Search

Several lines of evidence suggest a relevant role for the dopamine transporter (DAT1) gene not only as a susceptibility factor for attention-deficit hyperactivity disorder (ADHD), but also as a predictor of individual methylphenidate (MPH) response. Pharmacogenetic studies of MPH response in ADHD have mainly focused on the 40-bp variable number of tandem repeats (VNTR) in the 3′ untranslated region (3′-UTR) of DAT1. Most studies were performed in samples of children and conflicting findings were obtained. Only two studies have assessed 3′-VNTR in samples of adults—one with positive and the other with negative findings. In the present study, we investigate three potentially relevant polymorphisms in DAT1 gene (−839 C > T; Int8 VNTR and 3′-VNTR), and their possible role in therapeutic response to MPH treatment in a sample of 171 Brazilian adults with ADHD. The diagnostic procedures followed the DSM-IV criteria and the outcome measures were the scales Swanson, Nolan, and Pelham Rating scale version IV and the Clinical Global Impression-Severity Scale, applied at the beginning and after the 30th day of treatment. Drug response was assessed by both categorical and dimensional approaches. There was no effect of any DAT1 polymorphisms or haplotypes on MPH response. This is the second report demonstrating absence of differences in MPH response according to DAT1 genotypes in adults with ADHD. Although DAT protein is crucial for the effect of MPH, genetic variations in DAT1 gene probably do not have a significant clinical role in this sample of adults with ADHD. [ABSTRACT FROM AUTHOR]

The aim of the present study is to verify if gender modifies the clinical, adaptative and psychological outcomes of adult attention–deficit/hyperactivity disorder (ADHD) subtypes. We evaluated 219 clinically referred adult patients. The interviews followed the DSM–IV criteria,using the K–SADS–E for ADHD and oppositional defiant disorder and SCID–IV for comorbidities. Regression models were used to analyze gender and subtype main effects and interactions in psychiatric outcomes. In the initial sample, 117 patients (53.5%) were of the combined subtype, 88 (40%) were inattentives and 14 (6.5%) hyperactives. There were no significant interactions between gender and subtype in any variable assessed. Men and women did not differ in the relative frequency of each subtype. Patients of the combined subtype in both genders presented a higher severity and increased rates of conduct and ODD disorders than inattentives. The main effects of gender and subtype in this sample are similar to those previously reported in other countries, suggesting the cross–cultural equivalence of the phenotype. The absence of significant interactions between gender and subtype suggests that, at least in clinical–based samples, DSM–IV adult ADHD subtypes present cross–gender validity. [ABSTRACT FROM AUTHOR]

Introduction and objective: The evaluation of methylphenidate (MPH) response in patients with ADHD has rarely evaluated the effect of comorbidities [1]. The aim of this study is to evaluate response to MPH in patients with ADHD and comorbid disorders. Methods: Sociodemographic variables, comorbidity status and response to MPH were evaluated in 164 patients with ADHD. The analyses were restricted to subjects whose comorbidities did not demand specific treatment before the use of MPH. Results: The diagnosis of current oppositional defiant disorder (ODD) was associated to a larger decrease in inattention (p = 0.05), hyperactivity (p = 0.006) and ODD SNAP scores (p\0.001) following MPH. After adjustment for basal scores, the only dimension that remained significant was SNAP ODD (p = 0.05). Other comorbidities did not present significant effects. Discussion: Overall, the presence of comorbidities does not have a major influence in response to MPH. However, patients with current ODD have a larger decrease in SNAP scores, especially in ODD scores. This effect is mainly explained by pre-treatment severity. Conclusions: These results reinforce the evidence suggesting that MPH may be effective in ODD treatment. [ABSTRACT FROM AUTHOR]