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Dopamine Response to Psychosocial Stress in Chronic Cannabis Users: A PET Study With [11C]-(+)-PHNO.
- Source :
- Neuropsychopharmacology; Mar2013, Vol. 38 Issue 4, p673-682, 10p, 1 Color Photograph, 3 Charts, 2 Graphs
- Publication Year :
- 2013
-
Abstract
- A number of addictions have been linked with decreased striatal dopamine (DA) receptor availability and DA release. Stress has a key role in cannabis craving, as well as in modulation of dopaminergic signaling. The present study aimed to assess DA release in response to a laboratory stress task with [<superscript>11</superscript>C]-(+)-PHNO positron emission tomography in cannabis users (CU). Thirteen healthy CU and 12 healthy volunteers (HV) were scanned during a sensorimotor control task (SMCT) and under a stress condition using the validated Montreal imaging stress task (MIST). The simplified reference tissue model (SRTM) was used to obtain binding potential (BP<subscript>ND</subscript>) in striatal subdivisions: limbic striatum (LST), associative striatum (AST), and sensorimotor striatum (SMST). Stress-induced DA release (indexed as a percentage of reduction in [<superscript>11</superscript>C]-(+)-PHNO BP <subscript>ND</subscript>) between CU and HV was tested with analysis of variance. SMCT BP<subscript>ND</subscript> was significantly higher in CU compared with HV in the AST (F=10.38, p=0.003), LST (F=4.95, p=0.036), SMST (F=4.33, p=0.048), and whole striatum (F=9.02, p=0.006). Percentage of displacement (change in BP<subscript>ND</subscript> between SMCT and MIST PET scans) was not significantly different across groups in any brain region, except in the GP (−5.03±14.6 in CU, compared with 6.15±12.1 in HV; F=4.39, p=0.049). Duration of cannabis use was significantly associated with stress-induced [<superscript>11</superscript>C]-(+)-PHNO displacement by endogenous DA in the LST (r=0.566, p=0.044), with no effect in any other brain region. In conclusion, despite an increase in striatal BP<subscript>ND</subscript> observed during the control task, chronic cannabis use is not associated with alterations in stress-induced DA release. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0893133X
- Volume :
- 38
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Neuropsychopharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 85435002
- Full Text :
- https://doi.org/10.1038/npp.2012.232