IACM-Bulletin of February 13, 2011

Science — Cannabidiol improves symptoms of generalized social anxiety disorder in a controlled clinical study

Scientists at the University of Sao Paulo, Brazil, investigated the effects of the natural cannabinoid cannabidiol (CBD) on patients with generalized social anxiety disorder in a simulation public speaking test. Three groups were compared, 12 healthy controls without any medication, 12 patients with anxiety disorder, who received a single dose of CBD (600 mg) and a group of 12 patients, who received a placebo in a double-blind design.

Pre-treatment with CBD significantly reduced anxiety, cognitive impairment and discomfort in the speech performance of patients with social anxiety disorder, and significantly decreased alert in their anticipatory speech. The placebo group presented higher anxiety, cognitive impairment, discomfort, and alert levels when compared with the control group. No significant differences were observed between patients, who had received CBD, and healthy controls in anxiety cores or in the cognitive impairment, discomfort, and alert factors.

(Source: Bergamaschi MM, Queiroz RH, Chagas MH, de Oliveira DC, De Martinis BS, Kapczinski F, Quevedo J, Roesler R, Schröder N, Nardi AE, Martín-Santos R, Hallak JE, Zuardi AW, Crippa JA. Cannabidiol Reduces the Anxiety Induced by Simulated Public Speaking in Treatment-Naïve Social Phobia Patients. Neuropsychopharmacology. 2011 Feb 9. [in press])

News in brief

USA — Montana

On 10 February the Montana House of Representatives voted to repeal the state’s six-year-old medical cannabis law. The House of Representatives is controlled by the Republicans. The House speaker, Mike Milburn, a Republican and sponsor of the repeal bill, said he thought that the arguments about medical use had been a pretext for encouraging recreational use and creating a path to full legalization. The State Senate, also controlled by the Republicans, will also consider the measure. In Montana the medical cannabis law was passed by voters in 2004 and there are currently 27,000 registered patients. (Source: New York Times of 11 February 2011)

Science — Cannabinoid composition in cannabis

Researchers of the RAND Corporation in Santa Monica, USA, investigated changes in THC-level and CBD-level in 5000 cannabis samples in California from 1996 to 2008. Authors noted that the median "THC potency has increased from 4.56 percent in 1996 to 11.75 percent in 2008." They observed the opposite trend for CBD: "The median level of CBD dropped from 0.24 percent in 1996 to 0.08 percent in 2008." This means that the CBD content dropped from low to very low. (Source: Burgdorf JR, et al. Drug Alcohol Depend. 2011 Jan 31. [in press])

Science — Cannabis dependence

At the New York State Psychiatric Institute, USA, a randomized controlled 12-week study with 156 cannabis-dependent adults was conducted. They received either 2x 20 mg dronabinol (THC) daily or placebo. There was no significant difference between treatment groups in the proportion of participants who achieved 2 weeks of abstinence at the end of the maintenance phase (dronabinol: 17.7 per cent; placebo: 15.6 per cent). THC was well-tolerated, and improved withdrawal symptoms. (Source: Levin FR, et al. Drug Alcohol Depend. 2011 Feb 8. [in press])

Science — Circulatory dysfunction in the heart

Researchers of the University Hospital of Geneva, Switzerland, found out that increased plasma levels of anandamide and 2-AG are associated with coronary circulatory dysfunction in obese individuals. The plasma levels of anandamide in obese patients were significantly increased compared to people with normal body weight. (Source: Quercioli A, et al. Eur Heart J. 2011 Feb 8. [in press])

Science — Sativex

Researchers at the National Institute on Drug Abuse in Baltimore, USA, compared effects of THC with Sativex, which contains about equal amounts of THC and CBD. Nine cannabis smokers received either placebo, and about 5 or 15 mg THC (as dronabinol or Sativex). They concluded: "Oral THC and Sativex produced similar, clinically insignificant increases in heart rate, anxiety, and 'good drug effects' with no serious adverse events. Oral and oromucosal THC have slower absorption, lower rate of THC delivery to the brain, and fewer associated adverse events as compared with smoked cannabis." (Source: Karschner EL, et al. Clin Pharmacol Ther. 2011 Feb 2. [in press])

Science — Omega-3 fatty acids and endocannabinoids

French researchers investigated the relationship between omega-3 polyunsaturated fatty acids and endocannabinoids in mice. They found that lifelong omega-3 fatty acid insufficiency "specifically ablates long-term synaptic depression mediated by endocannabinoids" in certain brain regions. They also found a dysfunction of CB1 receptors in these animals. They concluded that "these findings identify a plausible synaptic substrate for the behavioral alterations caused by the n-3 PUFAs deficiency that is often observed in western diets." (Source: Lafourcade M, et al. Nat Neurosci. 2011 Jan 30. [in press])

Science — Krill oil and endocannabinoids

Overweight subjects received either 2 g per day krill oil, fish oil, or olive oil to investigate their effects on endocannabinoid levels. Overweight subjects had higher levels of the endocannabinoid 2-AG compared to normo-weight subjects. Krill oil, which contains high amounts of long-chain omega-3 fatty acids, but not the other oils decreased 2-AG levels within four weeks. (Source: Banni S, et al. Nutr Metab (Lond). 2011;8(1):7.)