 Although postmortem and neuroimaging studies have found abnormalities in numerous regions of the reward system, few findings are consistently replicated.Some studies have reported reduced NAcc, hippocampus, medial prefrontal cortex (mPFC), and orbitofrontal cortex (OFC) activity, as well as elevated basolateral amygdala and subgenual cingulate cortex (sgACC) activity during tasks related to reward or positive stimuli.These neuroimaging abnormalities are complemented by little post mortem research, but what little research has been done suggests reduced excitatory synapses in the mPFC.