RESUMEN
Objective To explore the relationship between brain-derived neurotrophic factor (BDNF) and 5-hydroxytryptamine (5-HT) in children with attention deficit hyperactivity disorder (ADHD) plus learning disabilities (LD) and their effects. Methods The present study included 40ADHD children with (15 cases) or without LD (25 cases) who had presented to our institute from January 2011 to October 2011,and 25 healthy children as controls as well.The serum levels of BDNF and 5-HT were compared between the 3 groups.Analysis of variance and linear correlation model were used to assess the levels and correlation of BDNF and 5-HT in the ADHD + LD group. Results The BDNF level significantly decreased in turn from the ADHD+LD group to the ADHD group to the control group (P＜0.05). The 5-HT level significantly increased in the ADHD and control groups compared with the ADHD + LD group (P＜0.05).The serum levels of BDNF and 5-HT were negatively correlated in the ADHD + LD group (r=-0.084,P=0.004). Conclusion Since the serum levels of BDNF and 5-HT are abnormal in children with ADHD plus LD,they may interact with one another and get involved in the pathological process of ADHD.