(Press-News.org) Philadelphia, PA, November 14, 2012 – The ability of cannabis to produce psychosis has long been an important public health concern. This concern is growing in importance as there is emerging data that cannabis exposure during adolescence may increase the risk of developing schizophrenia, a serious psychotic disorder. Further, with the advent of medical marijuana, a new group of people with uncertain psychosis risk may be exposed to cannabis.
For these reasons, it would be valuable if a biological test could be developed that predicted the risk for developing cannabis psychosis. This test could be used to advise people who abuse cannabis or to inform marijuana-prescribing decisions by physicians.
Recent research has implicated a variation in the gene that codes for a protein called RAC-alpha serine/threonine-protein kinase (Akt1) in the risk for cannabis psychosis. However, independent verification of these findings is critical for genetic associations with complex genetic traits, like cannabis-related psychosis, because these findings are notoriously difficult to replicate.
Led by first author Dr. Marta Di Forti at King's College London's Institute of Psychiatry, genetic researchers carried out a case control study to investigate variation in the AKT1 gene and cannabis use in increasing the risk of psychosis.
Di Forti said, "We studied the AKT1 gene as this is involved in dopamine signaling which is known to be abnormal in psychosis. Our sample comprised 489 patients with their first episode of psychosis and 278 healthy controls."
They performed genotyping on all volunteers, and assessed their use of cannabis. They found that AKT1 genotype influences the risk of psychotic disorders in cannabis users, which confirmed the prior report.
"We found that cannabis users who carry a particular variant in the AKT1 gene had a two-fold increased probability of a psychotic disorder and this increased up to seven-fold if they used cannabis daily," explained the authors. "Our findings help to explain why one cannabis user develops psychosis while his friends continue smoking without problems."
"While the AKT1 genotype does not rise to the level of a clinically useful test of the risk for cannabis psychosis, it does show that this source of psychosis risk has a genetic underpinning," commented Dr. John Krystal, Editor of Biological Psychiatry. "This advance also points to cellular signaling mechanisms mediated by Akt1 as being relevant to the biology of cannabis psychosis. This may suggest research directions for novel therapeutics for cannabis psychosis."
Di Forti agreed, adding that "such findings could also help to design health educational campaigns tailored to reach those young people at particular risk."
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The article is "Confirmation that the AKT1 (rs2494732) Genotype Influences the Risk of Psychosis in Cannabis Users" by Marta Di Forti, Conrad Iyegbe, Hannah Sallis, Anna Kolliakou, M. Aurora Falcone, Alessandra Paparelli, Miriam Sirianni, Caterina La Cascia, Simona A. Stilo, Tiago Reis Marques, Rowena Handley, Valeria Mondelli, Paola Dazzan, Carmine Pariante, Anthony S. David, Craig Morgan, John Powell, and Robin M. Murray (doi: 10.1016/j.biopsych.2012.06.020). The article appears in Biological Psychiatry, Volume 72, Issue 10 (November 15, 2012), published by Elsevier.
Notes for editors
Full text of the article is available to credentialed journalists upon request; contact Rhiannon Bugno at +1 214 648 0880 or Biol.Psych@utsouthwestern.edu. Journalists wishing to interview the authors may contact Seil Collins, Press Officer at King's College London's Institute of Psychiatry, at +44 0207 848 5377 or seil.collins@kcl.ac.uk.
The authors' affiliations, and disclosures of financial and conflicts of interests are available in the article.
John H. Krystal, M.D., is Chairman of the Department of Psychiatry at the Yale University School of Medicine and a research psychiatrist at the VA Connecticut Healthcare System. His disclosures of financial and conflicts of interests are available here.
About Biological Psychiatry
Biological Psychiatry is the official journal of the Society of Biological Psychiatry, whose purpose is to promote excellence in scientific research and education in fields that investigate the nature, causes, mechanisms and treatments of disorders of thought, emotion, or behavior. In accord with this mission, this peer-reviewed, rapid-publication, international journal publishes both basic and clinical contributions from all disciplines and research areas relevant to the pathophysiology and treatment of major psychiatric disorders.
The journal publishes novel results of original research which represent an important new lead or significant impact on the field, particularly those addressing genetic and environmental risk factors, neural circuitry and neurochemistry, and important new therapeutic approaches. Reviews and commentaries that focus on topics of current research and interest are also encouraged.
Biological Psychiatry is one of the most selective and highly cited journals in the field of psychiatric neuroscience. It is ranked 5th out of 129 Psychiatry titles and 16th out of 243 Neurosciences titles in the Journal Citations Reports® published by Thomson Reuters. The 2011 Impact Factor score for Biological Psychiatry is 8.283.
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Jerusalem, Nov. 14, 2012 –Can we actually read words and phrases and solve multi-step mathematical problems without our having consciously been aware of them? A team in the Psychology Department at the Hebrew University has conducted a series of experiments that give a positive answer: people can read and do math non-consciously.
The results constitute a challenge to existing theories of unconscious processes, that maintain that reading and solving math problems -- two prime examples of complex, rule-based operations – require consciousness.
The conclusions of the Hebrew ...
This press release is available in German.
Leipzig. Environmental contaminants, such as smoking, are harmful to the human organism in relation to the occurrence of allergies. This is known. Until now, researchers had never investigated whether and to what extent environmental contaminants also affect allergy-relevant stem cells. For the first time a team at the Helmholtz Centre for Environmental Research (UFZ) has found evidence for this: Smoking affects the development of peripheral allergy-relevant stem cells in the blood. In order to present this result Dr. Irina Lehmann ...
A new University of Cincinnati study examines how anxiety sensitivity can thwart the efforts of smokers with asthma to quit smoking. This new direction of research from Alison McLeish, a UC assistant professor of psychology, will be presented on Nov.17, at the 46th annual convention of the Association of Behavioral and Cognitive Therapies (ABCT) in National Harbor, Md.
Anxiety sensitivity, or AS, refers to a person's chronic fear of anxiety-related symptoms – the belief that experiences such as sweaty palms, shallow breathing, headache or rapid heartbeat could bring on ...
University of Cincinnati research is examining the effectiveness of a relationship education program that was created to specifically address the needs of male same-sex couples.
Details on the program and the study, led by Sarah Whitton, a UC assistant professor of psychology, will be presented Nov. 17, at the 46th annual convention of the Association of Behavioral and Cognitive Therapies (ABCT) in National Harbor, Md.
Whitton explains that same-sex couples and heterosexual couples share similar foundations for building successful relationships: commitment, communication ...
Although many people look forward to getting away on vacation or just putting their feet up at home, there are others who can get as anxious about taking time to relax as they would if they were delivering a national address. Christina Luberto, a doctoral student in the University of Cincinnati's Department of Psychology, has now developed a questionnaire, the Relaxation Sensitivity Index (RSI), to examine the phenomenon.
Preliminary findings on the RSI will be presented on Nov.17, at the 46th annual convention of the Association of Behavioral and Cognitive Therapies ...
CAMBRIDGE, Mass. -- On its surface, operating a military drone looks a lot like playing a video game: Operators sit at workstations, manipulating joysticks to remotely adjust a drone's pitch and elevation, while grainy images from the vehicle's camera project onto a computer screen. An operator can issue a command to fire if an image reveals a hostile target, but such adrenaline-charged moments are few and far between.
Instead, a drone operator — often a seasoned fighter pilot — spends most of his shift watching and waiting, as automated systems keep the vehicle running. ...
New research from Queen's University Belfast has uncovered the cause of infertility for 80 per cent of couples previously diagnosed with 'unexplained infertility'.
At present some 50,000 couples require fertility treatment across the UK each year, with the figure reaching one million worldwide. Up to one third of these couples are diagnosed with unexplained or idiopathic infertility. This means that, using current tests, neither partner has been diagnosed with any detectable problem.
Published in Reproductive Biomedicine Online, and carried out by Professor Sheena Lewis ...
There are plenty of effective anticancer agents around. The problem is that, very often, they cannot gain access to all the cells in solid tumors. A new gene delivery vehicle may provide a way of making tracks to the heart of the target.
Many types of tumor form a compact mass, like the phalanx formation of Greek antiquity. And although many drugs are known to be toxic to cancer cells, they are often unable to percolate into the inner recesses of the tumor. Upon intravenous administration, for instance, cytotoxic drugs may only be able to penetrate the outermost layers ...
The breeding population of chinstrap penguins has declined significantly as temperatures have rapidly warmed on the Antarctic Peninsula, according to researchers funded in part by the National Science Foundation (NSF).
The study indicates that changing climatic conditions, rather than the impact of tourism, have had the greatest effect on the chinstrap population.
Ron Naveen, founder of a nonprofit science and conservation organization, Oceanites, Inc., of Chevy Chase, Md., documented the decline in a paper published in the journal Polar Biology. Naveen and coauthor ...
The chrome yellow pigment that renowned post-Impressionist artist Vincent van Gogh favored in priceless masterpieces like Sunflowers, the Yellow House and Wheatfield with Crows is especially sensitive to certain types of light and should be protected to prevent darkening. That's the conclusion of a series of studies in ACS' journal Analytical Chemistry, which could help preserve masterpieces by van Gogh and contemporaries like Gauguin, Cézanne and others.
Koen Janssens and colleagues explain that the chrome yellow pigment used by van Gogh and others in the 19th and 20th ...
