Crossover Study Of Methylphenidate Research Articles

A Randomized, Double-Blind, Crossover Study of Methylphenidate and Lithium in Adults With Attention-Deficit/Hyperactivity Disorder: Preliminary Findings

The authors examined the efficacy of methylphenidate (MPH) and lithium to treat attention-deficit/ hyperactivity disorder (ADHD) in adults, using a randomized, double-blind, crossover design. Patients received 8 weeks of MPH treatment (up to 40 mg/day) and 8 weeks of lithium treatment (up to 1,200 mg/day), by random assignment. Independent evaluators blind to group assignment assessed response every 2 weeks and at the end of each phase. The primary outcome measure was the Conners' Adult ADHD Rating Scale sum score for the clusters of hyperactivity, impulsivity, and learning problems. Secondary outcome measures were scores of irritability, overt aggression, antisocial behavior, anxiety, and depression, and scores on tests of verbal learning and sustained attention. In this preliminary study, lithium and MPH produced similar improvements on the primary outcome measure and on measures of irritability, aggressive outbursts, antisocial behavior, anxiety, and depression.

Trial of Methylphenidate and Thioridazine

A double-blind, placebo-controlled, cross-over study of methylphenidate (0.4 mg/kg/day) and thioridazine (1.75 mg/kg/day) in 27 intellectually subaverage children is reported from The Nisonger Center for Mental Retardation and Developmental Disabilities, Ohio State Univ., Columbus, OH, and the University of Aukland, New Zealand.

Methylphenidate and thioridazine in the treatment of intellectually subaverage children: Effects on cognitive-motor performance

Twenty-seven children (or smaller subgroups depending upon task difficulty and subject ability) with subaverage IQs took part in a double-blind, placebo-controlled, cross-over study of methylphenidate (0.4 mg/ kg/day) and thioridazine (1.75 mg/kg/day). The children were tested for IQ performance, breadth of attention, and performance on a series of electronically controlled cognitive-motor tests. Methylphenidate improved accuracy on a memory task, reduced omission errors on an attentional task, and reduced seat movements on two tasks. Thioridazine failed to have any deleterious effects on IQ performance when subjects received reinforcers for correct answers. Thioridazine at the given dose did not adversely affect performance on any of the cognitive-motor performance tests. Methylphenidate appears likely to enhance sustained attention and motivation in appropriately selected children with mild developmental delays, whereas thioridazine at this modest dose does not appear to impair performance on most psychomotor tests.

Growth hormone and prolactin secretion in adults and hyperactive children: Relation to methylphenidate serum levels

The effect of a single dose of oral methylphenidate (MPH) on blood levels of growth hormone (GH) and prolactin (PRL) was measured in 27 hyperactive children (HKC), eight ‘hyperactive’ adults and eight normal adults in two experimental paradigms: a double-blind crossover study of MPH in a single dose (0.3 mg/kg) and a double-blind crossover study of MPH at two dose levels (0.3 and 0.6 mg/kg). In all groups in both studies, a consistent and statistically significant increase in circulating GH concentrations was observed; in HKC, this increase was dose-related. Also, in all groups in both studies there was a consistent decrease in circulating PRL concentrations. This change was significant in the adults at the 0.3 mg/kg dose, but in the children only at the 0.6 mg/kg dose. The increase in GH correlated with MPH serum levels in both the HKC and the adults. The decrease in PRL correlated with MPH serum levels only in the adults.

HYPERKINESIS, AUTONOMIC NERVOUS SYSTEM ACTIVITY AND STIMULANT DRUG EFFECTS

SummaryThis study focused on the degree to which resting levels of autonomic “arousal” were related to hyperkinetic behaviors and stimulant drug responses. A total of 24 boys served as subjects, 12 of whom were hyperkinetic and had a history of responding well to methylphenidate while 12 normal boys served as a matched control group. The control boys were evaluated once while the hyperkinetic boys were seen on three occasions during which they participated in a double‐blind, placebo‐controlled crossover study of methylphenidate. All children were evaluated using five psycho‐physiological measures of autonomic nervous system activity and 11 objective measures of activity level and attention taken across four experimental settings. Results indicated no significant differences between hyperkinetic and normal boys in psychophysiological activity. In addition, no consistent relationships between this activity and the objective behavioral measures in either normal or hyperkinetic boys were observed. Improvements in activity level and attention during drug treatment were generally not related to the pretreatment levels of arousal in the hyperkinetic boys. Methylphenidate did not produce any significant effects on autonomic activity. Thus, results suggested that no simple level of arousal hypothesis can account for the behavior patterns of hyperkinetic children and that level of arousal is not a particularly useful predictor of drug responding in these children.