Does elevated peripheral benzodiazepine receptor gene expression relate to cognitive deficits in methamphetamine dependence

Background Methamphetamine (METH) is a neurotoxin and psychostimulant drug with potent effects on the central nervous system. With chronic METH administration, an inflammatory glial response is observed as a result of METH-induced neurotoxicity. One inflammatory marker is the peripheral benzodiazepine receptor (PBR). Objective The purpose of the present study was to determine whether PBR expression is changed in METH dependence and whether the changes relate to cognitive deficits. Methods Reverse transcriptase-polymerase chain reaction was used to investigate PBR gene expression in blood samples taken from 14 male subjects with METH dependence and 14 controls. Results The results showed a significant increase in PBR gene expression in METH dependence, suggestive of a systemic inflammatory response. The increase remained elevated for more than 1 year following abstinence from METH use, but eventually returned to normal. Subjects with elevated PBR also exhibited a deficit in one domain of the Wisconsin Card Sorting Test. Conclusion The results suggest that systemic inflammatory effects can be associated with chronic METH abuse, and this may relate to the cognitive deficits seen in METH dependence. Copyright © 2016 John Wiley & Sons, Ltd.