TNF and attention deficit-hyperactivity disorder: Results from preliminary analyses that used t-tests and chi squared tests to compare the ADHD and control groups on these variables indicated that the ADHD group differed from controls for the following plasma concentrations: the heightened ADHD symptoms group had higher n-6:n-3s (p = 0.04), higher AA:EPAs (p = 0.007), lower EPA concentrations (p = 0.03) and higher TNF-α concentrations (p < 0.001).