BDNF and attention deficit-hyperactivity disorder: The protein activity-based unsupervised clustering was somehow associated to response level, and PCA analysis revealed some relevant proteins that could be exerting this effect, including: dopamine signaling-related AKT proteins (99), neurotrophins related to neural viability and dopamine regulation in ADHD (100–103), circadian rhythm proteins related to ADHD and comorbidities–associated sleep disturbances (104–106), and cytokines related to neuroinflammation and Th2 response and ADHD (107–110).