ABSTRACT
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.
Subject(s)
Adolescent , Child , Female , Humans , Male , Attention Deficit Disorder with Hyperactivity/metabolism , Hydrocortisone/metabolism , Norepinephrine/metabolism , Reaction Time/physiology , Saliva/chemistry , Stress, Psychological/physiopathologyABSTRACT
PURPOSE: Methylphenidate (MPH) is an effective medication for the treatment of attention deficit hyperactivity disorder (ADHD). However, about 30% of patients do not respond to or are unable to tolerate MPH. Based on previous findings, we hypothesized that great variability in response time (RT) among Korean children with ADHD on a computerized continuous performance attention test would be related to poor MPH treatment response. MATERIALS AND METHODS: Children (ages 6-18 years) with ADHD were recruited for a prospective 12-week, open-labeled, multicenter study to examine optimal dosage of OROS methylphenidate. Of the 144 subjects selected, 28 dropped out due to adverse events, medication noncompliance, or follow-up loss, and an additional 26 subjects with comorbid disorders were excluded from statistical analyses. We defined 'responders' as subjects who received a score of less than 18 on the attention deficit hyperactivity disorder rating scale (ARS; Korean version, K-ARS) and a score of 1 or 2 on the Clinical Global Impression-Improvement scale (CGI-I). RT variability was assessed with the ADHD diagnostic system (ADS). RESULTS: Fifty-nine (67%) subjects responded to MPH treatment. The non-responders showed greater RT variability at baseline (Mann Whitney U = 577.0, p < 0.01). Baseline RT variability was a significant predictor of MPH response (Nagelkerke R2 = 0.136, p < 0.01). It predicted 94.9% of responder, 17.2% of non-responder and 69.3% of overall group. CONCLUSION: High RT variability may predict poor response to MPH treatment in children with ADHD.
Subject(s)
Adolescent , Child , Female , Humans , Male , Attention Deficit Disorder with Hyperactivity/drug therapy , Korea , Methylphenidate/therapeutic use , Reaction Time , Treatment OutcomeABSTRACT
OBJECTIVES: For the past half century, lithium has been used for the acute and prophylactic treatment of bipolar disorder and recurrent depression. Recently, new pharmacological effects of Li+ have appeared, showing that Li+ can influence neuronal injury. We tested the effects of Li+ on free radical induced neuronal injury in primary murine cortical cell cultures. METHODS: Cortical cells were prepared from fetal mice (embryonic day 15) and exposed to 30 micrometer Fe2+ alone or with 5 mM Li+ or 5 mM Li+ alone for 24 hrs at Days in vitro (DIV) 14. Neuronal death was analyzed by measuring lactate dehydrogenase (LDH) release into media. The fluorescence of 2',7'-dichlorofluorescin (DCF) was measured in as a mean of estimating the formation of reactive oxygen species (ROS). RESULTS: Li+ alone does not produce neuronal injury itself but it potentiates Fe2+-induced neuronal injury through increasing the production of free radical. CONCLUSION: This study suggests that the effects of Li+ on neuronal survivorship may be injury type dependent and Li+ potentiate the free radical injury. Therefore in practice clinician should be cautious in using the lithium in the treatment of brain injured patients.