Does using marijuana increase the risk for developing schizophrenia?

Authors: A. Eden Evins, Alan I. Green, John M. Kane, Sir Robin M. Murray
The Journal of Clinical Psychiatry, April 2013

As more US states and other countries consider legalizing marijuana, clinicians need to know the possible effects of this drug. Research has shown a connection between marijuana use and an increased risk for schizophrenia in young people who are vulnerable to developing psycho…

Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia.

Authors: F. M. Leweke, D. Piomelli, F. Pahlisch, D. Muhl, C. W. Gerth, C. Hoyer, J. Klosterkötter, et al
Translational Psychiatry, 20 March 2012

Cannabidiol is a component of marijuana that does not activate cannabinoid receptors, but moderately inhibits the degradation of the endocannabinoid anandamide. We previously reported that an elevation of anandamide levels in cerebrospinal fluid inversely correlated to psychot…

Potential protective effects of cannabidiol on neuroanatomical alterations in cannabis users and psychosis: a critical review.

Authors: Derik Hermann , Miriam Schneider
Current Pharmaceutical Design, 2012

Cannabis use and the development of schizophrenic psychoses share a variety of similarities. Both start during late adolescence; go along with neuropsychological deficits, reduced activity, motivation deficits, and hallucinations suggesting impairment of similar brain structur…

If cannabis caused schizophrenia–how many cannabis users may need to be prevented in order to prevent one case of schizophrenia? England and Wales calculations.

Authors: Matt Hickman, Peter Vickerman, John Macleod, Glyn Lewis, Stan Zammit, et al
Addiction, November 2009

BACKGROUND: We consider how many cannabis users may need to be prevented in order to prevent one case of schizophrenia or psychosis [defined as number needed to prevent (NNP)]. METHOD: Calculation for England and Wales using best available estimates of: incidence of schizophre…

Assessing the impact of cannabis use on trends in diagnosed schizophrenia in the United Kingdom from 1996 to 2005.

Authors: Martin Frisher, Ilana Crome, Orsolina Martino, Peter Croft
Schizophrenia Research, September 2009

A recent systematic review concluded that cannabis use increases risk of psychotic outcomes independently of confounding and transient intoxication effects. Furthermore, a model of the association between cannabis use and schizophrenia indicated that the incidence and prevalen…

Synthetic delta-9-tetrahydrocannabinol (dronabinol) can improve the symptoms of schizophrenia.

Authors: Glenn Schwarcz, Basawaraj Karajgi, Richard McCarthy
Journal of Clinical Psychopharmacology, June 2009

We are reporting improvement of symptoms of schizophrenia in a small group of patients who received the cannabinoid agonist dronabinol (synthetic Delta-9-tetrahydrocannabinol). Before this report, cannabinoids had usually been associated with worsening of psychotic symptoms. I…

Cannabidiol: from an inactive cannabinoid to a drug with wide spectrum of action.

Authors: Antonio Waldo Zuardi
Brazilian Journal of Psychiatry, September 2008

OBJECTIVE: The aim of this review is to describe the historical development of research on cannabidiol. METHOD: This review was carried out on reports drawn from Medline, Web of Science and SciELO. DISCUSSION: After the elucidation of the chemical structure of cannabidiol in 1…

Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug.

Authors: A.W. Zuardi, J.A.S. Crippa, J.E.C. Hallak, F.A. Moreira, F.S. Guimarães
Brazilian journal of medical and biological research, April 2006

A high dose of delta9-tetrahydrocannabinol, the main Cannabis sativa (cannabis) component, induces anxiety and psychotic-like symptoms in healthy volunteers. These effects of delta9-tetrahydrocannabinol are significantly reduced by cannabidiol (CBD), a cannabis constituent whi…

Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study.

Authors: Louise Arseneault, Mary Cannon, Richie Poulton, Robin Murray, Avshalom Caspi, Terrie E Moffitt
BMJ, 23 November 2002

The strongest evidence that cannabis use may be a risk factor for later psychosis comes from a Swedish cohort study which found that heavy cannabis use at age 18 increased the risk of later schizophrenia sixfold. This study could not establish whether adolescent cannabis use w…