We also assessed the effects of THC on: 1) motor hyperactivity induced by d-amphetamine [38], and 2) dopamine neuron population overactivity in the ventral tegmental area (VTA; [39]), two correlates of positive-like symptoms, as well as 3) endocannabinoid levels in the nucleus accumbens [33,35] and 4) Akt/GSK3β signaling (as this pathway has been involved in the pathogenesis of schizophrenia [40]). Here, GSK3B is linked to schizophrenia.