Neuroscience 2003 Abstract
| Presentation Number: | 449.11 |
|---|---|
| Abstract Title: | Differences in regional brain function due to marijuana use by methamphetamine abusers. |
| Authors: |
Voytek, B. T.*1
; Berman, S.1
; Simon, S. L.1
; Ling, W.1
; Hayashi, K.2
; London, E. D.1
1Psychiatry, UCLA, Los Angeles, CA 2Neurol., UCLA, Los Angeles, CA |
| Primary Theme and Topics |
Neurological and Psychiatric Conditions - Addiction and Drugs of Abuse -- Opioids and others |
| Secondary Theme and Topics | Neurological and Psychiatric Conditions<br />- Addiction and Drugs of Abuse<br />-- Amphetamines |
| Session: |
449. Addiction and Drugs of Abuse: Opioids & Others III Slide |
| Presentation Time: | Monday, November 10, 2003 3:30 PM-3:30 PM |
| Location: | Morial Convention Center - Room 393 |
| Keywords: | DRUG ABUSE, BRAIN IMAGING, PET, GLUCOSE |
Most studies of human drug abuse highlight dependence on one primary agent without explicitly considering use of other psychoactive agents such as marijuana (MJ). We previously showed regional cerebral dysfunction in methamphetamine (MA) abusers, particularly in limbic/paralimbic areas, and now assess the combined effects of MJ and MA on cerebral function.
We studied 14 MA abusers who reported MA as their drug of choice, had on average used MA for >8 years, and used it on most of the 30 days prior to entering the study. We separated this sample into one group of subjects who reported no substantial drug use other than MA abuse (-MJ, n=7), and another group of subjects who either used MJ frequently (>1 joint/wk) or met DSM-IV criteria for THC dependence (+MJ,n=7). Both groups abstained from all illicit drug use for 5–11 days before assay of global and regional cerebral glucose metabolism (CMRglc, rCMRglc) with PET during performance of an attentional task. The +MJ group had 6% lower CMRglc than the -MJ group, with lower rCMRglc in lateral orbitofrontal cortex, insula, caudate nucleus, thalamus, amygdala, and cerebellar vermis (6-9%), and a slightly greater effect (10-14%) in dorsolateral prefrontal, midcingulate, and striate cortices.
When scaled to CMRglc, rCMRglc in medial orbitofrontal cortex and medial temporal lobe was 3-8% higher in +MJ subjects. SPM99 (small volume correction) confirmed this finding in medial temporal lobe in the +MJ group and also showed clusters of higher relative activity (corrected p's<0.04) in dorsal and ventral striatum, thalamus, and lateral temporal lobe. Whole brain SPM analysis shows a cluster of higher relative activity (6008 voxels, p<0.0005) around the right hippocampus.
It is apparent, therefore, that MJ use (even without dependence) can affect brain function in MA abusers. The use of MJ is an important factor to consider in studies of drug dependence.
We studied 14 MA abusers who reported MA as their drug of choice, had on average used MA for >8 years, and used it on most of the 30 days prior to entering the study. We separated this sample into one group of subjects who reported no substantial drug use other than MA abuse (-MJ, n=7), and another group of subjects who either used MJ frequently (>1 joint/wk) or met DSM-IV criteria for THC dependence (+MJ,n=7). Both groups abstained from all illicit drug use for 5–11 days before assay of global and regional cerebral glucose metabolism (CMRglc, rCMRglc) with PET during performance of an attentional task. The +MJ group had 6% lower CMRglc than the -MJ group, with lower rCMRglc in lateral orbitofrontal cortex, insula, caudate nucleus, thalamus, amygdala, and cerebellar vermis (6-9%), and a slightly greater effect (10-14%) in dorsolateral prefrontal, midcingulate, and striate cortices.
When scaled to CMRglc, rCMRglc in medial orbitofrontal cortex and medial temporal lobe was 3-8% higher in +MJ subjects. SPM99 (small volume correction) confirmed this finding in medial temporal lobe in the +MJ group and also showed clusters of higher relative activity (corrected p's<0.04) in dorsal and ventral striatum, thalamus, and lateral temporal lobe. Whole brain SPM analysis shows a cluster of higher relative activity (6008 voxels, p<0.0005) around the right hippocampus.
It is apparent, therefore, that MJ use (even without dependence) can affect brain function in MA abusers. The use of MJ is an important factor to consider in studies of drug dependence.
Supported by 1 Y01 DA 50038 & MOI RR 00865
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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