin
November 1, 2008
Cécile Henquet, Marta Di Forti, Paul D. Morrison et al.
Cannabis use is considered a contributory cause of schizophrenia and psychotic illness. However, only a small proportion of cannabis users develop psychosis. This can partly be explained by the amount and duration of the consumption of cannabis and by its strength but also by the age at which individuals are first exposed to cannabis. Genetic factors, in particular, are likely to play a role in...