Blunted endogenous opioid release following an oral amphetamine challenge in pathological gamblers - Lingford-Hughes, AR; Mick, I; Myers, J; Stokes, PRA; Erritzoe, D; Colasanti, A; Gunn, RN; Rabiner, EA; Searle, GE; Waldman, AD; Parkin, MC; Brailsford, AD; et al. (Neuropsychopharmacology, 2015)