The correlation between striatal dopamine D2/D3 receptor availability and verbal intelligence quotient in healthy volunteers

Background. Although a correlation between the central dopaminergic system and intelligence may exist, the results from imaging studies remain inconclusive. The aim Of this Study was to explore the relationship between striatal dopamine D-2/D-3 receptor availability and verbal intelligence quotient (VIQ) using single photon emission computed tomography (SPECT). Method. Striatal D-2/D-3 receptor availability of 64 healthy subjects was determined with the [I-123]liodoberizamide ([I-123] IBZM) ligand. Intelligence quotients (IQs) of the Subjects were measured by the Wechsler Adult Intelligence Scale - Revised (WAIS-R). Results. In addition to age, left striatal D-2/D-3 receptor availability correlated positively with VIQ. In females, left striatal D2/D3 receptor availability was the only variable that correlated significantly with the similarities subtest of VIQ. Conclusions. There is a relationship between left striatal D-2/D-3 receptor availability and verbal intelligence, which varies, predominantly in males.