Faculty Bibliography

OBJECTIVE: The aim of this study was to describe the clinical presentation of preschoolers diagnosed with moderate to severe attention-deficit/hyperactivity disorder (ADHD) recruited for the multisite Preschool ADHD Treatment Study (PATS). The diagnosis and evaluation process will also be described. METHOD: A comprehensive multidimensional, multi-informant assessment protocol was implemented including the semistructured PATS Diagnostic Interview. Parent and teacher-report measures were used to supplement information from interviews. Consensus agreement by a cross-site panel on each participant's diagnoses was required. Analyses were conducted to describe the sample and to test associations between ADHD severity and demographic and clinical variables. RESULTS: The assessment protocol identified 303 preschoolers (3-5.5 years) with moderate to severe ADHD Hyperactive/Impulsive or Combined type. The majority of participants (n = 211, 69.6%) experienced co-morbid disorders, with oppositional defiant disorder, communication disorders, and anxiety disorders being the most common. Participants with co-morbid communication disorders were found to be more anxious and depressed. ADHD severity was found to correlate with more internalizing difficulties and lower functioning. Although boys and girls had similar symptom presentations, younger children had significantly higher ADHD severity. CONCLUSIONS: Preschoolers with moderate to severe ADHD experience high co-morbidity and impairment, which have implications for both assessment and treatment

OBJECTIVE: In children diagnosed with attention-deficit/hyperactivity disorder (ADHD) and their parents, who were participants of the Preschool ADHD Treatment Study (PATS), we assessed the effect of source of DNA (from buccal or blood cells) on the genotyping success rate and allele percentages for the five polymorphisms in three candidate genes (DAT1, DRD4, and SNAP 25) investigated in the PATS pharmacogenetic study of response to stimulant medication. METHOD: At baseline assessment, 241 individuals (113 probands and 128 parents) consented to participate; 144 individuals (52 probands and 92 parents) provided blood samples from venipuncture, and 97 individuals (61 probands and 36 parents) provided buccal samples from cheek swab as specimens for isolation of DNA. Three types of polymorphisms-variable number of tandem repeat (VNTR) polymorphism, tandem duplication polymorphism (TDP), and single nucleotide polymorphism (SNP)-were evaluated, including the DRD4 gene 48-bp VNTR in exon III, the DAT1 gene 40-bp VNTR in 3'-untranslated region, the DRD4 gene TDP 120-bp duplication in the promoter region, the SNAP-25 gene TC-1069 SNP, and the SNAP-25 gene TG-1065 SNP. Standard procedures were used to genotype individuals for each of these five polymorphisms. RESULTS: Using the methods available in 2004, the genotyping success rate was on the average much greater for DNA from blood cells than buccal cells (e.g., 91% vs. 54% in probands). For some polymorphisms (DRD4-VNTR, DRD4-TDP, and SNAP25-TC SNP), allele proportion also varied by blood versus buccal source of DNA (e.g., 26.5% vs. 18.6% for the 7-repeat allele of the DRD4 gene). CONCLUSIONS: The much lower success rate for genotyping based on DNA from buccal than blood cells is likely due to the quality of DNA derived from these two sources. The observed source differences in allele proportion may be due to self-selection related to choice of how specimens were collected (from cheek swab or venipuncture), or to a selective detection of some alleles based on differences in DNA quality

OBJECTIVE: The purpose of this study was to examine the effects of methylphenidate (MPH) on functional outcomes, including children's social skills, classroom behavior, emotional status, and parenting stress, during the 4-week, double-blind placebo controlled phase of the Preschoolers with Attention Deficit/Hyperactivity Disorder (ADHD) Treatment Study (PATS). METHODS: A total of 114 preschoolers who had improved with acute MPH treatment, were randomized to their best MPH dose (M = 14.22 mg/day; n = 63) or placebo (PL; n = 51). Assessments included the Clinical Global Impression-Severity (CGI-S), parent and teacher versions of the Strengths and Weaknesses of ADHD-Symptoms and Normal Behaviors (SWAN), Social Competence Scale (SCS), Social Skills Rating System (SSRS), and Early Childhood Inventory (ECI), and Parenting Stress Index (PSI). RESULTS: Medication effects varied by informant and outcome measure. Parent measures and teacher SWAN scores did not differentially improve with MPH. Parent-rated depression (p < 0.02) and dysthymia (p < 0.001) on the ECI worsened with MPH, but scores were not in the clinical range. Significant medication effects were found on clinician CGI-S (p < 0.0001) and teacher social competence ratings (SCS, p < 0.03). CONCLUSIONS: Preschoolers with ADHD treated with MPH for 4 weeks improve in some aspects of functioning. Additional improvements might require longer treatment, higher doses, and/or intensive behavioral treatment in combination with medication

OBJECTIVE: The aim of this study was to examine immediate-release methylphenidate effectiveness during the 10-month open-label continuation phase of the Preschoolers with Attention-Deficit/Hyperactivity Disorder (ADHD) Treatment Study (PATS). METHODS: One hundred and forty preschoolers with ADHD, who had improved with acute immediate-release methylphenidate (IR-MPH) treatment, entered a 10-month, open-label medication maintenance at six sites. Assessments included the Clinical Global Impression-Severity (CGI-S), CGI-Improvement (CGI-I), Children's Global Assessment Scale (C-GAS), Swanson, Nolan, and Pelham Questionnaire (SNAP), Scale Strengths and Weaknesses of ADHD-Symptoms and Normal Behaviors (SWAN), Social Competence Scale, Social Skills Rating System (SSRS), and Parenting Stress Index-Short Form (PSI-SF). RESULTS: For the 95 children who completed the 10-month treatment, improvement occurred on the CGI-S (p = 0.02), CGI-I (p < 0.01), C-GAS (p = 0.001), and SSRS (p = 0.01). SNAP and SWAN scores remained stable. Forty five children discontinued: 7 for adverse effects, 7 for behavior worsening, 7 for switching to long-acting stimulants, 3 for inadequate benefit, and 21 for other reasons. The mean MPH dose increased from 14.04 mg/day +/- SD 7.57 (0.71 +/- 0.38 mg/kg per day) at month 1 to 19.98 mg/day +/- 9.56 (0.92 +/- 0.40 mg/kg per day) at month 10. CONCLUSIONS: With careful monitoring and gradual medication dose increase, most preschoolers with ADHD maintained improvement during long-term IR-MPH treatment. There was substantial variability in effective and tolerated dosing

OBJECTIVE: The aim of this study was to examine whether demographic or pretreatment clinical and social characteristics influenced the response to methylphenidate (MPH) in the Preschoolers with ADHD Treatment Study (PATS). METHODS: Exploratory moderator analyses were conducted on the efficacy data from the PATS 5-week, double-blind, placebo-controlled six-site titration trial. Children (N = 165, age 3-5.5 years) were randomized to 1 week each of four MPH doses (1.25, 2.5, 5, and 7.5 mg) and placebo administered three times per day (t.i.d.). We assessed the fixed effects on the average slope in the regression outcome on moderators, weight-adjusted dose, and the moderator-by-dose interaction using SAS PROC GENMOD. RESULTS: A significant interaction effect was found for a number of co-morbid disorders diagnosed in the preschoolers at baseline (p = 0.005). Preschoolers with three or more co-morbid disorders did not respond to MPH (Cohen's d at 7.5 mg dose relative to placebo = -0.37) compared to a significant response in the preschoolers with 0, 1, or 2 co-morbid disorders (Cohen's d = 0.89, 1.00, and 0.56, respectively). Preschoolers with more co-morbidity were found to have more family adversity. No significant interaction effect was found with the other variables. CONCLUSIONS: In preschoolers with ADHD, the presence of no or one co-morbid disorder (primarily oppositional defiant disorder) predicted a large treatment response at the same level as has been found in school-aged children, and two co-morbid disorders predicted moderate treatment response; whereas the presence of three or more co-morbid disorders predicted no treatment response to MPH

OBJECTIVE: This study examines one-, two-, and three-factor models of attention-deficit/hyperactivity disorder (ADHD) using the existing 18 Diagnostic and Statistical Manual of Mental Disorder, 4th edition (DSM-IV) symptoms in a sample of symptomatic preschoolers. METHODS: Parent and/or teacher ratings of DSM-IV symptoms were obtained for 532 children (aged 3-5.5) who were screened for the Preschool ADHD Treatment Study (PATS). Confirmatory factor analysis (CFA) using symptoms identified on the Conners' Parent and Teacher Rating Scales was conducted to assess a two-factor model representing the DSM-IV dimensions of inattention (IN) and hyperactivity/impulsivity (H/I), a three-factor model reflecting inattention, hyperactivity, and impulsivity, and a single-factor model of all ADHD symptoms. Exploratory factor analysis (EFA) was subsequently used to examine the latent structure of the data. RESULTS: For parent ratings, the two-factor and three-factor models were marginally acceptable according to several widely used fit indices, whereas the one-factor model failed to meet minimum thresholds for goodness-of-fit. For teachers, none of the models was a solid fit for the data. Maximum likelihood EFAs resulted in satisfactory two and three-factor models for both parents and teachers, although all models contained several moderate cross loadings. Factor loadings were generally concordant with those published for older children and community-based samples. CONCLUSION: ADHD subtypes according to current DSM-IV specifications may not be the best descriptors of the disorder in the preschool age group

OBJECTIVE: To compare delinquent behavior and early substance use between the children in the Multimodal Treatment Study of Children With ADHD (MTA; N = 487) and those in a local normative comparison group (n = 272) at 24 and 36 months postrandomization and to test whether these outcomes were predicted by the randomly assigned treatments and subsequent self-selected prescribed medications. METHOD: Most MTA children were 11 to 13 years old by 36 months. Delinquency seriousness was coded ordinally from multiple measures/reporters; child-reported substance use was binary. RESULTS: Relative to local normative comparison group, MTA children had significantly higher rates of delinquency (e.g., 27.1% vs. 7.4% at 36 months; p = .000) and substance use (e.g., 17.4% vs. 7.8% at 36 months; p = .001). Children randomized to intensive behavior therapy reported less 24-month substance use than other MTA children (p = .02). Random effects ordinal growth models revealed no other effects of initial treatment assignment on delinquency seriousness or substance use. By 24 and 36 months, more days of prescribed medication were associated with more serious delinquency but not substance use. CONCLUSIONS: Cause-and-effect relationships between medication treatment and delinquency are unclear; the absence of associations between medication treatment and substance use needs to be re-evaluated at older ages. Findings underscore the need for continuous monitoring of these outcomes as children with attention-deficit/hyperactivity disorder enter adolescence

OBJECTIVE: To evaluate the hypothesis of stimulant medication effect on physical growth in the follow-up phase of the Multimodal Treatment Study of Children With ADHD. METHOD: Naturalistic subgroups were established based on patterns of treatment with stimulant medication at baseline, 14-, 24-, and 36-month assessments: not medicated (n = 65), newly medicated (n = 88), consistently medicated (n = 70), and inconsistently medicated (n = 147). Analysis of variance was used to evaluate effects of subgroup and assessment time on measures of relative size (z scores) obtained from growth norms. RESULTS: The subgroup x assessment time interaction was significant for z height (p <.005) and z weight (p <.0001), due primarily to divergence of the newly medicated and the not medicated subgroups. These initially stimulant-naive subgroups had z scores significantly >0 at baseline. The newly medicated subgroup showed decreases in relative size that reached asymptotes by the 36-month assessment, when this group showed average growth of 2.0 cm and 2.7 kg less than the not medicated subgroup, which showed slight increases in relative size. CONCLUSIONS: Stimulant-naive school-age children with Combined type attention-deficit/hyperactivity disorder were, as a group, larger than expected from norms before treatment but show stimulant-related decreases in growth rates after initiation of treatment, which appeared to reach asymptotes within 3 years without evidence of growth rebound

OBJECTIVE: To evaluate two hypotheses: that self-selection bias contributed to lack of medication advantage at the 36-month assessment of the Multimodal Treatment Study of Children With ADHD (MTA) and that overall improvement over time obscured treatment effects in subgroups with different outcome trajectories. METHOD: Propensity score analyses, using baseline characteristics and severity of attention-deficit/hyperactivity disorder symptoms at follow-up, established five subgroups (quintiles) based on tendency to take medication at the 36-month assessment. Growth mixture model (GMM) analyses were performed to identify subgroups (classes) with different patterns of outcome over time. RESULTS: All five propensity subgroups showed initial advantage of medication that disappeared by the 36-month assessment. GMM analyses identified heterogeneity of trajectories over time and three classes: class 1 (34% of the MTA sample) with initial small improvement followed by gradual improvement that produced significant medication effects; class 2 (52%) with initial large improvement maintained for 3 years and overrepresentation of cases treated with the MTA Medication Algorithm; and class 3 (14%) with initial large improvement followed by deterioration. CONCLUSIONS: We failed to confirm the self-selection hypothesis. We found suggestive evidence of residual but not current benefits of assigned medication in class 2 and small current benefits of actual treatment with medication in class 1

OBJECTIVE: In the intent-to-treat analysis of the Multimodal Treatment Study of Children With ADHD (MTA), the effects of medication management (MedMgt), behavior therapy (Beh), their combination (Comb), and usual community care (CC) differed at 14 and 24 months due to superiority of treatments that used the MTA medication algorithm (Comb+MedMgt) over those that did not (Beh+CC). This report examines 36-month outcomes, 2 years after treatment by the study ended. METHOD: For primary outcome measures (attention-deficit/hyperactivity disorder [ADHD] and oppositional defiant disorder [ODD] symptoms, social skills, reading scores, impairment, and diagnostic status), mixed-effects regression models and orthogonal contrasts examined 36-month outcomes. RESULTS: At 3 years, 485 of the original 579 subjects (83.8%) participated in the follow-up, now at ages 10 to 13 years, (mean 11.9 years). In contrast to the significant advantage of MedMgt+Comb over Beh+CC for ADHD symptoms at 14 and 24 months, treatment groups did not differ significantly on any measure at 36 months. The percentage of children taking medication >50% of the time changed between 14 and 36 months across the initial treatment groups: Beh significantly increased (14% to 45%), MedMed+Comb significantly decreased (91% to 71%), and CC remained constant (60%-62%). Regardless of their treatment use changes, all of the groups showed symptom improvement over baseline. Notably, initial symptom severity, sex (male), comorbidity, public assistance, and parental psychopathology (ADHD) did not moderate children's 36-month treatment responses, but these factors predicted worse outcomes over 36 months, regardless of original treatment assignment. CONCLUSIONS: By 36 months, the earlier advantage of having had 14 months of the medication algorithm was no longer apparent, possibly due to age-related decline in ADHD symptoms, changes in medication management intensity, starting or stopping medications altogether, or other factors not yet evaluated