Acute changes in cerebral blood flow associated with marijuana smoking

Abstract

Cerebral blood flow (CBF) was measured in experienced (ES) and inexperienced (IS) marijuana smokers with the 133xenon inhalation technique before and after smoking both a high-potency marijuana cigarette and a placebo marijuana cigarette. CBF was measured twice under resting conditions in a control group. Mood states before and after marijuana smoking were quantified with the Profile of Mood States (POMS). Analyses of POMS factors after smoking marijuana revealed IS had an increase in anxiety while ES had a decrease. IS also had a significant increase in depression and decrease in vigor, but neither variable changed in the ES. After marijuana, CBF decreased in IS, but in ES, it increased in comparison with the 2 control runs. In both IS and ES, CBF changes following placebo administration were similar to those associated with marijuana smoking. However, in IS, the marijuana-induced CBF decrease was significantly higher than that associated with placebo. There were no statistically significant differences between the CBF increase seen after placebo and marijuana in ES. Anxiety, anger, fatigue, confusion and depression had significant negative correlations with CBF while vigor correlated positively, but the anxiety factor was the only one to account for a significant percentage of the change (parital correlation) in hemispheric CBF.

Effects of Smoking Marijuana on Brain Perfusion and Cognition

“…Smoking marijuana increased rCBF in ventral forebrain regions that have extensive interconnections with the limbic system. As discussed below, these rCBF increases in "paralimbic" brain regions (Mesulam and Mufson 1982) had both similarities and differences to those reported in previous studies (Volkow et al 1991a,b, 1996: Mathew et al 1989, 1992, 1997, and may underlie the changes in affect that are frequently caused by smoking marijuana. Large regions of the cerebellum had rCBF increases, which have also been reported in previous studies, and may be associated with the intoxication caused by marijuana (Volkow et al 1996).…”

“…An early single photon emission computerized tomography (SPECT) study by Mathew and colleagues using the 133 Xenon inhalation technique compared experienced (a minimum of 10 marijuana cigarettes a week for 3 years), and inexperienced marijuana users before and after smoking marijuana or placebo (Mathew et al 1989). In both groups the effects of smoking placebo were similar to the effects of smoking marijuana.…”

Neuroimaging in cannabis use: a systematic review of the literature

“…Anxiety and confusion in chronic users following marijuana smoking have been inversely correlated with regional activity in several brain areas after controlling for multiple comparisons (Mathew et al 1989). The heart rate correlated positively with changes in global CBF following the smoking of a marijuana cigarette (Mathew et al 1992a) and inversely with rCBF in the right frontal, bilateral temporal, parietal and occipital cortices (Mathew et al 1989).…”

Selective Effects of the Endogenous Cannabinoid Arachidonylethanolamide (Anandamide) on Regional Cerebral Blood Flow in the Rat

“…Because specific cognitive or drug-induced challenges are known to induce regionally specific changes in neuronal activity regional cerebral blood flow (rCBF), and glucose utilization (Sokoloff, 1981), various functional metabolic imaging procedures have been employed in an attempt to understand better marijuana's neuroanatomical sites of action. Mathew and colleagues (Mathew et al 1989(Mathew et al , 1992) measured changes in rCBF following acute drug administration. An increase in CBF was seen in experienced versus inexperienced subjects with greater frontal and right hemisphere blood flow seen 30 min after marijuana smoking.…”