Paroxetine treatment also led to increased social preference in both sexes under normal conditions (without stress in this case), while it reduced social novelty, leading to a discrimination index below 50%, in males only, probably by specifically blocking neuronal serotonin transporter (SERT), which affects males more and increases their chances of ADHD [52,53]. This evidence concerns the gene SLC6A4 and attention deficit-hyperactivity disorder.