Psikiyatride Güncel Yaklaşımlar (Jan 2011)
Genetic Basis of Attention Deficit Hyperactivity Disorder
Abstract
Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neuropsychiatric disorders of childhood. Due to studies reporting that the effects of ADHD diagnosis on functioning may last throughout life, this disorder, which has great importance for child and adolescent psychiatry, started to attract greater attention recently in terms of adult psychiatry. A review, evaluating the results of studies conducted on the genetic basis of ADHD, which started to attract increasing attention both in our country and the world, was thought to help clinicians working in this field. PubMed and Turkish Psychiatry Index online search engines were screened using “attention deficit hyperactivity disorder”, “ADHD”, “genetics” as key words. The data obtained were combined with information gleaned from several textbooks. Based on previous studies, it could easily be concluded that ADHD is one of the most common heritable psychiatric disorder with distinguished genetic features. Despite its importance for diagnosis and treatment, the etiology of ADHD is still not clear and the disorder seems to be a complex problem arising from the effects of both genetic and environmental factors. Although previous studies revealed that ADHD displayed familial and hereditary transmission, stable patterns of Mendelian inheritance could not be discriminated by evaluation of pedigrees. Therefore, many studies have been conducted on the molecular genetic basis of ADHD recently. The previous studies did not report consistent results in identification of the genes responsible for ADHD which has been partially linked to heterogeneity of the disorder. Grouping relevant patients according to comorbidities and persistence in adolescence rather than DSM-IV subtypes could be an important alternative method for overcoming this limitation in the research studies.
