Correlation between errors on the Wisconsin Card Sorting Test and the availability of striatal dopamine transporters in healthy volunteers

Background: Although studies have indicated that the frontal lobe plays an important role in performance on the Wisconsin Card Sorting Test (WCST) and that basal ganglia play a specific role in frontal lobe function, the role of striatal dopamine (DA) activity in performance on the WCST remains unclear. Methods: We assessed the relation between the availability of striatal dopamine transporters (DATs) and performance on the WCST as a measure of executive function in healthy individuals. We approximated the availability of DATs in 53 healthy volunteers aged 19-61 years by use of single photon emission computed tomography with technetium-99m (^99mTc)-TRODAT-1 as the ligand. The WCST was administered to all participants. Results: The availability of DAT was significantly negatively correlated with perseverative errors on the WCST, both before and after adjustment for body mass index ( r_before = -0.39, p = 0.004; r_after = -0.39, p= 0.005). Limitations: This was an association study; thus, a causal relation between DAT availability and performance cannot be confirmed. Conclusion: Our results suggest that striatal DAT availability may play a role in executive function as measured by the WCST.