Attention-deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders of childhood and adolescence, affecting 3%-6% of school age children. It is characterized by symptoms of inattention, hyperactivity and impulsivity, showing also a high clinical heterogeneity. Although the precise causes of ADHD are unclear, the influence of genetic factors is strongly suggested by epidemiologic studies, that provide evidences for a large number of investigations with candidate genes. Nowadays, despite the great attention driven to this subject, no gene can be considered as necessary or sufficient to the development of ADHD, and the search for genes that affect this process is still the focus of many investigations. Thus, the objective of this paper is to summarize and discuss the main results on the research with possible susceptibility genes for ADHD.
Attention deficit hyperactivity disorder; Genes; Genetic susceptibility; Association
