PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “METHYLPHENIDATE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

NTP-CERHR monograph on the potential human reproductive and developmental effects of methylphenidate.

The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for methylphenidate to cause adverse effects on reproduction and development in humans. Methylphenidate was selected for evaluation because of 1) widespread usage in children, 2) availability of developmental studies in children and experimental animals, and 3) public concern about the effect of this stimulant on child development. Methylphenidate is a central nervous system stimulant approved by the U.S. Food and Drug Administration for the treatment of attention deficit hyperactivity disorder (ADHD) in persons 6 years of age and older and for narcolepsy. The results of this evaluation on methylphenidate are published in an NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of Methylphenidate, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to methylphenidate on human development and reproduction. First, there is negligible concern for methylphenidate-induced tics and movement disorders. This conclusion is based on studies showing that children treated with therapeutic doses of methylphenidate have no evidence of movement disorders or tics due to the medication. Second, there is minimal concern for methylphenidate-induced growth restriction. This conclusion is based on growth restriction being observed in animal studies only at high doses of methylphenidate using a non-therapeutic route of exposure. The effect on growth was reversible. Finally, there are insufficient data to draw conclusions on 1) an association between methylphenidate therapy in pregnant women and pregnancy loss and 2) possible reproductive effects of methylphenidate in humans. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available in electronic PDF format on the CERHR web site http://cerhr.niehs.nih.gov/ and in printed text or CD-ROM from the CERHR.

Animals↗

Epilepsy and attention deficit hyperactivity disorder: is methylphenidate safe and effective?

OBJECTIVE: To study the safety and efficacy of methylphenidate in children with the dual diagnosis of epilepsy and attention deficit hyperactivity disorder (ADHD). STUDY DESIGN: Thirty children, aged 6.4 to 16.4 years, with epilepsy and ADHD were studied during a 4-month period. During the initial 2 months of the study, the children were treated with antiepileptic drugs (AEDs) only, and for the remaining 2 months, methylphenidate was added at a morning dose of 0.3 mg/kg. They underwent neurologic assessment, brain computed tomography, IQ testing, and assessment with the Childhood Behavior Checklist at baseline before methylphenidate therapy. Electroencephalography, AED determinations, and the continuous-performance task (CPT) test were done at baseline and after 2 months of methylphenidate therapy. A double-blind, crossover design was used to compare the effects of methylphenidate versus placebo on an electroencephalogram, AED levels, and the CPT. On the 2 days of testing, the child received AEDs and a capsule containing either placebo or methylphenidate. RESULTS: None of the 25 children of this sample who were seizure free had attacks while taking methylphenidate. Of the 5 children with seizures, 3 had an increase in attacks, whereas the other 2 showed no change or a reduction. There were no significant changes in AED levels or electroencephalographic findings. Methylphenidate benefited 70% of children according to parental report; methylphenidate also enhanced performance on the CPT. Side effects of methylphenidate were mild and transient. CONCLUSION: Methylphenidate is effective in treating children with epilepsy and ADHD and safe in children who are seizure free. Caution is warranted for those still having seizures while receiving AED therapy.

Adolescent↗

Epilepsy and attention deficit hyperactivity disorder: is methylphenidate safe and effective?

OBJECTIVE: To study the safety and efficacy of methylphenidate in children with the dual diagnosis of epilepsy and attention deficit hyperactivity disorder (ADHD). STUDY DESIGN: Thirty children, aged 6.4 to 16.4 years, with epilepsy and ADHD were studied during a 4-month period. During the initial 2 months of the study, the children were treated with antiepileptic drugs (AEDs) only, and for the remaining 2 months, methylphenidate was added at a morning dose of 0.3 mg/kg. They underwent neurologic assessment, brain computed tomography, IQ testing, and assessment with the Childhood Behavior Checklist at baseline before methylphenidate therapy. Electroencephalography, AED determinations, and the continuous-performance task (CPT) test were done at baseline and after 2 months of methylphenidate therapy. A double-blind, crossover design was used to compare the effects of methylphenidate versus placebo on an electroencephalogram, AED levels, and the CPT. On the 2 days of testing, the child received AEDs and a capsule containing either placebo or methylphenidate. RESULTS: None of the 25 children of this sample who were seizure free had attacks while taking methylphenidate. Of the 5 children with seizures, 3 had an increase in attacks, whereas the other 2 showed no change or a reduction. There were no significant changes in AED levels or electroencephalographic findings. Methylphenidate benefited 70% of children according to parental report; methylphenidate also enhanced performance on the CPT. Side effects of methylphenidate were mild and transient. CONCLUSION: Methylphenidate is effective in treating children with epilepsy and ADHD and safe in children who are seizure free. Caution is warranted for those still having seizures while receiving AED therapy.

Adolescent↗

Transdermal iontophoretic delivery of methylphenidate HCl in vitro.

Methylphenidate is prescribed orally for Attention Deficit Disorder in children and adults, and for narcolepsy patients. Methylphenidate has a short plasma half-life (1-2 h) and thus needs to be frequently administered for effective therapy. Such therapy has limitations in terms of patient compliance, particularly in young children. For such reasons, the development of a transdermal dosage form of methylphenidate may be useful. This study was undertaken to evaluate the passive and electrically assisted transport (iontophoresis) of methylphenidate from aqueous methylphenidate hydrochloride solutions across excised human skin. A maximum flux of 12.0 micrograms/(cm2 h) of protonated methylphenidate was estimated from the passive transport data at pH 3.5. Iontophoresis significantly enhanced protonated methylphenidate transport as compared with passive delivery. From the present experiments, the efficiency of iontophoretic delivery of methylphenidate was approximately 700 micrograms/(mA h). Based on in vitro skin flux data, the daily dose of 15-40 mg methylphenidate can be achieved using a current density of 0.5 mA/cm2 and a minimum transport area of 2-5 cm2 for 24-h application, or an area of 4-10 cm2 for 12-h (daytime) application. From methylphenidate skin flux values, methylphenidate mobility of 2.2 x 10(-4) cm2/(V s) was estimated, which compares reasonably with its free solution mobility of 6.6 x 10(-4) cm2/(V s).

Administration, Cutaneous↗

Daily methylphenidate administration attenuates c-fos expression in the striatum of prepubertal rats.

Methylphenidate (Ritalin) is a psychostimulant drug used to treat children with attention deficit hyperactivity disorder. Despite its widespread and increasing clinical use, little is known about the long-term consequences of drug treatment. We compared the effects of a single injection of methylphenidate with that of long-term methylphenidate injections (one/day; 14 days) on immediate-early gene expression (c-fos) in the striatum of prepubertal male rats. Rats (25 days old) were injected once daily for 14 days with either saline or methylphenidate (1, 2 or 10 mg/kg), or for 13 days with saline followed by one injection of methylphenidate (1, 2 or 10 mg/kg) on day 14, and were sacrificed 2 h post-injection. Methylphenidate dose-dependently increased FOS immunoreactivity in the striatum. A single injection of methylphenidate (2 or 10 mg/kg) on day 14, following saline treatment for 13 days, caused a dramatic elevation in c-fos expression. This effect was significantly attenuated in animals treated chronically with methylphenidate (2 or 10 mg/kg) for the entire 14 days. Our data suggest that repeated methylphenidate treatment, at a clinically relevant dose (2 mg/kg), markedly inhibits immediate-early gene expression in the brain. This is the first demonstration of methylphenidate-induced modification of gene expression in developing rat striatum and may have implications for chronic methylphenidate use in children.

Animals↗

Dopamine transporter occupancies in the human brain induced by therapeutic doses of oral methylphenidate.

OBJECTIVE: The therapeutic effects of methylphenidate in the treatment of attention deficit disorder have been attributed to its ability to increase the synaptic concentration of dopamine by blocking the dopamine transporters. However, the levels of dopamine transporter blockade achieved by therapeutic doses of methylphenidate are not known. This study measured, for the first time, dopamine transporter occupancy by orally administered methylphenidate in the human brain and its rate of uptake in the brain. METHOD: Positron emission tomography (PET) and [11C]cocaine were used to estimate dopamine transporter occupancies after different doses of oral methylphenidate in seven normal subjects (mean age=24 years, SD=7). In addition, the pharmacokinetics of oral methylphenidate were measured in the baboon brain through use of PET and [11C]methylphenidate administered through an orogastric tube. RESULTS: At 120 minutes after administration, oral methylphenidate produced a dose-dependent blockade of dopamine transporter; means=12% (SD= 4%) for 5 mg, 40% (SD=12%) for 10 mg, 54% (SD=5%) for 20 mg, 72% (SD=3%) for 40 mg, and 74% (SD=2%) for 60 mg. The estimated dose of oral methylphenidate required to block 50% of the dopamine transporter corresponded to 0.25 mg/kg. Oral methylphenidate did not reach peak concentration in brain until 60 minutes after its administration. CONCLUSIONS: Oral methylphenidate is very effective in blocking dopamine transporters, and at the weight-adjusted doses used therapeutically (0.3 to 0.6 mg/kg), it is likely to occupy more than 50% of the dopamine transporters. The time to reach peak brain uptake for oral methylphenidate in brain corresponds well with the reported time course to reach peak behavioral effects.

Administration, Oral↗

[Influence of methylphenidate on growth of school age children with attention deficit hyperactivity disorder].

OBJECTIVE: To determine whether long-term treatment of attention deficit hyperactivity disorder (ADHD) with methylphenidate influences the growth in height and weight of children. METHODS: Analyses were performed on 146 school age children (126 boys) diagnosed as ADHD and treated with methylphenidate [0.27-0.64 mg/(kg.day)] for methylphenidate group and 29 children with ADHD who did not receive any medication for ADHD (controls). These children were followed-up for 2-4 years. Changes in height and weight after long-term treatment with methylphenidate were recorded and the factors affecting growth of height, weight, and height velocity were analyzed. RESULTS: The change of difference between patients' height and mean height in methylphenidate group and controls was (-1.86 +/- 0.82) cm (paired t test, t = 27.335, P < 0.001) and (-0.26 +/- 0.51) cm (P < 0.05), respectively; the change of height standard deviation score (SDS) in methylphenidate group and controls was -0.14 +/- 0.23 SD (paired t test, t = 7.326, P < 0.001) and +0.05 +/- 0.10 SD (P < 0.05), respectively. When the height change and height SDS change in methylphenidate group and controls were compared by using independent-samples T-test, the t value was -10.078 and -4.262 respectively, P for both was < 0.001. Both of bivariate correlation analysis and stepwise multiple-regression analysis indicated that the duration of treatment contributed significantly to the variance in change of height (P < 0.001); but age, sex, DSM-IV type, NJ22 degree and dose of methylphenidate did not contribute significantly to the variance of height. The mean height velocity from 1st to 4th year was 4.28 cm/year, 4.90 cm/year, 4.98 cm/year and 4.95 cm/year, respectively. With Friedman test, Chi-square = 253.673, P < 0.001. The change of difference of patients' weight to weight for height after methylphenidate was (-0.14 +/- 1.25) kg (paired t test, t = 1.326, P > 0.05). CONCLUSION: Small but significant deceleration of height velocity is the identified long-term side effect of methylphenidate, the magnitude of height deficit is related to duration of treatment. The height velocity was significantly attenuated in the first year. Methylphenidate had no significant influence on weight.

Attention Deficit Disorder with Hyperactivity↗

The use of methylphenidate in Michigan.

OBJECTIVE: To describe the epidemiologic findings associated with the use of methylphenidate hydrochloride among children aged 0 to 19 years in Michigan. DESIGN: A population-based data set of all prescriptions filed with the Michigan Triplicate Prescription Program during February and March 1992 was analyzed, maintaining complete anonymity. SETTING: State of Michigan. PARTICIPANTS: All patients receiving a prescription for methylphenidate who are residents of Michigan, and all physicians prescribing methylphenidate. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Descriptive data. RESULTS: Eleven of 1000 Michigan residents between the ages of 0 and 19 years received a prescription for methylphenidate during the study period. Eighty-four percent were boys. Boys aged 10 or 11 years received more prescriptions for methylphenidate than any other age group--43 per 1000. The number of children receiving prescriptions for methylphenidate ranged from 2.5 to 28 per 1000. The range for boys aged 10 or 11 years was from 9.6 to 117 per 1000. Primary care physicians wrote 84% of all prescriptions; pediatricians wrote 59% of the prescriptions for patients younger than 20 years old. Half of the prescriptions written by pediatricians were written by 5% of the pediatricians in the state. CONCLUSIONS: Michigan has been among the states with the highest per capita consumption of methylphenidate for the past 10 years. The major use of methylphenidate is for treatment of attention deficit hyperactivity disorder. The number of boys in Michigan aged 10 or 11 years who were treated with methylphenidate was similar to the national prevalence of the disorder, 3% to 5%. A tenfold variation was noted in the percentage of children medicated when the data were analyzed by county. Relatively few pediatricians account for the largest proportion of prescriptions. Future studies are needed to link the use of methylphenidate with diagnostic and treatment considerations in attention deficit hyperactivity disorder.

Adolescent↗

Single-dose pharmacokinetics of modafinil and methylphenidate given alone or in combination in healthy male volunteers.

Modafinil is a novel wake-promoting agent being developed for treatment of excessive daytime sleepiness associated with narcolepsy. An open, 3 x 3 Latin square, randomized, cross-over study was performed in healthy males to compare the pharmacokinetics of single-dose oral modafinil (200 mg) and methylphenidate (40 mg) administered alone or in combination. Blood samples were obtained for analysis of d- and l-threo-methylphenidate and modafinil and its acid and sulfone metabolites. Pharmacokinetic parameters were determined by noncompartmental methods, but could not be evaluated for modafinil sulfone due to plasma levels that were close to the assay quantitation limit. Although sporadic differences in plasma concentrations were observed between treatments, coadministration of modafinil and methylphenidate did not significantly alter the plasma concentrations of modafinil, modafinil acid, modafinil sulfone, or methylphenidate enantiomers compared with administration of these agents alone. Half-life (t1/2), maximum concentration (Cmax), area under the concentration-time curve (AUC0-infinity), total clearance (Cl/F), and apparent volume of distribution (Vd/F) for modafinil and t1/2, Cmax, and AUC0-infinity for modafinil acid were not affected by concomitant administration of methylphenidate. Small but statistically significant increases in time to Cmax (tmax) were observed for modafinil and modafinil acid after methylphenidate coadministration compared with modafinil alone. Modafinil coadministration did not significantly alter the pharmacokinetics of d- or l-threo-methylphenidate, except for a small decrease in Vd/F of l-threo-methylphenidate. Concomitant methylphenidate may cause a delay in the oral absorption of modafinil, but this delay might not be relevant clinically. Coadministration did not alter the extent of oral absorption and disposition of either agent. Therefore, a pharmacokinetic interaction between modafinil and methylphenidate would be unlikely.

Adolescent↗

Effects of methylphenidate on impulsive choice in adult humans.

RATIONALE: Several studies with nonhumans and humans have shown that stimulants decrease impulsive choices on delay-to-reinforcement (self-control) procedures. Little is known, however, about the effects of the stimulant methylphenidate on choice for delayed reinforcers in humans. OBJECTIVES: The present study was designed to investigate the effects of acute methylphenidate administrations on impulsive responding in adult humans on a delay-to-reinforcement task. METHODS: Eleven adult males with a history of criminal behavior but no history of attention-deficit hyperactivity disorder (ADHD) participated. Impulsive responding was measured using an adjusting-delay procedure in which subjects were presented with repeated choices between a small amount of money delivered after a short delay and a larger amount of money delivered after a delay that adjusted as a function of previous choices. Subjects were exposed to four experimental sessions each day of participation and 60 min prior to the first daily session received placebo or 0.15, 0.30, or 0.60 mg/kg methylphenidate. Stable choice patterns were re-established between each methylphenidate dose. RESULTS: Individuals differed in their sensitivity to methylphenidate, but in over half of the subjects methylphenidate decreased impulsive (i.e., increased the number of self-control choices) and increased the delay to the large reinforcer. The largest increases in self-control choices tended to occur at the 0.30-mg/kg and 0.60-mg/kg doses, and the effects often persisted across multiple daily sessions. In six subjects, under at least one methylphenidate dose, the number of impulsive choices decreased to zero. CONCLUSIONS: Acute methylphenidate administrations tended to decrease the number of impulsive choices in adult humans on an adjusting-delay procedure, although there were substantial individual differences in the sensitivity of choice to methylphenidate. In no case, however, did methylphenidate increase impulsive choices. These results are consistent with several recent laboratory studies with nonhumans and humans showing that stimulants increase preference for large, delayed reinforcers.

Adolescent↗

Age and sex differences in the locomotor effect of repeated methylphenidate in rats classified as high or low novelty responders.

RATIONALE: Rats displaying high levels of activity in an inescapable novel environment (high responders; HR) are more sensitive to the locomotor effect of stimulant drugs than rats displaying low levels of activity (low responders; LR). OBJECTIVE: The current study determined the age- and sex-dependent locomotor effects of repeated methylphenidate in HR and LR rats. MATERIALS AND METHODS: Periadolescent and adult male and female Sprague-Dawley rats were first classified as HR or LR; rats were also classified as high or low novelty seekers based on free-choice preference for a novel environment. Locomotor activity was subsequently assessed after ten daily injections of methylphenidate (3 or 10 mg/kg s.c.) or saline. Fifteen days later, rats were challenged with saline and methylphenidate (10 mg/kg) over 2 days. RESULTS: During the repeated methylphenidate treatment phase, adult females showed greater methylphenidate-induced hyperactivity than adult males; there was no reliable difference in methylphenidate-induced hyperactivity between HR and LR rats of either age or sex. However, periadolescent male HR rats given repeated methylphenidate showed greater conditioned hyperactivity after the saline challenge than periadolescent male LR rats. Further, adult female HR rats given repeated methylphenidate showed greater conditioned hyperactivity and sensitization than adult female LR rats. In contrast, although free-choice novelty preference was greater among periadolescents than adults, individual differences in this variable did not predict the effect of repeated methylphenidate during any phase of the experiment. CONCLUSION: Although individual differences in response to inescapable novelty predict methylphenidate-induced conditioned hyperactivity and sensitization, this relationship is moderated by age and sex.

Age Factors↗

Methylphenidate-induced hepatotoxicity in mice and its potentiation by beta-adrenergic agonist drugs.

Methylphenidate hydrochloride, when administered as a single 75 to 100 mg/kg i.p. dose, was found to produce hepatic necrosis in male ICR mice. Peak hepatotoxicity, as measured by serum ALT elevations, occurred 16 hours post-treatment while maximal histopathological evidence of hepatotoxicity occurred 24-48 hours after the methylphenidate dose. Liver injury measured by either method was essentially nonexistent for dosages < or = 50 mg/kg in male mice, and was only minimally evident in female mice at the highest dosage testable. Co-treatment of mice with either alpha 1- or alpha 2-adrenergic agonist drugs had no meaningful effect on methylphenidate-induced hepatotoxicity. In contrast, the beta-adrenergic agonist drug isoproterenol produced a striking potentiation of the liver injury, and shifted the apparent threshold for toxicity approximately 5- to 10-fold. Co-administration of methylphenidate with the mixed alpha/beta-adrenergic agonist dobutamine or with the beta 2-selective agonists metaproterenol, ritodrine or terbutaline produced a similar potentiation of toxicity. Parallel tests with beta-adrenergic antagonists revealed that the potentiation by isoproterenol could be significantly diminished by a single dose of the non-selective beta-adrenoreceptor blocking drug nadolol or the beta 2-selective antagonist ICI-118,551, but not the beta 1-selective antagonist metoprolol. Collectively, these observations suggest that potentiation of methylphenidate hepatotoxicity occurs through stimulation of beta 2-adrenoreceptors. Mice co-treated with isoproterenol were found to have substantially higher serum and liver methylphenidate levels following the methylphenidate dose, and significant increases were also observed in the area-under-the-curve (AUC) for methylphenidate in both tissues of isoproterenol co-treated mice. The results of this study suggest that beta 2-adrenergic agonist drugs are capable of potentiating methylphenidate-induced hepatotoxicity in mice by increasing hepatic methylphenidate concentrations.

Adrenergic alpha-Agonists↗

Effects of expectation on the brain metabolic responses to methylphenidate and to its placebo in non-drug abusing subjects.

The response to drugs is affected by expectation, which in turn is sensitive to prior drug experiences. Here, we evaluate the effects of expectation on the responses to intravenous methylphenidate (0.5 mg/kg) in fifteen subjects who had minimal experience with stimulant drugs. We used positron emission tomography to measure brain glucose metabolism, which we used as a marker of brain function and tested them under four randomized conditions (1) expecting placebo and receiving placebo; (2) expecting placebo and receiving methylphenidate; (3) expecting methylphenidate and receiving methylphenidate; (4) expecting methylphenidate and receiving placebo. We show that methylphenidate-induced decreases in striatum were greater when subjects expected to receive methylphenidate than when they were not expecting it. We also show that the subjects' expectations affected their responses to placebo. That is, when subjects expected to receive methylphenidate but received placebo there were significant increases in ventral cingulate gyrus (BA 25) and nucleus accumbens (regions involved with emotional reactivity and reward). The effect was largest in subjects who, because of experimental randomization, had not experienced methylphenidate. Because subjects were told that methylphenidate could be experienced as pleasant, unpleasant or devoid of subjective effects these results suggest the involvement of the ventral cingulate and of the nucleus accumbens in processing expectation for "uncertain drug effects". Thus, the state of expectation needs to be considered as a variable modulating the reinforcing and therapeutic effects of drugs even in subjects who have no prior experience with the drug.

Adult↗

Methylphenidate and cocaine have a similar in vivo potency to block dopamine transporters in the human brain.

The reinforcing effects of cocaine and methylphenidate have been linked to their ability to block dopamine transporters (DAT). Though cocaine and methylphenidate have similar in vitro affinities for DAT the abuse of methylphenidate in humans is substantially lower than of cocaine. To test if differences in in vivo potency at the DAT between these two drugs could account for the differences in their abuse liability we compared the levels of DAT occupancies that we had previously reported separately for intravenous methylphenidate in controls and for intravenous cocaine in cocaine abusers. DAT occupancies were measured with Positron Emission Tomography using [11C]cocaine, as a DAT ligand, in 8 normal controls for the methylphenidate study and in 17 active cocaine abusers for the cocaine study. The ratio of the distribution volume of [11C]cocaine in striatum to that in cerebellum, which corresponds to Bmax/Kd +1, was used as measure of DAT availability. Parallel measures were obtained to assess the cardiovascular effects of these two drugs. Methylphenidate and cocaine produced comparable dose-dependent blockade of DAT with an estimated ED50 (dose required to block 50% of the DAT) for methylphenidate of 0.07 mg/kg and for cocaine of 0.13 mg/kg. Both drugs induced similar increases in heart rate and blood pressure but the duration of the effects were significantly longer for methylphenidate than for cocaine. The similar in vivo potencies at the DAT for methylphenidate than for cocaine are in agreement with their reported relative in vitro affinities (Ki 390 nM and 640 nM respectively), which is likely to reflect the similar degree of uptake (8-10% of the injected dose) and regional distribution of these two drugs in the human brain. Thus, differences in the in vivo potency of these two drugs at the DAT cannot be responsible for the differences in their rate of abuse in humans. Other variables i.e. longer duration of methylphenidate's side effects may counterbalance its reinforcing effects.

Adult↗

Reinforcing, subject-rated, and physiological effects of intranasal methylphenidate in humans: a dose-response analysis.

The results of previously published reports suggest that oral methylphenidate has potential for abuse. An increase in insufflation of methylphenidate has been reported recently. To our knowledge, however, there are no published reports that examined the effects of intranasal methylphenidate. The purpose of this experiment was to characterize the reinforcing, subject-rated, and physiological effects of intranasal methylphenidate (0, 10, 20, and 30 mg). Eight volunteers (five males and three females) with recent histories of recreational stimulant use were recruited to participate in this experiment. Drug doses were administered in a double-blind fashion under medical supervision, but for safety purposes they were administered in ascending order. Intranasal methylphenidate increased the crossover point on the Multiple-Choice Questionnaire in a linear fashion, which suggests that intranasal methylphenidate functioned as a reinforcer. Intranasal methylphenidate also produced linear dose-dependent prototypical stimulant-like subjective effects (e.g. increases in ratings of Good Effects and High). Intranasal methylphenidate increased heart rate as a function of dose, but the magnitude of this effect was not clinically significant (i.e. average peak heart rate following administration of the highest dose was less than 82 beats per min). The results of this study suggest that across a range of doses, intranasal methylphenidate produces behavioral effects that are characteristic of abused stimulants. Future studies should test higher doses and directly compare the behavioral effects of intranasal methylphenidate to those of a prototypical abused stimulant (e.g. cocaine).

Administration, Intranasal↗

Symptomatic improvement in children with ADHD treated with long-term methylphenidate and multimodal psychosocial treatment.

OBJECTIVE: To test the hypotheses that in children with attention-deficit/hyperactivity disorder (ADHD) (1) symptoms of ADHD, oppositional defiant disorder, and overall functioning are significantly improved by methylphenidate combined with intensive multimodal psychosocial treatment compared with methylphenidate alone and with methylphenidate plus attention control and (2) more children receiving combined treatment can be taken off methylphenidate. METHOD: One hundred three children with ADHD (ages 7-9), free of conduct and learning disorders, who responded to short-term methylphenidate were randomized for 2 years to (1) methylphenidate alone; (2) methylphenidate plus psychosocial treatment that included parent training and counseling, social skills training, psychotherapy, and academic assistance, or (3) methylphenidate plus attention psychosocial control treatment. Assessments included parent, teacher, and psychiatrist ratings, and observations in academic and gym classes. RESULTS: Combination treatment did not lead to superior functioning and did not facilitate methylphenidate discontinuation. Significant improvement occurred across all treatments and continued over 2 years. CONCLUSIONS: In stimulant-responsive children with ADHD, there is no support for adding ambitious long-term psychosocial intervention to improve ADHD and oppositional defiant disorder symptoms. Significant benefits from methylphenidate were stable over 2 years.

Attention Deficit Disorder with Hyperactivity↗

Social functioning in children with ADHD treated with long-term methylphenidate and multimodal psychosocial treatment.

OBJECTIVE: To test that methylphenidate combined with intensive multimodal psychosocial intervention, which includes social skills training, significantly enhances social functioning in children with attention-deficit/hyperactivity disorder (ADHD) compared with methylphenidate alone and methylphenidate plus nonspecific psychosocial treatment (attention control). METHOD: One hundred three children with ADHD (ages 7-9), free of conduct and learning disorders, who responded to short-term methylphenidate were randomized for 2 years to receive (1) methylphenidate alone, (2) methylphenidate plus multimodal psychosocial treatment that included social skills training, or (3) methylphenidate plus attention control treatment. Assessments included parent, child, and teacher ratings of social function and direct school observations in gym. RESULTS: No advantage was found on any measure of social functioning for the combination treatment over methylphenidate alone or methylphenidate plus attention control. Significant improvement occurred across all treatments and continued over 2 years. CONCLUSIONS: In young children with ADHD, there is no support for clinic-based social skills training as part of a long-term psychosocial intervention to improve social behavior. Significant benefits from methylphenidate were stable over 2 years.

Attention Deficit Disorder with Hyperactivity↗

Evidence that methylphenidate enhances the saliency of a mathematical task by increasing dopamine in the human brain.

OBJECTIVE: Methylphenidate is the most commonly prescribed drug for attention deficit hyperactivity disorder (ADHD), yet its therapeutic mechanisms are poorly understood. The objective of this study was to assess if methylphenidate, by increasing dopamine (neurotransmitter involved in motivation) in brain, would enhance the saliency of an academic task, making it more interesting. METHOD: Healthy subjects (N=16) underwent positron emission tomography with [(11)C]raclopride (dopamine D(2) receptor radioligand that competes with endogenous dopamine for binding) to assess the effects of oral methylphenidate (20 mg) on extracellular dopamine in the striatum. The authors compared the effects of methylphenidate during an academic task (solving mathematical problems with monetary reinforcement) and a neutral task (passively viewing cards with no remuneration). In parallel, the effects of methylphenidate on the interest that the academic task elicited were also evaluated. RESULTS: Methylphenidate, when coupled with the mathematical task, significantly increased extracellular dopamine, but this did not occur when coupled with the neutral task. The mathematical task did not increase dopamine when coupled with placebo. Subjective reports about interest and motivation in the mathematical task were greater with methylphenidate than with placebo and were associated with dopamine increases. CONCLUSIONS: The significant association between methylphenidate-induced dopamine increases and the interest and motivation for the task confirms the prediction that methylphenidate enhances the saliency of an event by increasing dopamine. The enhanced interest for the task could increase attention and improve performance and could be one of the mechanisms underlying methylphenidate's therapeutic effects. These findings support educational strategies that make schoolwork more interesting as nonpharmacological interventions to treat ADHD.

Adult↗