The aim of this study is to investigate the inflammatory response in children with this disorder.

Attention deficit-hyperactivity disorder (ADHD) is a prevalent childhood neuropsychiatric disorder, characterized by age-inappropriate and impairing levels of inattention, hyperactivity and impulsiveness. Approximately 5-10% of school-age children are affected by ADHD, and in many cases, symptoms persist into adolescence and adulthood.

Cytokines are key mediators of immune function and can be either pro-inflammatory or anti-inflammatory. Recently few studies have suggested involvement of cytokine pathways in subjects with ADHD.

Polymorphism of IL-1 receptors antagonists' alleles have been suggested in families and subjects suffering from ADHD. Moreover, a new variant of inflammatory bowel disease, another immunological based disease, was recently suggested in children with ADHD and other developmental disorders. There are no other published reports on cytokine production in children who suffer from ADHD.

Inclusion Criteria:

1. A defined condition of ADHD according to TOVA test (TOVA score > (-1.8), Connor's questionnaire (Connor's score > 15 points) and Achenbach's questionnaire;
2. A consent form signed by parents or legal guardianships;

Exclusion Criteria:

1. A history of any other neurological or major psychiatric disorder or other significant medical problems;
2. No current medications;