In this retrospective of electroencephalograms were to identify a surrogate biomarker for the Dopamine D2 receptors in the brain by comparing patients diagnosed with Schizophrenia taking Atypical Antipsychotics to Depressive patients medicated with Selective Serotonin Reuptake Inhibitors. To achieve this, thirty-seconds of resting EEG were spectrally transformed in sLORETA. Three-dimensional statistical non-paramentric maps (SnPM) for the sLORETA Global Field Power within each band were then computed. Our results illustrated that the Right Superior Frontal Gyrus (t=2.049, p=0.007), along the dopamine mesolimbic pathway, had higher neuronal oscillations in the delta frequency band in the 100 Schizophrenia patients as compared to the 32-depressive female patients. The comparisons with both the 48 depressive patient cohort or the sixteen male depressive patient cohort did not yield any statistically significant findings. We conclude that the Superior Frontal Gyrus should be investigated as a possible surrogate biomarker for preclinical and clinical drug discovery in neuropharmacology.