... modest influences of non-shared environment at each age independently (e2= 0.22 and 0.21,respectively), with these influences being largely age-specific. In addition, we find modest association ... ofMental Health. Author details1SGDP Research Centre, Institute of Psychiatry, Kings College, London, UK.2Psychology Department, Boston University, 64 Cummington St., Boston, MA,USA.Authors’ contributionsNI ... characterised bypervasive, age inappropriate behaviours of inattention,hyperactivity and impulsivity. The current definition ofADHD defines the age of onset of impairing symptomsas occurring before...