Examining Patterns and Predictors of ADHD Teens' Skill-Learning Trajectories During Enhanced FOrward Concentration and Attention Learning (FOCAL+) Training.

OBJECTIVE: Examine patterns and predictors of skill learning during multisession Enhanced FOrward Concentration and Attention Learning (FOCAL+) training. BACKGROUND: FOCAL+ teaches teens to reduce the duration of off-road glances using real-time error learning. In a randomized controlled trial, teens with ADHD received five sessions of FOCAL+ training and demonstrated significant reductions in extended glances (>2-s) away from the roadway (i.e., long-glances) and a 40% reduced risk of a crash/near-crash event. Teens' improvement in limiting long-glances as assessed after each FOCAL+ training session has not been examined. METHOD: Licensed teen (ages 16-19) drivers with ADHD (n = 152) were randomly assigned to five sessions of either FOCAL+ or modified standard driver training. Teens completed driving simulation assessments at baseline, after each training session, and 1 month and 6 months posttraining. Naturalistic driving was monitored for one year. RESULTS: FOCAL+ training produced a 53% maximal reduction in long-glances during postsession simulated driving. The number of sessions needed to achieve maximum performance varied across participants. However, after five FOCAL+ training sessions, number of long-glances was comparable irrespective of when teens achieved their maximum performance. The magnitude of reduction in long-glances predicted levels of long-glances during simulated driving at 1 month and 6 months posttraining but not naturalistic driving outcomes. FOCAL+ training provided the most benefit during training to teens who were younger and had less driving experience. CONCLUSION: FOCAL+ training significantly reduces long-glances beginning at the 1st training session. APPLICATION: Providing five FOCAL+ training sessions early on during teen driving may maximize benefit.

Preliminary examination of ADHD inattentive and cognitive disengagement syndrome symptoms in relation to probe-caught mind-wandering during a sustained attention to response task.

OBJECTIVE: The role of mind-wandering- periods of internally-directed distractibility - among patients with attention-deficit/hyperactivity disorder (ADHD) has recently garnered attention, though few studies have assessed mind-wandering using thought probes during a sustained attention to response task (SART) or examined the possible role of cognitive disengagement syndrome (CDS) symptoms. We examined whether parent- and/or teacher-reported ADHD-inattentive (ADHD-IN) or CDS symptoms were independently associated with probe-caught mind-wandering. METHODS: Fifty-four children (ages 9-12; 35.2% female) completed a SART with thought probes inquiring about various on- and off-task thoughts, including mind-wandering and distraction. Questionnaires provided information on demographics, medication treatment, and parent- and teacher-reported ADHD-IN and CDS symptoms. Regression models were estimated separately by informant to examine whether ADHD-IN or CDS symptoms were uniquely associated with mind-wandering or distraction frequency during the SART. RESULTS: Higher teacher-reported CDS ratings, but not ADHD-IN ratings, were uniquely associated with more probe-caught mind-wandering. No significant findings related to parent-reported symptoms or probe-caught distraction were observed. CONCLUSIONS: These preliminary findings add to an emerging body of work pointing to CDS as more consistently or strongly associated than ADHD-IN with mind-wandering. Theoretical and clinical implications are discussed.

Executive Functioning as a Predictor of Adverse Driving Outcomes in Teen Drivers With ADHD.

OBJECTIVE: The present study examined the association between executive functioning (EF) and risky driving behaviors in teens with ADHD. METHOD: Teens diagnosed with ADHD (n = 179; Mage = 17.4 years) completed two 15-min drives in a fixed-base driving simulator. EF was assessed using parent- and self-report Behavior Rating Inventory of Executive Functioning (BRIEF-2), a temporal reproduction task, and a Go/No-Go task (GNG). Driving outcomes included known predictors of crashes: count of long (>2 s) off-road glances, standard deviation (SD) of lane position (SDLP), mean speed, and SD speed. Generalized linear mixed models, controlling for intelligence and driving experience, were conducted. RESULTS: Higher rates of GNG commission errors predicted higher rates of long off-road glances. Lower parent-rated EF and increased rates of GNG omission errors predicted SDLP. Higher rates of GNG commission errors also predicted faster average driving speed. CONCLUSION: Heterogeneity in EF is associated with differences in teen ADHD risky driving behaviors.

ABCD_Harmonizer: An Open-source Tool for Mapping and Controlling for Scanner Induced Variance in the Adolescent Brain Cognitive Development Study.

Data from multisite magnetic resonance imaging (MRI) studies contain variance attributable to the scanner that can reduce statistical power and potentially bias results if not appropriately managed. The Adolescent Cognitive Brain Development (ABCD) study is an ongoing, longitudinal neuroimaging study acquiring data from over 11,000 children starting at 9-10 years of age. These scans are acquired on 29 different scanners of 5 different model types manufactured by 3 different vendors. Publicly available data from the ABCD study include structural MRI (sMRI) measures such as cortical thickness and diffusion MRI (dMRI) measures such as fractional anisotropy. In this work, we 1) quantify the variance attributable to scanner effects in the sMRI and dMRI datasets, 2) demonstrate the effectiveness of the data harmonization approach called ComBat to address scanner effects, and 3) present a simple, open-source tool for investigators to harmonize image features from the ABCD study. Scanner-induced variance was present in every image feature and varied in magnitude by feature type and brain location. For almost all features, scanner variance exceeded variability attributable to age and sex. ComBat harmonization was shown to effectively remove scanner induced variance from all image features while preserving the biological variability in the data. Moreover, we show that for studies examining relatively small subsamples of the ABCD dataset, the use of ComBat harmonized data provides more accurate estimates of effect sizes compared to controlling for scanner effects using ordinary least squares regression.

Examining reaction time variability on the stop-signal task in the ABCD study.

OBJECTIVE: Reaction time variability (RTV) has been estimated using Gaussian, ex-Gaussian, and diffusion model (DM) indices. Rarely have studies examined interrelationships among these performance indices in childhood, and the use of reaction time (RT) computational models has been slow to take hold in the developmental psychopathology literature. Here, we extend prior work in adults by examining the interrelationships among different model parameters in the ABCD sample and demonstrate how computational models of RT can clarify mechanisms of time-on-task effects and sex differences in RTs. METHOD: This study utilized trial-level data from the stop signal task from 8916 children (9-10 years old) to examine Gaussian, ex-Gaussian, and DM indicators of RTV. In addition to describing RTV patterns, we examined interrelations among these indicators, temporal patterns, and sex differences. RESULTS: There was no one-to-one correspondence between DM and ex-Gaussian parameters. Nonetheless, drift rate was most strongly associated with standard deviation of RT and tau, while nondecisional processes were most strongly associated with RT, mu, and sigma. Performance worsened across time with changes driven primarily by decreasing drift rate. Boys were faster and less variable than girls, likely attributable to girls' wide boundary separation. CONCLUSIONS: Intercorrelations among model parameters are similar in children as has been observed in adults. Computational approaches play a crucial role in understanding performance changes over time and can also clarify mechanisms of group differences. For example, standard RT models may incorrectly suggest slowed processing speed in girls that is actually attributable to other factors.

Trial of Training to Reduce Driver Inattention in Teens with ADHD.

BACKGROUND: Teens with attention deficit-hyperactivity disorder (ADHD) are at increased risk for motor vehicle collisions. A computerized skills-training program to reduce long glances away from the roadway, a contributor to collision risk, may ameliorate driving risks among teens with ADHD. METHODS: We evaluated a computerized skills-training program designed to reduce long glances (lasting ≥2 seconds) away from the roadway in drivers 16 to 19 years of age with ADHD. Participants were randomly assigned in a 1:1 ratio to undergo either enhanced Focused Concentration and Attention Learning, a program that targets reduction in the number of long glances (intervention) or enhanced conventional driver's education (control). The primary outcomes were the number of long glances away from the roadway and the standard deviation of lane position, a measure of lateral movements away from the center of the lane, during two 15-minute simulated drives at baseline and at 1 month and 6 months after training. Secondary outcomes were the rates of long glances and collisions or near-collisions involving abrupt changes in vehicle momentum (g-force event), as assessed with in-vehicle recordings over the 1-year period after training. RESULTS: During simulated driving after training, participants in the intervention group had a mean of 16.5 long glances per drive at 1 month and 15.7 long glances per drive at 6 months, as compared with 28.0 and 27.0 long glances, respectively, in the control group (incidence rate ratio at 1 month, 0.64; 95% confidence interval [CI], 0.52 to 0.76; P<0.001; incidence rate ratio at 6 months, 0.64; 95% CI, 0.52 to 0.76; P<0.001). The standard deviation of lane position (in feet) was 0.98 SD at 1 month and 0.98 SD at 6 months in the intervention group, as compared with 1.20 SD and 1.20 SD, respectively, in the control group (difference at 1 month, -0.21 SD; 95% CI, -0.29 to -0.13; difference at 6 months, -0.22 SD; 95% CI, -0.31 to -0.13; P<0.001 for interaction for both comparisons). During real-world driving over the year after training, the rate of long glances per g-force event was 18.3% in the intervention group and 23.9% in the control group (relative risk, 0.76; 95% CI, 0.61 to 0.92); the rate of collision or near-collision per g-force event was 3.4% and 5.6%, respectively (relative risk, 0.60, 95% CI, 0.41 to 0.89). CONCLUSIONS: In teens with ADHD, a specially designed computerized simulated-driving program with feedback to reduce long glances away from the roadway reduced the frequency of long glances and lessened variation in lane position as compared with a control program. During real-world driving in the year after training, the rate of collisions and near-collisions was lower in the intervention group. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT02848092.).

Academic functioning in children with and without sluggish cognitive tempo.

Sluggish cognitive tempo (SCT) is increasingly conceptualized as a transdiagnostic set of symptoms associated with poorer functional outcomes, although the extent to which SCT is associated with academic functioning remains unclear. This study recruited children based on the presence or absence of clinically elevated SCT symptoms, using a multi-informant and multi-method design to provide a comprehensive examination of academic functioning in children with and without clinically elevated SCT symptoms. Participants were 207 children in Grades 2-5 (ages 7-11 years; 63.3% male), including 103 with clinically elevated teacher-reported SCT symptoms and 104 without elevated SCT, closely matched on grade and sex. A multi-informant, multi-method design that included standardized achievement testing, curriculum-based measurement (CBM), grades, classroom and laboratory observations, and parent and teacher rating scales was used. Children with elevated SCT symptoms had poorer academic functioning than their peers across most domains examined. Specifically, compared to children without SCT, children with elevated SCT had significantly lower grade point average (d = 0.42) and standardized achievement scores (ds = 0.40-0.77), poorer CBM performance including lower productivity (ds = 0.39-0.51), poorer homework performance and organizational skills (ds = 0.58-0.85), and lower teacher-reported academic skills (ds = 0.63-0.74) and academic enablers (ds = 0.66-0.74). The groups did not significantly differ on percentage of time on task during classroom observations or academic enabler interpersonal skills. Most effects were robust to control of family income, medication use, and attention-deficit/hyperactivity disorder inattentive symptoms, although effects for motivation and study skills academic enablers were reduced. This study demonstrates that children with clinically elevated SCT symptoms have wide-ranging academic difficulties compared to their peers without SCT. Findings point to the potential importance of assessing and treating SCT to improve academic outcomes.

Shortened Sleep Duration Causes Sleepiness, Inattention, and Oppositionality in Adolescents With Attention-Deficit/Hyperactivity Disorder: Findings From a Crossover Sleep Restriction/Extension Study.

OBJECTIVE: Although poor sleep is often reported in adolescents with attention-deficit/hyperactivity disorder (ADHD), prior studies have been correlational. This study investigated whether sleep duration is causally linked to sleepiness, inattention, and behavioral functioning in adolescents with ADHD. METHOD: A total of 72 adolescents (aged 14-17 years) entered a 3-week sleep protocol using an experimental crossover design. The protocol included a phase stabilization week, followed in randomized counterbalanced order by 1 week of sleep restriction (6.5 hours) and 1 week of sleep extension (9.5 hours). Sleep was monitored with actigraphy and daily sleep diaries, with laboratory visits at the end of each week. Analyses included 48 adolescents who had complete actigraphy data and successfully completed the sleep protocol (defined a priori as obtaining ≥1 hour actigraphy-measured sleep duration during extension compared to restriction). Parent and adolescent ratings of daytime sleepiness, ADHD symptoms, sluggish cognitive tempo (SCT), and oppositional behaviors were the primary measures. The A-X Continuous Performance Test (CPT) was a secondary measure. RESULTS: Compared to the extended sleep week, parents reported more inattentive and oppositional symptoms during the restricted sleep week. Both parents and adolescents reported more SCT symptoms and greater daytime sleepiness during restriction compared to extension. Adolescents reported less hyperactivity-impulsivity during sleep restriction than extension. No effects were found for parent-reported hyperactivity-impulsivity, adolescent-reported ADHD inattention, or CPT performance. CONCLUSION: This study provides the first evidence that sleep duration is a causal contributor to daytime behaviors in adolescents with ADHD. Sleep may be an important target for intervention in adolescents with ADHD. CLINICAL TRIAL REGISTRATION INFORMATION: Cognitive and Behavioral Effects of Sleep Restriction in Adolescents With ADHD; https://clinicaltrials.gov/; NCT02732756.

Reasons Why Children and Adolescents With Attention-Deficit/Hyperactivity Disorder Stop and Restart Taking Medicine.

OBJECTIVE: To describe the prevalence of reasons why children and adolescents stop and restart attention-deficit/hyperactivity disorder (ADHD) medicine and whether functional impairment is present after stopping medicine. METHODS: We used the prospective longitudinal cohort from the Multimodal Treatment of Study of Children With ADHD. At the 12-year follow-up, when participants were a mean of 21.1 years old, 372 participants (76% male, 64% white) reported ever taking ADHD medicine. Participants reported the age when they last stopped and/or restarted ADHD medicine and also endorsed reasons for stopping and restarting. RESULTS: Seventy-seven percent (286 of 372) reported stopping medicine for a month or longer at some time during childhood or adolescence. Participants were a mean of 13.3 years old when they last stopped medicine. The most commonly endorsed reasons for stopping medication related to 1) medicine not needed/helping, 2) adverse effects, 3) logistical barriers of getting or taking medication, and 4) social concerns or stigma. Seventeen percent (64 of 372) reported restarting medicine after stopping for a month or longer. Commonly endorsed reasons for restarting related to medicine being needed or medicine helping; and resolution of logistical barriers to getting or taking medicine. For both stopping and restarting, the proportion endorsing some reasons differed by age range, with the overall pattern suggesting that parental involvement in decisions decreased with age. Nearly all participants had impairment at the assessment after stopping, regardless of whether medication was resumed. CONCLUSIONS: Different reasons for stopping and/or restarting medicine are relevant at different times for different teens. Tailored strategies may help engage adolescents as full partners in their treatment plan.

Does Sluggish Cognitive Tempo Fit Within a Bi-Factor Model of ADHD?

OBJECTIVE: Studies demonstrate sluggish cognitive tempo (SCT) symptoms to be distinct from inattentive and hyperactive-impulsive dimensions of ADHD. No study has examined SCT within a bi-factor model of ADHD, whereby SCT may form a specific factor distinct from inattention and hyperactivity/impulsivity while still fitting within a general ADHD factor, which was the purpose of the current study. METHOD: A total of 168 children were recruited from an ADHD clinic. Most (92%) met diagnostic criteria for ADHD. Parents and teachers completed measures of ADHD and SCT. RESULTS: Although SCT symptoms were strongly associated with inattention, they loaded onto a factor independent of ADHD g. Results were consistent across parent and teacher ratings. CONCLUSION: SCT is structurally distinct from inattention as well as from the general ADHD latent symptom structure. Findings support a growing body of research suggesting SCT to be distinct and separate from ADHD.

Parent-teacher agreement on ADHD symptoms across development.

Parent-teacher agreement on attention-deficit/hyperactivity disorder (ADHD) symptom ratings ranges from low to moderate. Most studies evaluating parent-teacher agreement have not assessed measurement invariance across raters. Hence, it is unclear whether discordance across raters is due to differing ADHD constructs across raters or other factors (e.g., subjective differences across raters). Additionally, the effect of development on parent-teacher agreement is relatively unknown. To address these limitations, the present study used parent and teacher ADHD ratings from a large (N = 6,659) developmentally diverse (ages 4-17) sample. Using exploratory structural equation modeling on half the sample, and then confirmatory factor analysis (CFA) on the other half of the sample, confirmed a 2-factor structure with significant cross-loadings for the 18 ADHD symptoms. CFA invariance analyses demonstrated that the 2-factor symptom structure was similar across raters and age groups. After confirming measurement invariance, the correlation between latent factors within and across raters was examined for each age group as well as across age groups. Parents reported greater severity of ADHD symptoms than did teachers, and both parents and teachers reported higher levels of hyperactivity/impulsivity in younger children than in older children and consistent levels of inattention across development. Finally, correlations between parent-teacher ratings of like factors were weak for inattention and moderate-strong for hyperactivity/impulsivity, and the magnitude of parent-teacher agreement did not vary across development. In conclusion, while parent and teacher ratings of ADHD behaviors are only weakly to moderately correlated, each reporter provides unique and valid clinical information as it relates to ADHD symptom presentation.

Mediators of methylphenidate effects on math performance in children with attention-deficit hyperactivity disorder.

OBJECTIVE: Stimulant medications, such as methylphenidate (MPH), improve the academic performance of children with attention-deficit hyperactivity disorder (ADHD). However, the mechanism by which MPH exerts an effect on academic performance is unclear. We examined MPH effects on math performance and investigated possible mediation of MPH effects by changes in time on-task, inhibitory control, selective attention, and reaction time variability. METHODS: Children with ADHD aged 7 to 11 years (N = 93) completed a timed math worksheet (with problems tailored to each individual's level of proficiency) and 2 neuropsychological tasks (Go/No-Go and Child Attention Network Test) at baseline, then participated in a 4-week, randomized, controlled, titration trial of MPH. Children were then randomly assigned to their optimal MPH dose or placebo for 1 week (administered double-blind) and repeated the math and neuropsychological tasks (posttest). Baseline and posttest videorecordings of children performing the math task were coded to assess time on-task. RESULTS: Children taking MPH completed 23 more math problems at posttest compared to baseline, whereas the placebo group completed 24 fewer problems on posttest versus baseline, but the effects on math accuracy (percent correct) did not differ. Path analyses revealed that only change in time on-task was a significant mediator of MPH's improvements in math productivity. CONCLUSIONS: MPH-derived math productivity improvements may be explained in part by increased time spent on-task, rather than improvements in neurocognitive parameters, such as inhibitory control, selective attention, or reaction time variability.

The myADHDportal.com Improvement Program: An innovative quality improvement intervention for improving the quality of ADHD care among community-based pediatricians.

Though the American Academy of Pediatrics has developed and disseminated clear evidence-based guidelines for ADHD care, community-based pediatricians often have difficulty implementing these guidelines. New strategies are needed to improve the quality of care received by children with ADHD and to improve utilization of the AAP consensus guidelines by pediatricians. An evidence-based quality improvement intervention has been developed that effectively improves the quality of ADHD care delivered by community-based pediatricians. In order to facilitative widespread dissemination of this intervention model, the entire intervention has been modified for online delivery. The intervention is called the myADHDportal.com Improvement Program. The full functionality of this online intervention is described including the collection of online ADHD rating scales from parents and teachers and online communication between parents, teachers, and physicians. In addition, the web portal integrates several innovative quality improvement features including an online wizard for mapping ADHD patient flow, an online report card for monitoring quality of care, and an online wizard for guiding practices through the Plan-Do-Study-Act (PDSA) cycle process. The combination of clinical utility and quality improvement tools facilitates delivery of quality ADHD care and reduces several of the obstacles to implementing AAP-recommended practice behaviors. Initial results with this intervention model are reviewed and goals for dissemination are described.

Use of an Internet portal to improve community-based pediatric ADHD care: a cluster randomized trial.

OBJECTIVE: To determine the effectiveness of a quality improvement program to improve pediatricians' adherence to existing, evidence-based, attention-deficit/hyperactivity disorder (ADHD) practice guidelines. METHODS: Forty-nine community-based pediatricians at 8 practices participated in a cluster-randomized trial. Practices were matched according to the numbers of pediatricians and the proportions of patients receiving Medicaid. The medical charts for a random sample of patients with ADHD for each of the participating pediatricians were examined at baseline and 6 months. All practices participated in 4 sessions of training, including didactic lectures and office flow modification workshops. Practices were then given access to an ADHD Internet portal that allowed parents, teachers, and pediatricians to input information (eg, rating scales) about patients, after which information was scored, interpreted, and formatted in a report style that was helpful for assessment and treatment of patients with ADHD. Physicians evaluated their practice behaviors quarterly and addressed underperforming areas. RESULTS: Pediatricians in the intervention group, compared with those in the control group, demonstrated significantly higher rates of many American Academy of Pediatrics-recommended ADHD care practices, including collection of parent (Cohen's d = 0.69) and teacher (d = 0.68) rating scales for assessment of children with ADHD, use of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria (d = 0.85), and use of teacher rating scales to monitor treatment responses (d = 1.01). CONCLUSION: A quality improvement intervention that can be widely disseminated by using Internet-based information technology significantly improved the quality of ADHD care in community-based pediatric settings.

Evidence for higher reaction time variability for children with ADHD on a range of cognitive tasks including reward and event rate manipulations.

OBJECTIVE: The purpose of the research study was to examine the manifestation of variability in reaction times (RT) in children with attention deficit hyperactivity disorder (ADHD) and to examine whether RT variability presented differently across a variety of neuropsychological tasks, was present across the two most common ADHD subtypes, and whether it was affected by reward and event rate (ER) manipulations. METHOD: Children with ADHD-combined type (n = 51), ADHD-predominantly inattentive type (n = 53), and 47 controls completed five neuropsychological tasks (Choice Discrimination Task, Child Attentional Network Task, Go/No-Go task, Stop Signal Task, and N-back task), each allowing trial-by-trial assessment of RTs. Multiple indicators of RT variability including RT standard deviation, coefficient of variation and ex-Gaussian tau were used. RESULTS: Children with ADHD demonstrated greater RT variability than controls across all five tasks as measured by the ex-Gaussian indicator tau. There were minimal differences in RT variability across the ADHD subtypes. Children with ADHD also had poorer task accuracy than controls across all tasks except the Choice Discrimination task. Although ER and reward manipulations did affect children's RT variability and task accuracy, these manipulations largely did not differentially affect children with ADHD compared to controls. RT variability and task accuracy were highly correlated across tasks. Removing variance attributable to RT variability from task accuracy did not appreciably affect between-groups differences in task accuracy. CONCLUSIONS: High RT variability is a ubiquitous and robust phenomenon in children with ADHD.

Effects of stimulant medication, incentives, and event rate on reaction time variability in children with ADHD.

This study examined the effects of methylphenidate (MPH) on reaction time (RT) variability in children with attention deficit hyperactivity disorder (ADHD). Using a broad battery of computerized tasks, and both conventional and ex-Gaussian indicators of RT variability, in addition to within-task manipulations of incentive and event rate (ER), this study comprehensively examined the breadth, specificity, and possible moderators of effects of MPH on RT variability. A total of 93 children with ADHD completed a 4-week within-subject, randomized, double-blind, placebo-controlled crossover trial of MPH to identify an optimal dosage. Children were then randomly assigned to receive either their optimal MPH dose or placebo after which they completed five neuropsychological tasks, each allowing trial-by-trial assessment of RTs. Stimulant effects on RT variability were observed on both measures of the total RT distribution (ie, coefficient of variation) as well as on an ex-Gaussian measure examining the exponential portion of the RT distribution (ie, τ). There was minimal, if any, effect of MPH on performance accuracy or RT speed. Within-task incentive and ER manipulations did not appreciably affect stimulant effects across the tasks. The pattern of significant and pervasive effects of MPH on RT variability, and few effects of MPH on accuracy and RT speed suggest that MPH primarily affects RT variability. Given the magnitude and breadth of effects of MPH on RT variability as well as the apparent specificity of these effects of MPH on RT variability indicators, future research should focus on neurophysiological correlates of effects of MPH on RT variability in an effort to better define MPH pharmacodynamics.

Parental Agreement on ADHD Symptom-Specific and Broadband Externalizing Ratings of Child Behavior.

Mothers and fathers often disagree in their ratings of child behavior as evidenced clinically and supported by a substantial literature examining parental agreement on broadband rating scales. The present study examined mother-father agreement on DSM-based, ADHD symptom-specific ratings, as compared to agreement on broadband ratings of externalizing behavior. Using mother and father ratings from 324 children who participated in the Multimodal Treatment Study of Children with ADHD, parental agreement was computed and patterns of disagreement were examined. Mother-father ratings were significantly correlated. However, a clear pattern of higher ratings by mothers compared to fathers was present across ratings. Agreement on ADHD symptom-specific ratings was significantly lower than agreement for broadband externalizing behaviors or ODD symptoms. Of several moderator variables tested, parental stress was the only variable that predicted the discrepancy in ratings. Disagreement between parents is clinically significant and may pose complications to the diagnostic process.