UNASSIGNED: @entity11532 is a @entity146 and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher @entity6253 ( @entity6253 ) availability reported in @entity285 , @entity2072 and @entity4784 . Impulsivity, a risk factor across the addictions, has also been found to be associated with higher @entity6253 availability. The aim of this study was to characterize baseline @entity6253 availability and endogenous opioid release in pathological gamblers (PG) using @entity6254 PET with an oral @entity4944 challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two @entity6254 PET scans, before and after an oral administration of 0.5   mg/kg of @entity2254 . The change in @entity6254 binding between baseline and post- @entity4944 scans (  BPND) was assessed in 10 regions of interest (ROI). @entity6253 availability did not differ between PG and HV groups. As seen previously, oral @entity4944 challenge led to significant reductions in @entity6254 BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted @entity4944 -induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions.Neuropsychopharmacology advance online publication, 9 December 2015; doi:10.1038/npp.2015.340.

Blunted Endogenous Opioid Release Following an Oral XXXX Challenge in Pathological Gamblers.

@entity2254 :: ('MESH:D003913', 'Chemical') :: ['d-amphetamine'] @entity6253 :: ('4988', 'Gene') :: ['mu-opioid receptor', 'MOR'] @entity146 :: ('MESH:D001523', 'Disease') :: ['psychiatric disorder'] @entity4784 :: ('MESH:D009293', 'Disease') :: ['opiate addiction'] @entity2072 :: ('MESH:D003042', 'Chemical') :: ['cocaine'] @entity11532 :: ('MESH:D005715', 'Disease') :: ['Pathological gambling'] @entity4944 :: ('MESH:D000661', 'Chemical') :: ['amphetamine'] @entity285 :: ('D000431', 'Chemical') :: ['alcohol'] @entity6254 :: ('MESH:C017114', 'Chemical') :: ['[(11)C]carfentanil']
@entity4944 :: (MESH:D000661,Chemical) :: ['Amphetamine']
