Aggression in ADHD: relation to salivary cortisol

Background Study of cortisol levels in patients with ADHD in correlation with aggressive behaviors associated with ADHD has received limited research attention. This factor is essential for comprehending the psychopathophysiology of ADHD and its comorbidities. The present study aimed to investigate the cortisol level in ADHD children and its relation to severity of symptoms and associated aggressive behavior in those children. The sample consisted of 129 patients and 80 healthy controls evaluated by administering the Mini International Neuropsychiatric Interview for Children, The Wechsler Intelligence Scale for Children, Conners' parent rating scale, problem scale of C.B.C.L., and Socioeconomic Status Scale. Salivary cortisol was measured using radio-immune assay. Results Salivary cortisol level in our ADHD subjects was significantly lower (11.826 ng/ml) than in the control group (19.619 ng/ml with P-value 0.001). Our results failed to find any correlation between ADHD symptoms severity and salivary cortisol levels. Severity of delinquent, aggressive, and externalizing behaviors of ADHD children positively correlated with cortisol salivary levels. Conclusion Salivary cortisol levels are lower in children with ADHD relative to age- and sex-matched healthy controls. In addition, there is no obvious correlation between severity of ADHD symptoms and basal salivary cortisol levels. We also concluded that there is positive correlation between delinquent, aggressive, and externalizing behaviors in children with ADHD and their basal salivary cortisol levels.