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Biomedical subjects

M D Rapport

Publications and source records attributed to M D Rapport.

34 records · Page 2Linked to original sources
PubMed1988

Attention deficit disorder and methylphenidate: a multi-step analysis of dose-response effects on children's cardiovascular functioning.

The present study investigated the effects of methylphenidate (MPH) on the resting heart rate of 47 children with Attention Deficit Disorder/Hyperactivity. Children participated in a double-blind, placebo control, within subject (cross-over) design and received each of 5 doses of MPH in a counterbalanced sequence. A multi-step analysis was used to examine the dose-response relationship, contribution of pre-stimulus levels of HR (i.e. the initial value), and potential interaction between dosage and time on resting HR. Results indicated that higher dosages are linearly related to increasing levels of HR and that these effects are dependent upon both the initial HR value and the time course of the medication.

Attention Deficit Disorder with Hyperactivity↗
PubMed1988

ADDH and methylphenidate responders: effects on behavior controlled by complex reinforcement schedules.

One of the most effective treatments for children with Attention Deficit Disorder with Hyperactivity (ADDH) has been the prescription of methylphenidate (MPH). While laboratory-based evidence indicates that MPH effects may be rate-dependent, little is known about changes evinced in operant behavior controlled by complex reinforcement schedules. The present study examined the effects of several doses of MPH on the operant key-pressing behavior of 20 children with ADDH who were favorable responders to the drug. Following a drug-free training period, each child performed the task across all doses in a randomly assigned sequence under double-blind placebo control conditions. Rate-dependent effects were found for both high- and low-rate reinforcement schedules. The strength of these effects varied across dose. These results have implications for the nature of rate-dependent phenomena in humans and investigations of treatment parameters in the pharmacotherapy of children with ADDH.

Attention Deficit Disorder with Hyperactivity↗
PubMed1986

Hyperactivity and frustration: the influence of control over and size of rewards in delaying gratification.

This study examined the differential effects of frustration on normal children and those diagnosed as having Attention Deficit Disorder with Hyperactivity. Each group consisted of 16 boys between the ages of 6 and 8 years who were prematched for age, grade, and classroom placement. All children completed a series of arithmetic problems in order to earn toy rewards. Using a variant of Mischel's (1974) delay-of-gratification paradigm, children were presented with two choice-of-delay conditions in a randomly assigned, counterbalanced sequence: a free-choice conflict situation involving a long-passive or short-active reward delay, and a short-active delay. Results showed that a significantly greater proportion of hyperactive children chose to complete problems for an immediate reward compared to their normal control counterparts (p less than .01). Group differences were no longer apparent in the short-active delay trial. The results are discussed in terms of frustration tolerance and contributing factors such as cognitive-attentional style. Implications for treatment and future directions are delineated.

Attention Deficit Disorder with Hyperactivity↗
PubMed1986

Hyperactivity and methylphenidate: rate-dependent effects on attention.

The behavioral effects of CNS stimulants on attention deficit disorder (hyperactive) children's attention are inversely related to their pre-drug rate of behavior, i.e. the effects are rate-dependent. The strength and shape of this relationship are affected by dose and the child's unique reaction to the drug, yet appear unrelated to body weight. Dosage should be directly manipulated in pediatric psychopharmacological studies and the practice of using mg/kg dosage schedules may no longer be necessary.

Attention↗
PubMed1985

Methylphenidate in hyperactive children: differential effects of dose on academic, learning, and social behavior.

Methylphenidate (Ritalin) has been shown to have differential effects on hyperactive children's behavior as a function of dose level. In the present investigation, a triple-blind, placebo-control, within-subject (crossover) experimental design was employed in which 12 hyperactive boys between 6 and 10 years received three different dosages of methylphenidate (5, 10, and 15 mg) in a randomly assigned sequence. Dosage effects were assessed on clinic-(PAL--Paired Associates Learning test) and school-(percent on task, teacher ratings, work completion rates, and accuracy) related behaviors. For 10 of the children, classified as responders to medication by the PAL using the criteria of Swanson, Kinsbourne, and colleagues, a series of ANCOVAs with repeated measures showed significant dosage effects on teacher ratings (p less than .01), percent on task (p less than .01), academic accuracy (p less than .05), and assignment completion rates (p less than .05). PAL performance was also significantly enhanced (p less than .01) after optimal dose levels were considered. Subsequent trend analysis showed a significant positive linear relationship between dose and each of the dependent variables. A comparison of fixed-dose and miligram-per-kilogram plots showed that children's performance across the different dosages were clearly individualistic and task-specific, even when similar body weights were compared. The implications of using clinic-based testing to determine optimal medication responsivity were discussed.

Achievement↗
PubMed1985

Rate-dependency and hyperactivity: methylphenidate effects on operant responding.

The two most common treatment for hyperactivity are psychopharmacological regimens and behavior therapy. Although the concurrent use of stimulant medication has been purported to enhance a child's rate of responding under a behavior management program, studies examining the interaction of the two treatments have been unable to confirm this hypothesis. The present investigation sought to examine the effects of differing levels of methylphenidate hydrochloride (Ritalin) upon operant responding with hyperactive children. After an initial drug-free training period, 10 first through fourth grade hyperactive males performed an operant key-pressing task under a mult VR 5 FI 30 sec reinforcement schedule across four randomly determined, double-blind drug conditions (placebo, 5, 10, 15 mg). Only VR responding changed significantly during medication conditions; however, rate-dependent psychostimulant effects were found within both reinforcement schedules. Discrepancies with animal rate-dependency and implications for treatment and future research are discussed. Medication effects on operant responding appear to depend upon the reinforcement schedule and dose employed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1985

Attention deficit disorder with hyperactivity: differential effects of methylphenidate on impulsivity.

The impulsivity component of attention deficit disorder with hyperactivity requires regulation because its effects interfere with children's school performance and persist into adulthood. The present investigation examined the effects of low to intermediate doses of methylphenidate on impulsivity (measured by the Matching Familiar Figures test, a primary index of cognitive tempo) in 14 children with attention deficit disorder with hyperactivity. The mean percentile error score in the highest dose (15 mg) group was significantly lower than those in placebo (P less than .01), 5-mg (P less than .01), and 10-mg (P less than .01) groups. Trend analysis revealed a linear relationship between dose and error score with total errors decreasing as dose increased. Changes in children's error scores were examined using both fixed-dose and milligram per kilogram data-plotting methods. This work demonstrates the need to consider specific task and child characteristics while assessing the child's responsivity to psychostimulants across a range of safe doses and a variety of behavioral domains.

Attention Deficit Disorder with Hyperactivity↗
PubMed1983

An interdisciplinary approach to the diagnosis and management of a complex case of postencephalitic behavioral disorder.

Postencephalitic behavioral syndrome secondary to measles is an almost extinct condition in Western culture. The present paper describes the clinical state of a 13-year-old pubertal female who presented nine years after the original acute febrile illness. In addition, an innovative behavioral approach to treatment of intractable seizures and aggressive behavior is described.

Adolescent↗
PubMed1982

Ritalin vs. response cost in the control of hyperactive children: a within-subject comparison.

A within-subject comparison was made of the effects of methylphenidate (Ritalin) and response cost in reducing the off-task behavior of two boys, 7 and 8 years of age, who had been diagnosed as having an attentional deficit disorder with hyperactivity, Several dosages of Ritalin (5 to 20 mg/day) were evaluated with the results indicating varying effects of the drug for both children. Response cost (with free-time as the reinforcer) was superior to Ritalin in raising levels of on-task behavior and in improving academic performance.

Achievement↗
PubMedDate not supplied

The fear survey schedule for children-revised (FSSC-HI): ethnocultural variations in children's fearfulness.

A revised Fear Survey Schedule for Children was used to examine the structure and developmental pattern of fearfulness in an ethnoculturally diverse sample of 385 Hawaii schoolchildren aged 7 to 16 years. The instrument's psychometric properties compared favorably with previous versions of the FSSC, and a 7-factor solution provided the best conceptual fit for the data. Six factors were similar to those described in previous versions of the FSSC, whereas the seventh was unique, reflecting children's social conformity fears. Between-group comparisons revealed significantly less fearfulness in children of Caucasian than of Asian, Filipino, and Hawaiian ethnocultural backgrounds. Gender and age differences were similar to previous reports in finding greater fearfulness in girl than boys, and in younger than older children on most factors. Results corroborate previous reports concerning gender and age trajectories of fearfulness and indicate that culture may mediate the expression of fears in culturally diverse populations.

Adolescent↗
PubMedDate not supplied

Attention deficit disorder and methylphenidate: normalization rates, clinical effectiveness, and response prediction in 76 children.

OBJECTIVE: To evaluate the magnitude and clinical significance of methylphenidate (MPH) effects on the classroom behavior and academic performance of 76 children with attention deficit disorder/hyperactivity (ADDH). METHOD: A double-blind, placebo controlled, within-subject (crossover) experimental design was used to evaluate acute MPH effects at four dose levels (5 mg, 10 mg, 15 mg, and 20 mg) on children's attention, academic functioning, and behavior in regular classroom settings. Results were contrasted with a normal control sample. RESULTS: Standard statistical analysis revealed MPH effects on classroom functioning that were primarily linear. Analysis of the clinical significance of effects indicated that large proportions of treated children exhibited significantly improved or normalized classroom functioning; however, a large subset of them failed to show improved academic functioning. Overall, children failing to respond at lower dose levels have a high probability of improving or becoming normalized as a function of increasing dose. CONCLUSIONS: For a majority of children with ADDH, MPH results in significantly improved or normalized attention and classroom behavior. A significant subset, however, fail to realize gains in their academic functioning and will require supplemental interventions.

Achievement↗