A follow up study of attention deficit hyperactivity disorder: Variations of clinical features, prognostic factors and genetic correlation

Genetic and environmental factors are thought be played important role in development and progression of ADHD. In this follow-up study it is intended to investigate changes in symptoms in adolescence and young adulthood period of ADHD patients who diagnosed in childhood; to investigate the relationship between DRD4, 5-HT2A genes and prenatal environmental risk factors with clinical variations and disease outcome.Fifty patients who diagnosed and followed up between 1994-2001 years now included in the study 7-14 years later. Fifty healthy same-aged people included as control group of this study.DRD4 and 5HT2A gene analysis of patients were performed after detailed clinical evaluation. Eighty- eight percent of patients who were diagnosed in pre-school and primary school period continued to meet the diagnosis criteria of ADHD in adolescence and young adulthood and functionality degrees of those cases were found lower. The relationshıp between prenatal risk factors and birth season with disease outcome found statistical insignificant. The most determined DRD4 gene alleles among ADHD and control groups were 4, 8 and 2 repeat alleles. Although the frequency of 8 repeat allele were higher than reported estimation rates worldwide neither of alleles were found significant for ADHD. However, in presence of 2 repeat alleles for the combined type ADHD diagnosed in childhood persistance ratio was found statistical significant in adolescence and young adulthood. The relationship between -1438A>G and T102C polymorphisms of 5-HT2A gene with treatment response in childhood and ADHD outcome in adolescence and adulthood were found statistical insignificant.