SLC6A3 and schizophrenia: There was no evidence indicating altered density of striatal DAT in schizophrenia in a meta-analysis that included thirteen single photon emission tomography (SPECT) or positron emission tomography (PET) studies in schizophrenia [34] and a 4-year follow-up study on SPECT of DAT in neuroleptic-naive first episode schizophrenia patients [35].