Residual Effects of THC via Novel Measures of Brain Perfusion and Metabolism in a Large Group of Chronic Cannabis Users

Neuropsychopharmacology. 2018 Mar;43(4):700-707. doi: 10.1038/npp.2017.44. Epub 2017 Feb 27.

Abstract

Given the known vascular effects of cannabis, this study examined the neurophysiological factors that may affect studies of brain activity in cannabis users. We conducted a systematic evaluation in 72 h abstinent, chronic cannabis users (N=74) and nonusing controls (N=101) to determine the association between prolonged cannabis use and the following neurophysiological indicators: (1) global and regional resting cerebral blood flow (CBF), (2) oxygen extraction fraction (OEF), and (3) cerebral metabolic rate of oxygen (CMRO2). We found that cannabis users had greater global OEF and CMRO2 compared with nonusers. Regionally, we found higher CBF in the right pallidum/putamen of the cannabis users compared with nonusers. Global resting CBF and regional CBF of right superior frontal cortex correlated positively with creatinine-normalized Δ9-tetrahydrocannabinol (THC) levels. These findings demonstrate residual effects of cannabis use whereby global and regional brain metabolism are altered in those with prolonged cannabis exposure. These neurophysiological alterations should be considered in both research and clinical applications.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Brain / blood supply
  • Brain / diagnostic imaging*
  • Brain / drug effects
  • Brain / metabolism*
  • Cannabis / adverse effects
  • Cannabis / metabolism
  • Cerebrovascular Circulation / drug effects
  • Cerebrovascular Circulation / physiology*
  • Dronabinol / metabolism*
  • Dronabinol / pharmacology
  • Female
  • Gas Chromatography-Mass Spectrometry / methods
  • Humans
  • Magnetic Resonance Imaging / methods
  • Male
  • Marijuana Abuse / diagnostic imaging*
  • Marijuana Abuse / metabolism*
  • Young Adult

Substances

  • Dronabinol