Initial studies reported that elevated maternal cytokine levels, including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), during the third trimester were associated with ADHD symptoms in children aged 4-6 years (β = 0.53, p = 0.006), independent of familial ADHD history [78]. Here, TNF is linked to attention deficit-hyperactivity disorder.