• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.23 no.2
• /
• pp.49-56
• /
• 2012

Methylphenidate is a widely used stimulant for treatment of attention-deficit hyperactivity disorder (ADHD). In addition to core symptoms of attention and behavioral symptoms, methylphenidate is even effective for executive functions. However, abuse and misuse of stimulants, including methylphenidate, for the purpose of cognitive enhancement is an issue of concern worldwide. Some prejudices and misunderstandings against methylphenidate are popular ; however, little attention has been given to the neuropsychiatric evidence of methylphenidate for enhancement of cognitive function among healthy populations. In this article, our aim was to conduct a review of previous studies investigating the effect of methylphenidate in healthy populations. Findings from several recent studies have demonstrated the effectiveness of methylphenidate for enhancement of cognitive function in healthy populations. The mechanisms of cognitive enhancement are thought to be associated with motivation and the reward circuit in the brain. However, when considering the risk to benefit, an official discussion of the use of methylphenidate among healthy members of the population would be premature. Instead, investigation of epidemiological studies of the prevalence of misuse of stimulants among healthy members of the population, particularly adolescents and college students, is needed. In addition, based on achievements reported in previous studies, investigation of the effect of an approach using non-pharmacological enhancing motivation, which will in turn result in increased cognitive function would be helpful.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.25 no.2
• /
• pp.82-88
• /
• 2014

Objectives : The aim of our study was to investigate association of norepinephrine transporter gene (SLC6A2) polymorphism and side effects of osmotic-release oral system methylphenidate (OROS MPH) in children with attention-deficit hyperactivity disorder (ADHD). Methods : We recruited drug naive children with ADHD (N=97). We administered OROS MPH by tolerable dosage. At week 8 of treatment, parents completed the Barkley's side effect rating scale. We analyzed two SLC6A2 single nucleotide polymorphisms (SNPs), rs192303 and rs3785143, with blood of subjects. We compared the frequency and severity of each side effect among SLC6A2 genotypes of 2 SNPs. Results : In the analysis of frequency of each side effect, irritability differed according to rs192303 and rs3785143 genotype. In comparisons of severity, talking less and disinterest differed according to rs192303 genotype. In the case of rs3785143, severities of disinterest and irritability were involved with genotype. Conclusion : Side effects of OROS MPH showed an association with SLC6A2 genotype.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.23 no.3
• /
• pp.154-160
• /
• 2012

Objectives : The purpose of this study was to investigate clinical characteristics of children and adolescents with autism spectrum disorders (ASDs) using methylphenidate (MPH). Methods : Retrospective review of the charts of 79 children and adolescents with ASDs, who visited the Department of Child and Adolescent Psychiatry of Seoul National Hospital, from July 2010 to July 2011, was conducted. Changes in illness severity and improvement were measured using the Clinical Global Impression-Severity of illness (CGI-S) and Clinical Global Impression-Improvement (CGI-I) Scales. Results : We found that MPH was prescribed in 23 (29.1%) children and adolescents. Of the 23 patients on MPH, 4 patients (17.4%) were on MPH monotherapy and 18 patients (78.3%) were using risperidone concomitantly. MPH was prescribed primarily for symptoms of hyperactivity and impulsivity in ASDs patients. The mean dosage of MPH was $26.2{\pm}11.1$mg/day and mean duration of treatment was $31.9{\pm}28.7$ months. Mean CGI-S score improved significantly from baseline to endpoint (from $5.4{\pm}0.6$ to $4.1{\pm}0.9$ ; p<.01). MPH was reported to be effective in 17 patients (17/23, 73.9%), and 10 patients (10/23, 43.5%) reported side effects. Side effects included decreased appetite (4/23, 17.4%), tic (2/23, 8.6%), sleep disturbances (2/23, 8.6%), headache (1/23, 4.3%) and irritability (1/23, 4.3%). Conclusion : The results of this study demonstrate that MPH may be used effectively and safely in children and adolescents with ASDs with hyperactivity and impulsivity. Future controlled trials are needed to confirm these findings.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.1 no.1
• /
• pp.77-88
• /
• 1990

Management of the child with Attention-Deficit Hyperativity Disorder(ADHD) reguires a comprehensive approach of cognitive-behavioral, educational, and pharmacological interventions. Establishing the valid diagnosis is the first step of management. After the diagnosis is made, the clinician must then interpret the diagnosis and its impliations to the child, parents, and teachers. The pharmacotherapy is most effeceive, and the CNS stimulants (methylphenidate) is drug of choice. Although generally not as effective as stimulants, triacyclic antidepressants, clonidine, antipsychotics offer the alternatives to stimulants therapy. Additional treatments, including psychotherapy, cogntive-behavioral approach, educational infervention, parental counseling are also essential in managing the child with ADHD. Finally, controversial approaches-diet therapy, mineral therapy, hypoglycemia, megavitamin therapy, refined sugars, neurophysiological retraining approaches are reviewed.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.24 no.3
• /
• pp.157-163
• /
• 2013

Objectives : Previous studies reported that attention-deficit hyperactivity disorder (ADHD) resulted from a deficit of selective attention and sustained attention. In this study, we assessed the result of methylphenidate-induced changes of the cerebral frontal executive functions in patients with ADHD. Methods : The subjects in this study consisted of 16 ADHD patients whose age ranged from 7 to 12. We used ADHD Diagnostic System (ADS) for the attention improvement, and the Stroop Test for the executive function response to pharmacotherapy with MPH. Results : After pharmacotherapy with methylphenidate for 12 weeks, the study group showed improvement in the clinical aspects through Clinical Global Impression-Severity, ADHD-rating scale and Inattention/Overactivity With Aggression Conner's Parents Rating Scale. In the ADS test, only in auditory task there was a decrease of both the response time and the standard deviation of the response time significantly. In the Stroop Test, there was a decrease in the word task, color task and color-word task significantly. Conclusion : Our results show that psychostimulant medication improves neuropsychological function, including the cerebral frontal executive function. This study implies that we have to consider the improvement of executive function, as well as attention when evaluating the efficacy of treatment.

• Korean Journal of Biological Psychiatry
• /
• v.21 no.2
• /
• pp.37-48
• /
• 2014

Besides from medical data, the patients who were previously called as attention disorder, mental instability, moral imbeciles, or moral defectives, can also be identified by exploring literatures and historical figures. In the past, as we can notice from the titles, they were recognized as a 'moral defect group'. And rather than treating them, separation from the society was the main solution. After the endemic encephalitis from 1917 to late 1920s, however, many survivors suffered from behavioral problems similar to those of the previous 'moral defect group' and studies on the relationship between brain damage and behavior problems were started henceforth. After being known as the 'minimal brain dysfunction', it was developed into the current attention-deficit/hyperactivity disorder. While the disease concept changed and developed over time, after numerous trials and errors, treatment medication starting from central nervous system stimulants such as amphetamine and methylphenidate is used for treatment in children and adult patients with ADHD, and most recently non-stimulants such as atomoxetine has become the one of the first line treatment options. Although we went through a thorough verification process of the safety and efficacy of the medication by contemplating the historical development process, we believe that adjustment is needed for remaining concerns on medication abuse and slight differences in disease paradigm and therapeutic philosophy depending on cultures.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.24 no.1
• /
• pp.21-27
• /
• 2013

Objectives : Dysregulation of the central noradrenergic system may be involved in the pathophysiology of attention-deficit hyperactivity disorder (ADHD). The aim of this study was to examine the differences in pre- and post-treatment cerebral perfusion according to the MspI polymorphisms of the alpha-2A-adrenergic receptor gene (ADRA2A) in children with ADHD. Methods : Thirty seven drug-naive ADHD children (8.9+1.8 years old, M=32, F=5) were genotyped. Baseline single-photon emission computed tomography (SPECT) and clinical assessments were performed for ADHD children. After treatment with methylphenidate for eight weeks, SPECT and clinical assessment were repeated. Results : No differences in baseline clinical assessments or cerebral perfusion were observed according to the MspI genotype. However, after treatment, ADHD children with the G/G genotype at the MspI polymorphism showed hyperperfusion in the right cerebellar declive (p=.001, uncorrected) and hypoperfusion in the left lentiform nucleus and left cingulate gyrus (p<.001 and p=.001, uncorrected), compared to children without the G/G genotype. Conclusion : Although the results of this study should be interpreted cautiously, they suggest a possible role of the MspI polymorphisms of the ADRA2A gene in methylphenidate-induced changes in cerebral perfusion.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.14 no.1
• /
• pp.3-11
• /
• 2003

Attention-deficit/Hyperactivity disorder(ADHD) is the most common psychiatric disorder of childhood and among the most prevalent chronic health conditions affecting school-aged children. Children with ADHD experience significant functional problems, such as school difficulties, academic underachievement, troublesome interpersonal relationships with family members and peers, and low self-esteem. The most widely used pharmacological treatments for ADHD are psychostimulants, such as methylphenidate and amphetamine salts. These medications provide clinical efficacy by increasing the availability of catecholamines, primarily dopamine, in the frontal lobe of the brain. immediate-release(IR) formulations of sychostimulants were among the most effective psychotrophic medications in the psychopharmacological treatment. However, there are some limitations of IR formulations：the short half-life and duration of efficacy, which result in the need for multiple daily dosing and the poor compliance. These limitations have led to the development of once-daily, extended-release(ER) formulations of methylphenidate and amphetamine salts. However, these ER formulations may not be as immediately helpful to ADHD children due to delayed onset of action and the acute tolerance which is the failure to sustain the efficacy with the same concentration of drug as the initial stage of medication. OROS-methylphenidate(Concerta$^{\circledR}$) given once a day produces an ascending-pattern plasma drug level generated by the osmotically released, timed drug-delivery system. These new formulations of the psychostimulants have been shown to be a useful alternative to old stimulant medications through the evidence by the clinical trials.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.27 no.1
• /
• pp.64-71
• /
• 2016

Objectives: The objective of this study was to examine the effects of osmotic-controlled release oral delivery system methylphenidate on changes in regional cerebral blood flow (rCBF) in children with attention-deficit hyperactivity disorder (ADHD) using single photon emission computed tomography (SPECT). Methods: A total of 26 children with ADHD (21 boys, mean age: $9.2{\pm}2.05$ years old) were recruited. Each ADHD participant was examined for changes in rCBF using technetium-99m-hexamethylpropylene amine oxime brain SPECT before and after 8 weeks methylphenidate medication. Brain SPECT images of pediatric normal controls were selected retrospectively. SPECT images of ADHD children taken before medication were compared with those of pediatric normal controls and those taken after medication using statistical parametric mapping analysis on a voxel-wise basis. Results: Before methylphenidate medication, significantly decreased rCBF in the cerebellum and increased rCBF in the right precuneus, left anterior cingulate, right postcentral gyrus, right inferior parietal lobule and right precentral gyrus were observed in ADHD children compared to pediatric normal controls (p-value<.0005, uncorrected). After medication, we observed significant hypoperfusion in the left thalamus and left cerebellum compared to pediatric normal controls (p-value<.0005, uncorrected). In the comparison between before medication and after medication, there was significant hyperperfusion in the superior frontal gyrus and middle frontal gyrus and significant hypoperfusion in the right insula, right caudate, right middle frontal gyrus, left subcallosal gyrus, left claustrum, and left superior temporal gyrus after methylphenidate medication (p-value<.0005, uncorrected). Conclusion: This study supports dysfunctions of fronto-striatal structures and cerebellum in ADHD. We suggest that methylphenidate may have some effects on the frontal lobe, parietal lobe, and cerebellum in children with ADHD.