Salivary neurosteroid levels and behavioural profiles of children with attention-deficit/hyperactivity disorder during six months of methylphenidate treatment

Objective: This prospective study aimed to investigate the relationships between salivary levels of neurosteroids, including dehydroepiandrosterone (DHEA), cortisol, and DHEA/cortisol ratios, and behavioral symptoms in patients with attention-deficit/hyperactivity disorder (ADHD) during treatment with methylphenidate (MPH). Methods: Fifty-eight ADHD patients (48 boys and 10 girls) were included in the study initially. Forty patients (mean age: 7.77±1.64 years; 32 boys and 8 girls) who completed the study received treatment with oral MPH with a dose range of 5-15 mg/day (mean dose: 12.47±7.74 mg/day.) for 6 months at the discretion of the psychiatrist. DHEA and cortisol levels were determined from saliva samples collected at 0800 h at baseline and 6 months from baseline. ADHD symptoms were evaluated with the Child Behavior Checklist (CBCL). Results: Salivary DHEA levels (mean difference=9.05 pg/mL, p=0.027) and DHEA/cortisol ratios (mean difference=32.42, p=0.007) in ADHD patients were significantly increased, but the cortisol levels did not change significantly. During a 6 month follow-up, all behavioral problems assessed using the CBCL improved significantly. Changes in salivary DHEA levels were positively correlated with changes in salivary cortisol levels (r=0.44, p=0.004); however, changes in salivary levels of DHEA, cortisol, and the DHEA/cortisol ratio were not significantly correlated with change in any subscales of the CBCL. Mean doses of MPH were not significantly correlated with changes in neurosteroid levels and behavioral symptoms. Conclusions: These findings provide evidence that MPH administration might affect DHEA levels and DHEA/cortisol ratios. Whether levels of neurosteroids are directly associated with brain function or behavioral problems in ADHD patients warrants further investigation.