Objective  To explore relationships of serum norepinephrine (NE) and dopamine (DA) levels in children with attention deficit hyperactivity disorder with the severity of the disease.

  Methods  A total of 108 children with attention deficit hyperactivity disorder were selected as study group, and 95 normal children were selected as control group. The serum NE and DA levels of the two groups were compared. The serum NE and DA levels of children with different severity of attention deficit hyperactivity disorder were compared. Logistic multivariate regression analysis was used to explore the factors affecting the severity of children's illness; Pearson correlation analysis was used to explore relationships of NE and DA levels in children with attention deficit hyperactivity disorder with the severity of the disease.

  Results  The serum NE and DA levels of the study group were significantly higher than those of the control group (P < 0.05). The levels of serum NE and DA of attention deficit hyperactivity disorder children in the severe group were higher than those in the mild group and moderate group, and were higher in the moderate group than those in the mild group(P < 0.05). Logistic multiple regression analysis showed that decreased serum magnesium level, elevated serum NE level and elevated serum DA level were independent risk factors for severity of attention deficit hyperactivity disorder in children (OR=2.818, 4.473, 3.438, P < 0.05). Serum NE and DA in children with attention deficit hyperactivity disorder were positively correlated with the severity of the disease (r=0.726, 0.645, P < 0.05).

  Conclusion  The levels of serum NE and DA in children with attention deficit hyperactivity disorder are closely related to the severity of the disease, and can be used as important reference indexes for evaluating the severity of children with attention deficit hyperactivity disorder.