Increased Cortisol after Stress is Associated with Variability in Response Time in ADHD Children

PURPOSE: Children with attention-deficit/hyperactivity disorder (ADHD) often perform poorly during cognitive tests. We sought to evaluate cortisol as potential moderator of performance in mentally challenging tasks in children with ADHD. MATERIALS AND METHODS: Ninety clinic-referred children with ADHD were studied. Cortisol contents in saliva were measured before and after administration of a continuous performance test (CPT). RESULTS: Pre and post CPT cortisol levels were similar in 68 children. Children whose cortisol level increased after testing ( n = 22 ) displayed a significantly longer response time and increased response time variability scores as compared to children who did not display increase of cortisol after the CPT test. Even after controlling for the effects of response time and anxiety, the changes in cortisol levels were associated with effect on response time variability. CONCLUSION: The patients who showed an increased cortisol level after stress displayed a higher variability in response time than the patients who showed no change or a decreased cortisol level. The result of the current study suggests that stress-induced high norepinephrine (NE) release may accompany poorer attention performance in patients with ADHD.