Adherence to psychostimulant medication in children with attention-deficit/hyperactivity disorder: the role of attitudes.

OBJECTIVE: To investigate how attitudes towards psychostimulant medication influence the adherence to psychostimulant treatment in children with Attention-Deficit/Hyperactivity Disorder (ADHD). METHOD: Thirty-three children with ADHD were prospectively recruited to take part in this study. The children and their parents filled questionnaires at both baseline and at a three-month follow-up to assess the severity of ADHD symptoms in the child and attitudes towards psychostimulant medication. Adherence to medication was assessed through standardized interviews of parents. RESULTS: Parental perceived psychosocial benefits of psychostimulant medication at the three-month follow-up were found to be positive predictors of adherence to medication. Parental perceived psychosocial benefits of medication at the three-month follow-up was in turn predicted by parental medication acceptability at three months and child's perceived psychosocial benefits of medication at three-months. CONCLUSION: Improving parents' awareness of psychosocial benefits of psychostimulant medication may increase adherence to psychostimulant medication in children with ADHD. Age of the child and severity of symptoms did not significantly affect medication adherence.

OBJECTIF: Rechercher comment les attitudes à l'égard des psychostimulants influencent l'observance du traitement par psychostimulants chez les enfants souffrant du trouble de déficit de l'attention avec hyperactivité (TDAH). MÉTHODE: Trente-trois enfants souffrant du TDAH ont été recrutés prospectivement pour prendre part à cette étude. Les enfants et leurs parents ont répondu à des questionnaires au départ et au suivi de trois mois afin d'évaluer la gravité des symptômes du TDAH chez l'enfant et les attitudes à l'égard des psychostimulants. L'observance des médicaments a été évaluée par des entrevues normalisées avec les parents. RÉSULTATS: La perception des parents des avantages psychosociaux des psychostimulants au suivi de trois mois s'est révélée être un prédicteur positif de l'observance des médicaments. La perception des parents des avantages psychosociaux des médicaments au suivi de trois mois a été prédite à son tour par l'acceptation parentale des médicaments à trois mois et par la perception de l'enfant des avantages psychosociaux des médicaments à trois mois. CONCLUSION: Sensibiliser davantage les parents aux avantages psychosociaux des psychostimulants peut améliorer l'observance des psychostimulants chez les enfants souffrant du TDAH. L'âge de l'enfant et la gravité des symptômes n'influaient pas significativement sur l'observance des médicaments.

Efficacy of Methylphenidate in ADHD Children across the Normal and the Gifted Intellectual Spectrum.

OBJECTIVE: This study evaluates whether attention-deficit/hyperactivity disorder (ADHD) children with a borderline intelligence quotient (IQ) (70≤FSIQ<80), normal IQ (80≤FSIQ<120) and high IQ (FSIQ≥120) respond differently to psychostimulant treatment. METHOD: 502 children, aged 6 to 12 years, with an IQ range from 70 to 150 participated in a two-week, double-blind, placebo-controlled, crossover methylphenidate (MPH) trial. RESULTS: In addition to differences in socioeconomic background and parental education, higher IQ children were found to present with less severe symptoms. No significant differences were found with regards to treatment response. CONCLUSION: ADHD children within the normal and high levels of intellectual functioning all respond equally to psychostimulant treatment, and that proper medication management is necessary for all children with the disorder.

Relation between therapeutic response and side effects induced by methylphenidate as observed by parents and teachers of children with ADHD.

BACKGROUND: The desired (therapeutic) and undesired (side) effects of methylphenidate might have underlying correlations. The aim of this study was to explore the strength and the possible sources of these correlations. METHODS: One hundred and fifty-seven children with ADHD (6-12 years) were administered placebo and methylphenidate (0.5 mg/kg in a divided b.i.d. dose), each for a one-week period, in a double-blind, crossover trial. Therapeutic response was assessed using the Conners' Global Index for parents (CGI-Parents) and teachers (CGI-Teachers), while side effects were assessed using the Barkley Side Effects Rating Scale (SERS). RESULTS: The side effect profile as assessed by the SERS was similar to that of previous studies with insomnia, decreased appetite, and headaches showing significant treatment effects (p < 0.005). These "somatic/physical" side effects did not correlate with CGI-Parents or CGI-Teachers. However, the side effects of "irritability", "proneness to crying", and "anxiousness" showed significant relationships with CGI-Parents. These "mood/anxiety" side effects showed no significant correlations with the CGI-Teachers. CONCLUSION: The greater "mood/anxiety" side effects on methylphenidate and placebo, the less the parents observe improvement of their children while treated with methylphenidate. This suggests that the correlations between "mood/anxiety" side effects and poor response to treatment may be driven by observer effects rather than biological commonalities between therapeutic and side effects of methylphenidate.

Dopamine transporter 3'UTR VNTR genotype is a marker of performance on executive function tasks in children with ADHD.

BACKGROUND: Attention-Deficit/Hyperactivity Disorder (ADHD) is a heterogeneous disorder from both clinical and pathogenic viewpoints. Executive function deficits are considered among the most important pathogenic pathways leading to ADHD and may index part of the heterogeneity in this disorder. METHODS: To investigate the relationship between the dopamine transporter gene (SLC6A3) 3'-UTR VNTR genotypes and executive function in children with ADHD, 196 children diagnosed with ADHD were sequentially recruited, genotyped, and tested using a battery of three neuropsychological tests aimed at assessing the different aspects of executive functioning. RESULTS: Taking into account a correction for multiple comparisons, the main finding of this study is a significant genotype effect on performances on the Tower of London (F = 6.902, p = 0.009) and on the Wechsler Intelligence Scale for Children, Third Edition (WISC-III) Freedom From Distractibility Index (F = 7.125, p = 0.008), as well as strong trends on Self Ordered Pointing Task error scores (F = 4,996 p = 0.026) and WISC-III Digit Span performance (F = 6.28, p = 0.023). Children with the 9/10 genotype exhibited, on average, a poorer performance on all four measures compared to children with the 10/10 genotype. No effect of genotype on Wisconsin Card Sorting Test measures of performance was detected. CONCLUSION: Results are compatible with the view that SLC6A3 genotype may modulate components of executive function performance in children with ADHD.

COMT Val108/158Met polymorphism and the modulation of task-oriented behavior in children with ADHD.

It has been suggested that the symptoms of attention-deficit/hyperactivity disorder (ADHD), including inattention and/or hyperactivity/impulsivity, translate into deficits in task-oriented behavior or problem-focused activity. The frontosubcortical dopamine pathway has been implicated in ADHD. One of the key modulators of extracellular dopamine levels in the prefrontal cortex is catechol-O-methyltransferase (COMT). The objective of this study was to examine the association of the COMT Val(108/158)Met polymorphism with (1) task-oriented behavior in children with ADHD, and (2) response of this behavior given methylphenidate (MPH) treatment. Children of Caucasian ethnicity, having ADHD (n=188), were assessed using the Restricted Academic Situation Scale (RASS). The RASS uses a simulated academic environment within the research clinic, to assess the child's ability for independent, sustained orientation to an assignment of math problems. Each child was administered placebo and MPH (0.5 mg/kg in a divided b.i.d. dose), each for a 1-week period, in a randomized, double-blind, crossover trial. On day 3 of the respective treatment week, the child was administered placebo/MPH in the clinic, and the acute change in behavior (before and 1 h after treatment) was evaluated on the RASS. Analysis was carried out using mixed model analysis of variance. Significant main effects of COMT genotype (F(2,184)=5.12, p=0.007) and treatment (F(1,184)=44.26, p<0.001) on task-oriented behavior were observed. However, no genotype by treatment interaction was observed. These results suggest that the COMT Val(108/158)Met polymorphism modulates task-oriented behavior, but it does not modulate the response of this behavior with MPH treatment.

Relation of maternal stress during pregnancy to symptom severity and response to treatment in children with ADHD.

OBJECTIVE: There is considerable evidence that maternal stress is associated with behavioural disturbances in offspring. The objective of this study was to examine whether there is an association between the severity of maternal stress during pregnancy and the severity of symptoms of attention-deficit hyperactivity disorder (ADHD). A second objective was to examine whether there is an association between maternal stress and children's response to methylphenidate (MPH). METHODS: Using the Kinney Medical and Gynecological Questionnaire, we assessed 203 children with ADHD, aged between 6 and 12 years, regarding maternal stress during pregnancy. We assessed symptom severity with the Child Behavior Checklist (CBCL) and Conners' Global Index for Parents (CGI-P) and Teachers (CGI-T). Subjects were recruited from the ADHD clinic and the day-treatment program of the Child Psychiatry Department of the Douglas Hospital, Montréal, Quebec. The quality of their therapeutic response was assessed in a double-blind, placebo-controlled randomized 2-week crossover trial of MPH. RESULTS: The most severe symptoms as assessed by the CBCL were found in the moderate stressor group, (p < 0.002), whereas, according to the CGI-P (emotional liability), the most severe symptoms were found in the severe stressor group (p < 0.029). There was no statistically significant difference between degree of response to MPH and level of maternal stress. CONCLUSION: Children with ADHD whose mothers were exposed to moderate and severe stress during pregnancy tend to develop more severe symptoms than children with ADHD whose mothers were not exposed to prenatal stress. It is therefore important to minimize stress in pregnant women.

COMT Val108/158Met gene variant, birth weight, and conduct disorder in children with ADHD.

OBJECTIVE: In a recent study, Thapar and colleagues reported that COMT "gene variant and birth weight predict early-onset antisocial behavior in children" with attention-deficit/hyperactivity disorder. We have attempted to replicate these findings in a group of ADHD children using a similar research design. METHOD: Children (n=191) between 6 and 12 years of age who were diagnosed with ADHD were included in the study. Conduct disorder was diagnosed according to DSM-IV criteria based on clinical evaluation and a structured interview (Diagnostic Interview Schedule for Children-IV). The mother's report on the child's birth weight was used in the analysis. Logistic regression analysis, with genotype and birth weight as independent variables and DSM-IV conduct disorder as the dependent variable, was conducted. RESULTS: No significant main effects of genotype and birth weight or interaction effects on conduct disorder were observed. CONCLUSION: In this sample of children diagnosed with ADHD, we find no association between the COMT ValMet gene variant, birth weight, and conduct disorder. Further investigations are required before using birth weight and COMT genotype as predictors of conduct disorder in children with attention-deficit/hyperactivity disorder, especially given the societal and legal ramifications of conduct disorder.