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...
Journal of Consulting and Clinical Psychology
July 18, 2011
Nicole Geschwind, Frenk Peeters, Marjan Drukker et al.
440 citations
OBJECTIVE: To examine whether mindfulness-based cognitive therapy (MBCT) increases momentary positive emotions and the ability to make use of natural rewards in daily life. METHOD: Adults with a life-time history of depression and current residual depressive symptoms (mean age = 43.9 years, SD = 9.6; 75% female; all Caucasian) were randomized to MBCT (n = 64) or waitlist control (CONTROL; n =...
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
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...
The British Journal of Psychiatry
December 31, 2009
Agna A. Bartels‐Velthuis, Jack A. Jenner, G. van de Willige et al.
105 citations
BACKGROUND: Hearing voices occurs in middle childhood, but little is known about prevalence, aetiology and immediate consequences. AIMS: To investigate prevalence, developmental risk factors and behavioural correlates of auditory vocal hallucinations in 7- and 8-year-olds. METHOD: Auditory vocal hallucinations were assessed with the Auditory Vocal Hallucination Rating Scale in 3870 children....
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...
Acta Psychiatrica Scandinavica
September 19, 2008
Cécile Henquet, Araceli Rosa, Philippe Delespaul et al.
117 citations
OBJECTIVE: A functional polymorphism in the catechol-o-methyltransferase gene (COMT Val(158)Met) may moderate the psychosis-inducing effects of cannabis. In order to extend this finding to dynamic effects in the flow of daily life, a momentary assessment study of psychotic symptoms in response to cannabis use was conducted. METHOD: The experience sampling technique was used to collect data on...
Psychological Medicine
February 26, 2008
Cécile Henquet, Jim van Os
9 citations
symptom experience amongst people with a mental illness : a commentary
Psychological Medicine
April 1, 2007
Audrey Cougnard, Machteld Marcelis, Inez Myin-Germeys et al.
Background. Research suggests that low-grade psychotic experiences in the general population are a common but transitory developmental phenomenon. Using two independent general population samples, the hypothesis was examined that common, non-clinical developmental expression of psychosis may become abnormally persistent when synergistically combined with developmental exposures that may impact...
European Psychiatry
June 1, 2005
Anton Grech, Jim van Os, Peter B. Jones et al.
AbstractPurposeTo test the hypothesis that recent onset psychotic patients who use cannabis will have psychotic symptoms that are more severe and more persistent than those who do not use cannabis.Subjects and methodsWe carried out a 4-year follow-up study of a cohort of 119 patients with recent onset of psychosis. The patients were divided into four groups according to duration of cannabis...
Addiction
October 1, 2004
N. C. Stefanis, Philippe Delespaul, Cécile Henquet et al.
ABSTRACTAims To investigate the effect of exposure to cannabis early in adolescence on subclinical positive and negative symptoms of psychosis.Design Cross‐sectional survey in the context of an ongoing cohort study.Setting Government‐supported general population cohort study.Participants A total of 3500 representative 19‐year olds in Greece.Measurements Subjects filled in the 40‐item Community...