Sense of time in children with ADHD: effects of duration, distraction, and stimulant medication.

A recent theory of ADHD predicts a deficiency in sense of time in the disorder. Two studies were conducted to test this prediction, and to evaluate the effects of interval duration, distraction, and stimulant medication on the reproductions of temporal durations in children with ADHD. Study I: 12 ADHD children and 26 controls (ages 6-14 years) were tested using a time reproduction task in which subjects had to reproduce intervals of 12, 24, 36, 48, and 60 s. Four trials at each duration were presented with a distraction occurring on half of these trials. Control subjects were significantly more accurate than ADHD children at most durations and were unaffected by the distraction. ADHD children, in contrast, were significantly less accurate when distracted. Both groups became less accurate with increasing durations to be reproduced. Study II: Tested three doses of methylphenidate (MPH) and placebo on the time reproductions of the 12 ADHD children. ADHD children became less accurate with increasing durations and distraction was found to reduce accuracy at 36 s or less. No effects of MPH were evident. The results of these preliminary studies seem to support the prediction that sense of time is impaired in children with ADHD. The capacity to accurately reproduce time intervals in ADHD children does not seem to improve with administration of stimulant medication.

Response of children with ADHD to methylphenidate: interaction with internalizing symptoms.

OBJECTIVE: The purpose of this study was to examine differences in methylphenidate (MPH) response between groups of children with attention-deficit hyperactivity disorder (ADHD) who exhibited varying degrees of internalizing symptoms. METHOD: A sample of 40 children with ADHD was subdivided into three groups based on the severity of comorbid internalizing symptoms. Differential effects of three doses of MPH (5 mg, 10 mg, 15 mg) were evaluated in a double-blind, placebo-controlled fashion using multiple outcome measures across home, school, and clinic settings. RESULTS: Children with ADHD and comorbid internalizing symptoms were significantly less likely to respond positively to MPH than were their noninternalizing counterparts according to teacher ratings and behavioral observations during a clinic-based academic task. CONCLUSIONS: Children who exhibit comorbid symptoms of ADHD and internalizing disorder are less likely to respond to MPH in classroom settings and on academic tasks. A significant minority of children with comorbid conditions may be at a higher risk for an adverse medication response relative to patients with ADHD who are not exhibiting internalizing symptoms. Further research is necessary to delineate the characteristics of possible adverse responders.

Attention deficit disorder with and without hyperactivity: clinical response to three dose levels of methylphenidate.

The response of 23 children with attention deficit disorder (ADD) with hyperactivity (+H) and 17 children with ADD without hyperactivity (-H) to three doses of methylphenidate (5, 10, and 15 mg twice a day) was evaluated in a triple-blind, placebo-controlled cross-over design using parent and teacher ratings of behavior, laboratory tests of ADD symptoms, and behavioral observations during academic performance. Results indicated that the children with ADD+H were rated as having more pervasive behavioral problems at home and more pervasive and severe conduct problems at school than the children with ADD-H. Laboratory tests found the children with ADD+H to be impaired in behavioral inhibition and vigilance whereas children with ADD-H were more impaired in the consistent retrieval of verbally learned material Drug effects were noted on the parent and teacher ratings and on most laboratory measures, with all three doses typically producing significant changes but rarely differing among themselves in effectiveness. The groups were not found to differ significantly on any measures in their response to methylphenidate. However, more children with ADD-H were clinically judged as having either no clinical response (24%) or responding best to the low dose (35%) of medication. In contrast, most ADD+H (95%) children were judged to be positive responders and most were recommended to receive the moderate to high dose (71%).

Comprehensive evaluation of attention deficit disorder with and without hyperactivity as defined by research criteria.

Children with attention deficit disorder with hyperactivity (ADD+H; N = 48) were compared with those without hyperactivity (ADD-H; N = 42), as well as with learning disabled and control children, on an extensive battery of interviews, behavior ratings, tests, and direct observations. ADD+H children had more externalizing and internalizing symptoms by parent and teacher report, were more off task during vigilance testing, and had more substance abuse, ADD+H, and aggression among their relatives than did the other groups. ADD-H children were more day-dreamy and lethargic by teacher report, more impaired in perceptual-motor speed, and had more anxiety disorders among their relatives than did ADD+H children. Results indicate that these 2 types of ADD may be separate, distinct childhood disorders rather than subtypes of a common attention deficit.

Side effects of methylphenidate in children with attention deficit hyperactivity disorder: a systemic, placebo-controlled evaluation.

The frequency and severity of 17 side effects presumably associated with stimulant medication were assessed during a rigorous, triple-blind, placebo-controlled, crossover evaluation of methylphenidate, 0.3 and 0.5 mg/kg twice a day, in 83 children with attention deficit hyperactivity disorder. Side effects were rated by parents and teachers at the end of each weekly drug condition. Three children (3.6%) had side effects that were sufficiently serious to warrant immediate discontinuation of medication. Parent ratings indicated that only the side effects of decreased appetite, insomnia, stomachaches, and headaches increased significantly in frequency and severity during the two active medication doses as compared with the placebo condition. Fewer than half of the children experienced these side effects and among those who did, ratings of mean severity remained in the mild range. Teacher ratings showed little change over drug conditions, except on ratings of staring, sadness, and anxiety, which declined with increasing dose of medication. Parent ratings indicated that only the side effects of decreased appetite, insomnia, stomachaches, and headaches increased significantly in frequency and severity during the two active medication doses as compared with the placebo condition. Fewer than half of the children experienced these side effects and among those who did, ratings of mean severity remained in the mild range. Teacher ratings showed little change over drug conditions, except on ratings of staring, sadness, and anxiety, which declined with increasing dose of medication. Surprisingly, a high frequency of these behavior side effects were reported during the placebo condition. Stimulant medication within this therapeutic range, therefore, results in few, generally mild side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

The response of aggressive and nonaggressive ADHD children to two doses of methylphenidate.

Differences between 37 aggressive and 37 nonaggressive children with attention deficit hyperactivity disorder (ADHD) were evaluated as was their response to two doses of methylphenidate (0.3 and 0.5 mg/kg) using a multimethod battery of behavior ratings, laboratory tests, and direct observations. Aggressive ADHD children differed little from nonaggressive ADHD children except that nonaggressives displayed more problems with inattentiveness at school than aggressives while mothers of aggressives reported more symptoms of psychopathology in themselves than mothers of nonaggressives. In their drug responding, aggressives and nonaggressives were quite similar. The few exceptions were on measures of conduct, on which the aggressives were initially rated as more extreme and subsequently showed the greater degree of improvement from medication than nonaggressives. Results replicated those of a previous study and further indicate that aggressive and nonaggressive ADHD children share a common disorder of ADHD but aggressives have more impaired family situations.