Birth and child/adolescent characteristics presented as means ± SD or n (%).

aassessment of symptoms based on fulfilment of criteria according to the Rutter B2/Strengths and Weaknesses of ADHD symptoms and Normal behavior (SWAN) scale.bassessment based on Rutter item number 16.cassessment based on sum of Rutter items 1 and 3.dSWAN subscale consisting of sum of 9 items.eSWAN subscale consisting of sum of 9 items.