Our group carried out a number of double-blind, pseudo-randomized studies on healthy volunteers who had previous minimal exposure to cannabis. All participants were administered 10 mg of d-9-THC, 600 mg of CBD and placebo (flour)

in three different functional magnetic resonance imaging sessions while performing a response inhibition task, a verbal memory task, an emotional task (viewing fearful faces) and an auditory and visual sensory processing task. The overall concluding results showed that Inhibitors,research,lifescience,medical d-9-THC and CBD had different behavioural effects and also, at times, opposing brain activation in various regions [Borgwardt et al. 2008; Fusar-Poli et al. 2009; Bhattacharyya et al. 2009b; Winton-Brown et al. 2011]. D-9-THC caused transient psychotic symptoms and increased the DAPT chemical structure levels of anxiety,

intoxication and sedation, whilst CBD had no significant effect on behaviour or these parameters. In relation to the imaging Inhibitors,research,lifescience,medical data, during the response inhibition task, relative to placebo, d-9-THC attenuated the engagement of brain regions that normally mediate response inhibition, whilst CBD modulated activity in regions not implicated with Inhibitors,research,lifescience,medical this task [Borgwardt et al. 2008]. During the verbal learning and retrieval of word pair tasks, d-9-THC modulated activity in mediotemporal and ventrostriatal regions, whilst CBD had no such effect [Bhattacharyya et al. 2009b]. During an emotional processing task d-9-THC and CBD had

clearly distinct effects on the neural, electrodermal and symptomatic response to fearful faces [Fusar-Poli et al. 2009]. Our results suggest that the effects of CBD on activation in limbic and paralimbic regions may contribute Inhibitors,research,lifescience,medical to its ability to reduce autonomic arousal and subjective anxiety, whereas the anxiogenic effects of d-9-THC may be related to effects in other brain Inhibitors,research,lifescience,medical regions. During the auditory task, again these two compounds had opposite effects in the superior temporal cortex when subjects listened to speech and in the occipital cortex during visual processing [Winton-Brown et al. 2011]. Our group also assessed whether pretreatment with CBD could prevent the acute psychotic symptoms induced by d-9-THC when six healthy volunteers were administered d-9-THC intravenously Adenosine on two occasions, after placebo or CBD pretreatment [Bhattacharyya et al. 2010]. We found that pretreatment with CBD prevented the transient psychotic symptoms induced by d-9-THC. Both animal and human studies indicate that CBD has anxiolytic properties. In fact in a recent double-blind study carried out on patients with generalized social anxiety disorder, it was found that relative to placebo, CBD significantly reduced subjective anxiety and its effect was related to its activity on limbic and paralimbic areas as shown by single photon emission computed tomography [Crippa et al. 2011].