Influence Of Methylphenidate Research Articles

The influence of methylphenidate on auditory brainstem response patients with attention deficit hyperactivity disorder; an exploratory study.

Attention-deficit hyperactivity disorder (ADHD), characterized by periods of inattention, overactivity, and impulsiveness, is the most prevalent neurodevelopmental disorder among children. Auditory Brainstem Response (ABR) is a technique in which clickshaped sounds elicit potentials that are recorded from electrodes placed on a patient's skull. Extant research indicates that ABR is frequently affected in neurodevelopmental disorders such as ADHD. Methylphenidate (MPH), a psychostimulant, is often prescribed to children with ADHD as a first-line pharmacological treatment. The aim of this study was to explore the effects of Methylphenidate treatment on previously observed amplitude alterations in the ABR of patients with ADHD. We recruited 32 drug-naïve children and adolescents (19 males and 13 females; mean age 11 years) diagnosed with ADHD and 35 health controls (15 males and 20 females; mean age 12 years). The ADHD group was treated with Methylphenidate, and ABR was recorded before treatment and at a steady state of medical treatment. Medicated ADHD patients exhibited increased activity in the right side ABR in Wave VI. A significant increase in activity was found in a part of the ABR thought to correspond to the thalamic area in medicated ADHD patients compared to the same area of non-medicated ADHD patients. The results add to the growing body of research suggesting that specific ABR peaks correlate to certain psychiatric symptoms.

ПЕРСПЕКТИВНЫЕ НАПРАВЛЕНИЯ ПРИМЕНЕНИЯ ПРОИЗВОДНЫХ ПИПЕРИДИНА В КАЧЕСТВЕ СТРУКТУРНЫХ КОМПОНЕНТОВ НЕЙРОТРОПНЫХ ЛЕКАРСТВЕННЫХ СРЕДСТВ

Piperidine is one of the most common heterocycles, and its derivatives are found in many pharmacological groups, including neurotropic drugs. These compounds are numerous among analgesics, and, in addition to “classical” promedol, fentanyl and its derivatives, the paper presents the results of studying new compounds with analgesic activity and piperidine cycle. Reviews of such piperidine antipsychotics as haloperidol and risperidone have been considered, and new compounds showing antipsychotic activity through their effects on dopamine and serotonin receptors have been elucidated. The data on the influence of methylphenidate on the brain in case of attention deficit/ hyperactivity disorder (ADHD) have been analyzed, which help to understand the disturbances occurring in this disease. Tiagabine has been considered as an antiepileptic agent reducing the number of seizures in resistant forms of partial epilepsy, as well as the activation of microglia and may be effective in neurodegenerative diseases. The last section is devoted to drugs for the treatment of Alzheimer’s disease (AD), namely donepezil, its modifications, and some new compounds potentially capable of inhibiting AD progression through the inhibition of Aβ42 protein synthesis.

Methylphenidate and the risk of burn injury among children with attention-deficit/hyperactivity disorder.

Attention-deficit/hyperactivity disorder (ADHD) is associated with a higher risk of burn injury than in the normal population. Nevertheless, the influence of methylphenidate (MPH) on the risk of burn injury remains unclear. This retrospective cohort study analysed the effect of MPH on the risk of burn injury in children with ADHD. Data were from Taiwan's National Health Insurance Research Database (NHIRD). The sample comprised individuals younger than 18 years with a diagnosis of ADHD (n = 90 634) in Taiwan's NHIRD between January 1996 and December 2013. We examined the cumulative effect of MPH on burn injury risk using Cox proportional hazards models. We conducted a sensitivity analysis for immortal time bias using a time-dependent Cox model and within-patient comparisons using the self-controlled case series model. Children with ADHD taking MPH had a reduced risk of burn injury, with a cumulative duration of treatment dose-related effect, compared with those not taking MPH. Compared with children with ADHD not taking MPH, the adjusted hazard ratio for burn injury was 0.70 in children taking MPH for <90 days (95% confidence interval (CI) 0.64-0.77) and 0.43 in children taking MPH for ≥90 days (95% CI 0.40-0.47), with a 50.8% preventable fraction. The negative association of MPH was replicated in age-stratified analysis using time-dependent Cox regression and self-controlled case series models. This study showed that MPH treatment was associated with a lower risk of burn injury in a cumulative duration of treatment dose-related effect manner.

Influence of Methylphenidate on Long-Term Neuropsychological and Everyday Executive Functioning After Traumatic Brain Injury in Children with Secondary Attention Problems.

To investigate the effects of methylphenidate on long-term executive and neuropsychological functioning in children with attention problems following TBI, as well as the relationship between methylphenidate associated changes in lab-based neuropsychological measures of attentional control, processing speed, and executive functioning and parent- or self-report measures of everyday executive functioning. 26 children aged 6-17 years, who were hospitalized for moderate-to-severe blunt head trauma 6 or more months previously, were recruited from a large children's hospital medical center. Participants were randomized into a double-masked, placebo-controlled cross-over clinical trial. Participants completed a comprehensive neuropsychological battery and parent- and self-report ratings of everyday executive functioning at baseline, and at 4 weeks and 8 weeks following upward titration of medication to an optimal dose or while administered a placebo. Methylphenidate was associated with significant improvements in processing speed, sustained attention, and both lab-based and everyday executive functioning. Significant treatment-by-period interactions were found on a task of sustained attention. Participants who were randomized to the methylphenidate condition for the first treatment period demonstrated random or erratic responding, with slower and more variable response times when given placebo during the second period. Results indicate that methylphenidate treatment is associated with positive outcomes in processing speed, sustained attention, and both lab-based and everyday measures of executive functioning compared to placebo group. Additionally, results suggest sustained attention worsens when discontinuing medication. (JINS, 2019, 25, 740-749).

Effects of dual tasking and methylphenidate on gait in children with attention deficit hyperactivity disorder

Effects of dual tasking on motor processes such as gait have been mainly investigated with healthy adults and clinical older samples whereas studies with clinical samples of children with attention deficit hyperactivity disorder (ADHD) are rare. Similarly, even though methylphenidate (MPH) is the most often prescribed medication for children with ADHD, the influence of MPH on children’s gait under single-task and dual-task situations remains poorly understood. In the current study, children diagnosed with ADHD (n = 26) came twice to the laboratory, once without and once with MPH medication. They were asked to walk over an electronic walkway without a concurrent task (motor single task) and while solving different cognitive tasks (motor-cognitive dual task). Gait variability and cognitive performance were measured. Children’s performance was compared to an age- and sex-matched control sample of typically developing children (n = 26) who were also tested twice. Results indicated considerable effects of dual tasking on children’s gait irrespective of group (ADHD vs. controls), with children diagnosed with ADHD showing more pronounced gait alterations in dual-task situations as compared to controls. Furthermore, MPH medication in children with ADHD enabled them to substantially decrease their stride time variability to a level that was comparable to the level of typically developing children. Overall, our findings support the notion that higher cognitive processes such as attention and executive functions influence gait and that MPH can positively affect cognitive and motor processes such as gait.

Extinction memory is facilitated by methylphenidate and regulated by dopamine and noradrenaline receptors

Extinction is defined as the learned inhibition of retrieval and is the mainstay of exposure therapy, which is widely used to treat drug addiction, phobias and fear disorders. The psychostimulant, methylphenidate (MPH) is known to increase extracellular levels of noradrenaline and dopamine by blocking their reuptake and studies have demonstrated that MPH can modulate hippocampal physiology and/or functions including long-term potentiation (LTP), learning and memory. However, the influence of MPH on fear extinction memory has been insufficiently studied. Here we investigate the effect of MPH infused into the CA1 region of the hippocampus on extinction memory in animals normally incapable of showing contextual fear conditioning (CFC) extinction because of weak training, and the possible mechanisms through which it acts during this process. For this, male Wistar rats with infusion cannulae stereotaxically implanted in the CA1 region were submitted to a weak extinction protocol in a CFC apparatus. Animals that received intra-CA1 infusion of MPH (12.5μg/side) 20min before the extinction training (Ext Tr) expressed less freezing behavior than Veh-treated animals during both Ext Tr and extinction retention Test (Ext Test). Additionally, the administration of MPH+Timolol (1μg/side) or MPH+SCH23390 (1.5μg/side) intra-CA1 20min before the Ext Tr blocked the enhancing effect of the MPH on extinction learning. These results suggest that MPH in the CA1 region of the hippocampus is able to induce the consolidation of extinction memory and this process occurs through both β-adrenergic and D1/D5 dopaminergic receptors.

Efeitos do Metilfenidato no Desempenho Motor de Crianças com TDAH

O presente estudo teve como objetivo analisar a influência do Metilfenidato no desempenho motor de crianças com Transtorno de Déficit de Atenção e Hiperatividade. Foram selecionadas 21 crianças, de 7 a 10 anos, provenientes de três escolas municipais de Maringá (PR), de ambos os gêneros, com diagnóstico clínico confirmado de TDAH, sendo as mesmas submetidas a duas avaliações do desenvolvimento motor, utilizando o instrumento “Movement Assessment Battery for Children”, em dois momentos distintos, com e sem a utilização do Metilfenidato. Os respectivos testes motores foram realizados no próprio ambiente escolar e os resultados foram bastante diversificados, sendo que na destreza manual os escores não sofreram modificação com e sem utilização do medicamento, nas habilidades de lançar e receber houve uma diminuição na pontuação do teste com o uso do fármaco, enquanto em relação ao equilíbrio observou-se o inverso. Dessa forma, mediante a pequena amostra investigada, mais pesquisas são necessárias visando explorar os efeitos dose-resposta da correspondente medicação em diferentes atividades físicas ou contextos.

The Influence of Methylphenidate on Hyperactivity and Attention Deficits in Children With ADHD: A Virtual Classroom Test

Objective: This study compares the performance in a continuous performance test within a virtual reality classroom (CPT-VRC) between medicated children with ADHD, unmedicated children with ADHD, and healthy children. Method: N = 94 children with ADHD (n = 26 of them received methylphenidate and n = 68 were unmedicated) and n = 34 healthy children performed the CPT-VRC. Omission errors, reaction time/variability, commission errors, and body movements were assessed. Furthermore, ADHD questionnaires were administered and compared with the CPT-VRC measures. Results: The unmedicated ADHD group exhibited more omission errors and showed slower reaction times than the healthy group. Reaction time variability was higher in the unmedicated ADHD group compared with both the healthy and the medicated ADHD group. Omission errors and reaction time variability were associated with inattentiveness ratings of experimenters. Head movements were correlated with hyperactivity ratings of parents and experimenters. Conclusion: Virtual reality is a promising technology to assess ADHD symptoms in an ecologically valid environment.

Influence of Methylphenidate on the Frequency of Stuttering: A Randomized Controlled Trial.

Recently, a case report described a decrease in frequency of stuttering after intake of methylphenidate (MPH). This study was undertaken to investigate if this effect could again be reproduced in a population of young healthy male adult persons with developmental stuttering. A double-blind randomized crossover trial, with a 2-week washout period, including 15 Dutch-speaking young healthy persons with developmental stuttering, assessed the effects of a single dose of 20 mg MPH compared with placebo on stuttering. Dependent and 1-sample t tests were used to detect significant differences. The end point was the number of stutter moments and self-perceived improvement. MPH yielded a significant decrease in the number of stutter moments when reading and speaking (P = 0.002), which was not the case with placebo (P = 0.090). There was a significant improvement from baseline after intake of MPH as compared with placebo (P = 0.003). Self-perceived improvement with MPH was not significantly better as compared with placebo (P = 0.28). This study showed that the participants had an objective statistically significant decrease in the frequency of stuttering with MPH, and this was not the case with placebo. This was also the case for a reduction in stutter moments when reading out loud and speaking spontaneously. However, this result was not subjectively perceived by the participants.

Effects of methylphenidate on the behavior of male 5xFAD mice

Alzheimer's disease is a neurodegenerative disorder characterized by a loss of memory and spatial orientation. It is also reported that the dopamine system is affected. Dopamine plays a prominent role in motor functions, motivation, emotion, arousal and reward, and it is important for learning and memory. One model that represents characteristic hallmarks of Alzheimer's disease is the 5xFAD mouse model, in which parenchymal plaque load starts at 2months of age. Transgenic 5xFAD mice show the first behavioral deficits at 6months, which are evident at 9months of age. In this study, we investigated the pharmacological influence of methylphenidate (MPH) on behavioral deficits of 5xFAD mice. Using a battery of behavioral tests, we observed no influence of MPH on anxiety in the elevated plus maze, whereas the locomotion and explorative activity in the open field was increased in transgenic and non-transgenic 5xFAD mice after the application of MPH. Further MPH inhibits habituation in the open field in healthy 5xFAD littermates after the application of 10mg/kg MPH. On the other hand, 10mg/kg MPH improved spatial memory in 6-month-old transgenic 5xFAD males, i.e., at a time point when deficits start to occur. However, in 9-month-old transgenic mice, MPH did not improve persisting learning and memory deficits. We concluded that MPH might improve the non-cognitive, apathy-like behavior (indicated by a reduced exploration), but it has no influence on sustained Alzheimer typical learning and memory deficits.

Influence of methylphenidate on spatial attention asymmetry in adolescents with attention deficit hyperactivity disorder (ADHD): preliminary findings

Atypical asymmetries of spatial attention have been reported in children with attention deficit hyperactivity disorder (ADHD) and may be exacerbated by non-spatial factors such as attentional capacity. Although preliminary evidence suggests that asymmetries of attention in ADHD may be modifiable by the psychostimulant, methylphenidate, further placebo-controlled studies are required. This study first aimed to confirm recent evidence that increasing non-spatial processing load at fixation can unmask a spatial gradient of target detection in children with ADHD but not Controls. Second, we used placebo-controlled randomised trial methodology to ask whether 20mg of methylphenidate (MPH) could remediate any load-dependent asymmetry of spatial attention in adolescents with ADHD. Twelve male adolescents with ADHD were assessed twice in a double-blind, randomized design, under either placebo or an acute dose of methylphenidate. Thirteen typically developing adolescent Controls completed a single session under placebo. Participants completed a computer-based task in which they monitored a centrally presented rapid serial visual presentation stream for a probe stimulus, while also responding to brief peripheral events. The attentional load of the central task was manipulated by varying the target instructions but not the physical stimuli or the frequency of targets. Between-group analyses under placebo conditions indicated that increased attentional load induced a spatial gradient for target detection in the ADHD but not Controls, such that load slowed response times for left, but not, right hemi-field targets. This load-dependent spatial asymmetry in the adolescents with ADHD was abolished by administration of methylphenidate. Methylphenidate may “normalise” target detection between the hemi-fields in ADHD via enhancement of the right-lateralised ventral attention networks that support non-spatial attention.

Influence of methylphenidate on circadian rhythmicity and sleep in adult attention-deficit/hyperactivity disorder

To explore the effect of methylphenidate on sleep and circadian rhythmicity, actigraphic sleep-wake rhythm, Dim Light Melatonin Onset (DLMO), Phase Angle Difference (PAD; time between DLMO and mid-sleep) and attention-deficit/hyperactivity disorder (ADHD) Rating Scale were assessed before and after 4-week treatment with methylphenidate in 10 adults with ADHD. During methylphenidate treatment DLMO did not change, while melatonin concentration at 23.00 hours increased. Phase advance type (PAD > 6 h) before treatment was associated with a greater treatment-related reduction in attention symptoms. These results suggest that PAD > 6 h might have a predictive value for the effect of methylphenidate.

Autonomic hypoactivity in boys with attention-deficit/hyperactivity disorder and the influence of methylphenidate

Objectives. This study investigates an overall autonomic hypoactivity reflecting hypoarousal as important aetiological factor in ADHD at baseline during rest and in response towards stimuli. In addition, effects of methylphenidate (MPH) are examined. We further assessed whether this hypoarousal is a stable characteristic or ameliorated by arousing emotional stimuli. Methods. Boys with ADHD were examined with (n = 35) or without MPH (n = 45) and compared with healthy boys (n = 22) regarding skin conductance level (SCL) during rest and skin conductance responses (SCRs) as well as valence and arousal ratings in response to positive, neutral, and negative pictures. Results. ADHD children without MPH were characterized by reduced baseline SCL and overall reduced SCRs. ADHD children with MPH never differed from control children. All groups displayed normal valence and arousal ratings of the stimuli and enhanced SCRs to emotional in comparison to neutral pictures. Conclusions. This is the first study to unravel (1) a general autonomic hypoactivity in ADHD children at baseline and in response to low arousing neutral and highly arousing emotional stimuli, and (2) hints that MPH normalizes this hypoactivity. Results contribute to the understanding of ADHD aetiology and MPH functionality, and are consistent with the cognitive-energetic model of ADHD.

Methylphenidate remediates error-preceding activation of the default mode brain regions in cocaine-addicted individuals

Many previous studies suggest the potential of psychostimulants in improving cognitive functioning. Our earlier pharmacological brain imaging study showed that intravenous methylphenidate (MPH) improves inhibitory control by altering cortico–striato–thalamic activations in cocaine-dependent (CD) individuals. Here we provide additional evidence for the effects of MPH in restoring cerebral activations during cognitive performance. Ten CD individuals performed a stop signal task (SST) during functional magnetic resonance imaging (fMRI) in two sessions, in which either MPH (0.5mg/kg body weight) or saline was administered intravenously. In the SST, a frequent go signal instructs participants to make a speeded response and a less frequent stop signal instructs them to withhold the response. Our previous work described increased activation of the precuneus/posterior cingulate cortex and ventromedial prefrontal cortex—regions of the default mode network (DMN)—before participants committed a stop error in healthy control but not CD individuals (Bednarski et al., 2011). The current results showed that, compared to saline, MPH restored error-preceding activations of DMN regions in CD individuals. The extent of the changes in precuneus activity was correlated with MPH-elicited increase in systolic blood pressure. These findings suggest that the influence of MPH on cerebral activations may extend beyond cognitive control and provide additional evidence warranting future studies to investigate the neural mechanisms and physiological markers of the efficacy of agonist therapy in cocaine dependence.

Prepulse Inhibition of Acoustic Startle and the Influence of Methylphenidate in Children With ADHD

Objective: ADHD is common among children with comorbidity of enuresis. Findings concerning prepulse inhibition (PPI) of startle reflexes are controversial. Although PPI is improved through desamino-arginine vasopressin (dDAVP) in enuresis, some patients also improve concomitant ADHD through dDAVP. This study aims to evaluate whether methylphenidate (MPH) also improves PPI in ADHD. Method: Nineteen ADHD patients were investigated in a prospective, double-blind, crossover study with MPH versus placebo. PPI was measured as a reduction of acoustic startle reflexes. Subgroups of gender, ADHD subtype, and baseline PPI were analyzed. Results: Median baseline PPI of ADHD patients (51.7%) was below the value of age-matched normal controls (73%, p = .090). MPH showed no improvement in the whole group, or the subgroups gender or subtype. Reduced baseline PPI was significantly improved (22.5%-39.3%, p = .039). Conclusion: Heterogeneity of ADHD is confirmed with a wide range of baseline PPI. The improvement of reduced baseline PPI through MPH suggests impaired sensorimotor gating in this subgroup.

Methylphenidate (MPH) promotes visual cortical activation in healthy adults in a cued visuomotor task

Seeking for the mechanisms by which methylphenidate (MPH) improves behavior has demonstrated that MPH modulates excitability in the primary motor cortex. However, little is known about the influence of MPH on top-down controlled mechanisms in the sensory domain. The present study explored the effects of MPH on the activation of visual cortices in healthy adults who performed a cued visuo-motor task in a double-blind placebo-controlled crossover design. Two distinct measures, posterior alpha power and occipital slow cortical potentials (SCPs), were used to reflect raise in excitability and attention-based activation of visual cortical areas. According to the results, performance parameters (reaction time, response variance and error rate) were not affected by MPH. At the neurophysiologic level reflected by reduced alpha power, MPH increased the overall excitability of the occipital cortex, but not the parietal cortex. Before the cued response, MPH reduced alpha power and increased SCPs only before right hand responses, mostly at the right occipital location. It can be concluded that in visuo-motor tasks, MPH has the potency of adjusting the background excitation/inhibition balance of visual areas. Additionally, MPH may raise the attention controlled activation of visual cortical regions, especially during increased response control.

Effects of Methylphenidate on performance of a practical pistol shooting task: a quantitative electroencephalography (qEEG) study.

BackgroundThe present study examined absolute alpha power using quantitative electroencephalogram (qEEG) in bilateral temporal and parietal cortices in novice soldiers under the influence of methylphenidate (MPH) during the preparatory aiming period in a practical pistol-shooting task. We anticipated higher bi-hemispheric cortical activation in the preparatory period relative to pre-shot baseline in the methylphenidate group when compared with the control group because methylphenidate has been shown to enhance task-related cognitive functions.MethodsTwenty healthy, novice soldiers were equally distributed in control (CG; n = 10) and MPH groups 10 mg (MG; n = 10) using a randomized, double blind design. Subjects performed a pistol-shooting task while electroencephalographic activity was acquired.ResultsWe found main effects for group and practice blocks on behavioral measures, and interactions between group and phases on electroencephalographic measures for the electrodes T3, T4, P3 and P4. Regarding the behavioral measures, the MPH group demonstrated significantly poorer in shooting performance when compared with the control and, in addition, significant increases in the scores over practice blocks were found on both groups. In addition, regarding the electroencephalographic data, we observed a significant increase in alpha power over practice blocks, but alpha power was significantly lower for the MPH group when compared with the placebo group. Moreover, we observed a significant decrease in alpha power in electrodes T4 and P4 during PTM.ConclusionAlthough we found no correlation between behavioral and EEG data, our findings show that MPH did not prevent the learning of the task in healthy subjects. However, during the practice blocks (PBs) it also did not favor the performance when compared with control group performance. It seems that the CNS effects of MPH demanded an initial readjustment period of integrated operations relative to the sensorimotor system. In other words, MPH seems to provoke a period of initial instability due to a possible modulation in neural activity, which can be explained by lower levels of alpha power (i.e., higher cortical activity). However, after the end of the PB1 a new stabilization was established in neural circuits, due to repetition of the task, resulting higher cortical activity during the task. In conclusion, MPH group performance was not initially superior to that of the control group, but eventually exceeded it, albeit without achieving statistical significance.

A preliminary study on the effect of methylphenidate on motor performance in children with comorbid DCD and ADHD

Attention Deficit Hyperactive Disorder (ADHD) and Developmental Coordination Disorder (DCD) are two developmental disorders with considerable comorbidity. The impact of Methylphenidate (MPH) on ADHD symptoms is well documented. However, the effects of MPH on motor coordination are less studied. We assessed the influence of MPH on motor performance of children with comorbid DCD and ADHD. Participants were 18 children (13 boys, mean age 8.3 years) diagnosed with comorbid DCD and ADHD. A structured clinical interview (K-SADS-PL) was used to determine psychopathology and the Movement Assessment Battery for Children–Checklist were used to determine criterion for motor deficits. The Movement Assessment Battery for Children (M-ABC) was administrated to all participants once under the influence of MPH and once under a placebo pill condition. The motor tests were administered on two separate days in a double-blinded design. Participants’ motor performance with MPH was significantly superior to their performance in the placebo condition. Significant improvement was observed in all the M-ABC sub-tasks except for static balance performance. The findings suggest that MPH improves motor coordination in children with comorbid DCD and ADHD but clinically significant improvement was found in only 33% of the children.

Violence under the influence of methylphenidate as determined by hair analysis

A 26-year-old woman under the influence of alcohol assaulted another person at a party in late November 2008. Afterward, she claimed that her drink was spiked with Ritalin, which would account for her bizarre behavior. Neither urine nor blood was sampled, because of the elapsed time after the incident. Hair was collected in late February 2009 and sent to our laboratory for methylphenidate testing. The hair strand was decontaminated twice using methylene chloride and then segmented. Each segment was cut into small pieces and about 30 mg was incubated in an ultrasonic bath for 3 h in buffer solution at pH 5.5 in the presence of 100 ng of 3,4-methylenedioxymethamphetamine (MDMA)-d5 used as internal standard (IS). Each mixture was neutralized with NaOH and extracted with hexane/ethyl acetate (90:10). After evaporation, the residue was reconstituted in 200 μl of acetonitrile/formate buffer (5:95). Each sample was subjected to liquid chromatography-tandem mass spectrometry (LC-MS-MS) with a gradient elution of acetonitrile and formate buffer. For both methylphenidate and MDMA-d5, detection was performed with two product ions each (m/z 234 to 84 and 56 for methylphenidate; m/z 199 to 135 and 165 for IS). The method showed a linear response from 0.5 to 500 pg/mg with a limit of quantitation of 0.5 pg/mg. Hair collection was made 3 months after the incident, so it was decided that the hair be analyzed in three 4-cm segments. Methylphenidate was detected only in the proximal segment at 1.0 pg/mg, while the result was negative in the other two segments. These results support the suggestion of a single exposure to methylphenidate in the previous 4 months, which includes the time of the party.

The Effect of Methylphenidate and Placebo on Eye–Hand Coordination Functioning and Handwriting of Children with Attention Deficit Hyperactivity Disorder

Israeli children who were diagnosed as having attention deficit hyperactivity disorder participated in the study. The children were assessed three times in a specially constructed battery of tests. The battery of tests included variables assessing eye–hand coordination skills, writing, and behavioral assessment of the teacher. The design was in the format of a double blind, randomized, crossover, placebo-control procedure. The results showed that methylphenidate (MPH) improved some cognitive functions of eye–hand coordination slightly better than placebo. In addition, behavior variables assessed by the teachers improved only under the influence of MPH.