Studies investigating the relationship between DAT availability and ADHD using PET/SPECT have been inconsistent, with a meta-analysis showing that ADHD medication history may explain this inconsistency89: drug-naive ADHD patients tend to have lower DAT availability compared to controls while ADHD patients treated with psychostimulants display higher DAT availability compared to controls. The gene discussed is SLC6A3; the disease is attention deficit-hyperactivity disorder.