ABSTRACT
Objective:To explore the relationship between serum cortisol and attention deficit hyperactivity disorder (ADHD), and to investigate the application of cortisol in the diagnosis of ADHD, so as to provide clues and theoretical basis for the comprehensive prevention and treatment of ADHD in the future.Methods:Serum cortisol levels were detected in 159 ADHD children [ADHD group, 58 cases of predominately inattentive presentation (ADHD-I), 32 cases of predominately hyperactive/impulsive presentation (ADHD-HI), 69 cases of combined presentation (ADHD-C)], and 58 healthy control children (healthy control group) from July 2018 to June 2019, at Fujian Medical University Union Hospital.The receiver operating characteristic (ROC) was used to evaluate the diagnostic value of serum cortisol levels in ADHD groups.Results:(1) The serum cortisol levels of ADHD-I group[(216.58±70.55) nmol/L], ADHD-HI group[(182.26±51.34) nmol/L]and ADHD-C group[(222.81±75.70) nmol/L]were significantly lower than that of the healthy control group[(344.83±98.17) nmol/L](all P<0.001). The level of cortisol in ADHD-HI group was lower than that in ADHD-I group and ADHD-C group ( P<0.05). (2)According to the ROC analysis of serum cortisol, the area under the ROC curve for the diagnosis of ADHD group was 0.866 (95% CI: 0.814-0.917), the maximum Youden index was 0.583, the corresponding sensitivity was 89.3%, the specificity was 69.0%, and the cut-off was 302.88 nmol/L.When the specificity was 85.0%, 246.13 nmol/L was the diagnostic threshold and its corresponding sensitivity was 71.1%.Under the ROC curve for the diagnosis of ADHD-I group, the area was 0.857 (95% CI: 0.792-0.922), the maximum Youden index was 0.552, the corresponding sensitivity was 69.0%, the specificity was 86.2%, and the cut-off was 243.39 nmol/L.Under the ROC curve for the diagnosis of ADHD-HI group, the area was 0.934 (95% CI: 0.887-0.980), the maximum Youden index was 0.745, the corresponding sensitivity was 96.9%, the specificity was 77.6%, and the cut-off was 261.55 nmol/L.Under the ROC curve for the diagnosis of ADHD-C group, the area was 0.841 (95% CI: 0.774-0.908), the maximum Youden index was 0.559, the corresponding sensitivity was 87.0%, the specificity was 69.0%, and the cut-off was 302.82 nmol/L.In view of parents′ lack of understanding of ADHD behavior, it is suggested that the diagnostic threshold of cortisol level of 246.13 nmol/L should be based on 85.0% specificity principle, combined with behavior verification in clinical practice, so as to improve the diagnostic accuracy. Conclusions:Cortisol levels in ADHD-I, ADHD-HI and ADHD-C groups are lower than that in control group.There is functional impairment of hypothalamic-pituitary-adrenal axis in ADHD children.The level of cortisol has certain accuracy in the diagnosis of simple ADHD and can be used in clinical diagnosis.