Journal of Attention Disorders

Objective: To examine dispensing patterns of methylphenidate (MPH) to determine how socioeconomic status (SES), ethnocultural affiliation, and gender affect the medical treatment of ADHD. Method: We reviewed MPH prescription records for year 2011 of children aged 6 to 18, from regional pharmacies serving homogeneous neighborhoods. Results: MPH prescriptions showed an increase in prevalence from 4.2% to 7.5% in the years 2007 to 2011, respectively. Jewish children were four times more likely to be prescribed MPH than Arab children, with significant discrepancies along SES and gender lines (p < .001). Higher SES and male gender were associated with greater use of MPH. General pediatric prescription rates of MPH in all communities increased by 85%, compared with year 2007 statistics (p < .001). Conclusion: Prescription patterns for MPH in children reflect diagnostic patterns of ADHD that appear to be heavily influenced by additive factors of SES, cultural attitudes, and gender. Dispensing data provide valuable information for targeting underserved groups and defining potential areas of abuse.

Objective: To explore the utility of cognitive measures for predicting response of children and adolescents to methylphenidate (MPH). Method: Participants from the International Study to Predict Optimized Treatment–in ADHD (iSPOT-A) completed a cognitive test battery prior to receiving 6 weeks of MPH. The responder criterion was a 25% reduction in ADHD-Rating Scale-IV scores. Receiver Operator Characteristics (ROC) classified non-responders from responders with maximal sensitivity and specificity. Results: Overall, 62% of participants responded to MPH. Response rates for ROC-identified groups ranged from 18% to 85%. Non-responders showed compromised cognition related to switching of attention, sustained attention, planning, and impulsivity. One group of responders were 10 years of age or older and had impaired switching of attention and impulsivity; a second group had enhanced switching of attention, normal or higher Continuous Performance Task (CPT) scores, and above average scores on digit span. Conclusion: Cognitive tests may provide a simple, low-cost tool for treatment planning for children and adolescents with ADHD.

Objective:To investigate the prevalence of ADHD medication prescribing of school-aged children in Hong Kong (HK) from 2001 to 2013 and to compare with other countries. Method: Using the Hong Kong Hospital Authority Clinical Data Analysis and Reporting System, we investigated the epidemiology and prevalence of ADHD medication prescribing. Results: The prevalence of children on ADHD medication increased 14 times throughout the study period—0.072% in 2001 (95% confidence interval [CI] = [0.068%, 0.077%]) to 1.027% (95% CI = [1.008%, 1.047%]) in 2013. Prevalence in females increased at a faster rate than in males. The prescribing trend in kindergarten children (3- to 5-year-old) was relatively steady from 2001 to 2008—0.025% (95% CI = [0.019%, 0.033%]) in 2001—until a marked increase from 2009 to 2013—0.121% (95% CI = [0.105%, 0.139%]) in 2013. Conclusion: The prevalence of ADHD medication prescribing in Hong Kong is increasing but remains lower than most Western countries. However, the prevalence of ADHD medication prescribing for kindergarten children should be monitored to ensure appropriate use.

Objective: The nature of ADHD, especially in adulthood, is not well-understood. Therefore, we explored subcomponents of attention in adult ADHD. Method: Twenty-three adults with ADHD were tested on neurocognitive and visual tracking performance both while on their regular prescription stimulant medication and while abstaining from the medication for 1 day. Pairwise comparisons to 46 two-for-one matched normal controls were made to detect medication-resistant effects of ADHD, and within-participant comparisons were made to detect medication-sensitive effects in patients. Results: Even when on medication, patients performed more poorly than controls on a spatial working memory task, and on visual tracking and simple reaction time tasks immediately following other attention-demanding tasks. Patients’ visual tracking performance degraded while off-medication in a manner consistent with reduced vigilance. Conclusion: There may be persistent cognitive impairments in adult ADHD despite medication. In addition, the benefit of stimulants seems reduced under cognitive fatigue.

Objective: To test whether an optimal dose of Quillivant XR (methylphenidate extended-release oral suspension [MEROS]) would significantly reduce symptoms of ADHD in children. Method: A randomized, double-blind, placebo-controlled, cross-over, efficacy, safety, and tolerability study of MEROS in 45 children aged 6 to 12 years (open-label dose-optimization phase, followed by double-blind cross-over period). Results: MEROS was significantly more efficacious than placebo during double-blind cross-over laboratory classroom days (Swanson, Kotkin, Agler, M-Flynn, and Pelham Rating Scale and Permanent Product Measure of Performance). During the open-label phase, improvements were observed in scores of ADHD Rating Scale-IV, and Clinical Global Impression-Severity and -Improvement Scales. No occurrences of suicidal ideation or behavior were recorded; the most common open-label treatment-emergent adverse events were typical of stimulant use: decreased appetite, insomnia, and abdominal pain. Conclusion: MEROS was efficacious in the treatment of children aged 6 to 12 years with ADHD, with a safety profile similar to that of other extended-release methylphenidate pharmacotherapies.

Objective: To investigate the change of ADHD medication prescriptions in Turkey between 2009 and 2013. Method: Consumption data of ADHD medications, immediate release (IR) methylphenidate (MPH; Ritalin), OROS MPH (Concerta), and atomoxetine (Strattera) were obtained from IMS Health database for the November 2008 to October 2013 period. Defined daily dose (DDD) of each drug was calculated according to WHO definitions and time-series analysis was conducted. Results: There was a significant seasonal effect for prescription of all drugs. Annual use of ADHD medications increased 2.18 times for all ADHD medications combined. DDDs per 1,000 population per day for all ADHD medications were 0.28 in 2009, 0.41 in 2010, 0.52 in 2011, and 0.59 in 2012. OROS MPH represented almost 75% of all ADHD medication utilization. Conclusion: As reported from several other countries, ADHD medication use increased in Turkey. Results suggested that over- and underdiagnosis might be seen at the same time.

Objective: To examine the level of agreement between self- and observer-reported ratings of ADHD symptoms and executive function (EF) behaviors in adults with moderate to severe ADHD and EF deficits. Method: During a 10-week, randomized, double-blind, placebo-controlled study, the effect of lisdexamfetamine dimesylate (LDX) on EF was assessed by self-report and informant report (Behavior Rating Inventory of Executive Function–Adult Version), and ADHD symptoms were assessed by clinician- and informant-rated scales (ADHD Rating Scale IV with adult prompts and Conners’ Adult ADHD Rating Scales–Observer Report: Short Version, respectively). Post hoc analysis used Pearson correlations to assess relationships between self- and informant-rated EF and clinician- and informant-rated ADHD symptoms. Results: Correlations between self-ratings versus informant ratings and clinician versus informant ratings were greater at Week 10/early termination (EF: placebo [0.5231–0.6085], LDX [0.3543–0.5167]; ADHD symptoms: placebo [0.4169], LDX [0.4004]) versus baseline (EF: placebo [0.3208–0.5023], LDX [0.2852–0.3439]; ADHD symptoms: placebo [0.1511], LDX [–0.0408]). Conclusion: LDX improved EF and ADHD symptoms, based on participant, informant, and clinician ratings. Increased rater agreement over time may reflect improved symptom awareness.

Objective: A failure of the anti-phase synchronization between default-mode (DMN) and task-positive networks (TPN) may be involved in a main manifestation of ADHD: moment-to-moment variability. The study investigated whereby methylphenidate may improve TPN/DMN synchronization in ADHD. Method: Eleven drug-naive ADHD children and 11 typically developing (TD) children performed a flanker task during functional magnetic resonance imaging. The ADHD group was scanned without and 1 month later with methylphenidate. The signal was analyzed by independent component analysis. Results: The TD group showed anti-phase DMN/TPN synchronization. The unmedicated ADHD group showed synchronous activity in the posterior DMN only, which was positively correlated with response time variability for the flanker task. Methylphenidate initiated a partial anti-phase TPN/DMN synchronization, reduced variability, and abolished the variability/DMN correlation. Conclusion: Although results should be interpreted cautiously because the sample size is small, they suggest that a failure of the TPN/DMN synchronization could be involved in the moment-to-moment variability in ADHD. Methylphenidate initiated TPN/DMN synchronization, which in turn appeared to reduce variability.