SLC6A3 and schizophrenia: Notably, a meta-analysis of PET and SPECT studies investigating DAT density in schizophrenia patients’ striatum found no significant differences with matched controls, indicating that the density of striatal dopamine terminals does not differ between patients and controls [179] and rejecting the hypothesis that presynaptic hyperdopaminergia may be due to the increased number of dopamine terminals rather than dopamine accumulation in presynaptic sites (Table 5).