Modulation of anxiety by acute blockade and genetic deletion of the CB(1) cannabinoid receptor in mice together with biogenic amine changes in the forebrain.

“The CB(1) cannabinoid receptor has been implicated in the control of fear and anxiety. We investigated the effects of genetic and pharmacological blockade of the CB(1) cannabinoid receptor on the behaviour of CD1 mice using three different ethological models of fear and anxiety…

 …in terms of anxiety our findings suggest that under physiological conditions this receptive site seems to be involved in the control of anxiolysis rather than anxiogenesis as suggested previously.”

http://www.ncbi.nlm.nih.gov/pubmed/19162082