<h4>Background</h4>Studies have reported the retinoid X receptor (RXR)-peroxisome proliferator-activated receptor-γ (PPAR-γ) axis, a heterodimeric nuclear receptor complex regulating synaptic plasticity and neuroinflammation, in neurodevelopment, with emerging evidence suggesting its disruption contributes to cognitive impairments akin to those in attention deficit hyperactivity disorder (ADHD).<h4>Methods</h4>This study included 104 adolescents with ADHD and 87 age-matched neurotypical adolescents. The gene discussed is PPARG; the disease is attention deficit-hyperactivity disorder.