SLC6A3 and attention deficit-hyperactivity disorder: We found a significant decrease in DAT availability in the left nucleus accumbens [F(1, 7.9615) = 1962.2, p = 0.007641] and a declining trend in the right nucleus accumbens [F(1, 3.9536) = 2623.8, p = 0.0542057) in adults with ADHD compared with HCs.