RT Journal
A1 Bhattacharyya S, Crippa J, Allen P, et al
T1 INduction of psychosis byδ9-tetrahydrocannabinol reflects modulation of prefrontal and striatal function during attentional salience processing
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 2012
FD January 1
VO 69
IS 1
SP 27
OP 36
DO 10.1001/archgenpsychiatry.2011.161
UL http://dx.doi.org/10.1001/archgenpsychiatry.2011.161
AB Context 
                  The aberrant processing of salience is thought to be a fundamental factor underlying psychosis. Cannabis can induce acute psychotic symptoms, and its chronic use may increase the risk of schizophrenia. We investigated whether its psychotic effects are mediated through an influence on attentional salience processing.Objective 
                  To examine the effects ofΔ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) on regional brain function during salience processing.Design 
                  Volunteers were studied using event-related functional magnetic resonance imaging on 3 occasions after administration ofΔ9-THC, CBD, or placebo while performing a visual oddball detection paradigm that involved allocation of attention to infrequent (oddball) stimuli within a string of frequent (standard) stimuli.Setting 
                  University center.Participants 
                  Fifteen healthy men with minimal previous cannabis use.Main Outcome Measures 
                  Symptom ratings, task performance, and regional brain activation.Results 
                  During the processing of oddball stimuli, relative to placebo,Δ9-THC attenuated activation in the right caudate but augmented it in the right prefrontal cortex.Δ9-Tetrahydrocannabinol also reduced the response latency to standard relative to oddball stimuli. The effect ofΔ9-THC in the right caudate was negatively correlated with the severity of the psychotic symptoms it induced and its effect on response latency. The effects of CBD on task-related activation were in the opposite direction of those ofΔ9-THC; relative to placebo, CBD augmented left caudate and hippocampal activation but attenuated right prefrontal activation.Conclusions 
                  Δ9-Tetrahydrocannabinol and CBD differentially modulate prefrontal, striatal, and hippocampal function during attentional salience processing. These effects may contribute to the effects of cannabis on psychotic symptoms and on the risk of psychotic disorders.