The stability and persistence of symptoms in childhood-onset ADHD.

The course of childhood-onset attention deficit hyperactivity disorder (ADHD) varies across individuals; some will experience persistent symptoms while others' symptoms fluctuate or remit. We describe the longitudinal course of ADHD symptoms and associated clinical characteristics in adolescents with childhood-onset ADHD. Participants (aged 6-12 at baseline) from the Longitudinal Assessment of Manic Symptoms (LAMS) study who met DSM criteria for ADHD prior to age 12 were evaluated annually with the Kiddie Schedule for Affective Disorders and Schizophrenia for eight years. At each timepoint, participants were categorized as meeting ADHD criteria, subthreshold criteria, or not having ADHD. Stability of course was defined by whether participants experienced consistent ADHD symptoms, fluctuating symptoms, or remission. The persistence of the symptoms was defined by symptom status at the final two follow-ups (stable ADHD, stable remission, stable partial remission, unstable). Of 685 baseline participants, 431 had childhood-onset ADHD and at least two follow-ups. Half had a consistent course of ADHD, nearly 40% had a remitting course, and the remaining participants had a fluctuating course. More than half of participants met criteria for ADHD at the end of their participation; about 30% demonstrated stable full remission, 15% had unstable symptoms, and one had stable partial remission. Participants with a persistent course and stable ADHD outcome reported the highest number of symptoms and were most impaired. This work builds on earlier studies that describe fluctuating symptoms in young people with childhood-onset ADHD. Results emphasize the importance of ongoing monitoring and detailed assessment of factors likely to influence course and outcome to help young people with childhood-onset ADHD.

Engagement Barriers to Behavior Therapy for Adolescent ADHD.

OBJECTIVE: To identify barriers to behavior therapy for adolescent ADHD (Supporting Teens' Autonomy Daily; STAND) and understand the relationship between barriers and treatment engagement. METHOD: A mixed-method design with qualitative coding of 822 audio-recorded therapy sessions attended by 121 adolescents with ADHD (ages 11-16; 72.7% male, 77.7% Latinx, 7.4% African-American, 11.6% White, non-Latinx) and parents. Grounded theory methodology identified barriers articulated by parents and adolescents in session. Barriers were sorted by subtype (cognitive/attitudinal, behavioral, logistical) and subject (parent, teen, dyad). Frequency and variety of barriers were calculated by treatment phase (engagement, skills, planning). Generalized linear models and generalized estimating equations examined between-phase differences in frequency of each barrier and relationships between barriers frequency, subtype, subject, and phase on engagement (attendance and homework completion). RESULTS: Coding revealed twenty-five engagement barriers (ten cognitive/attitudinal, eleven behavioral, four logistical). Common barriers were: low adolescent desire (72.5%), parent failure to monitor skill application (69.4%), adolescent forgetfulness (60.3%), and adolescent belief that no change is needed (56.2%). Barriers were most commonly cognitive/attitudinal, teen-related, and occurring in STAND's planning phase. Poorer engagement was associated with cognitive/attitudinal, engagement phase, and dyadic barriers. Higher engagement in treatment was predicted by more frequent behavioral, logistical, parent, and skills/planning phase barriers. CONCLUSIONS: Baseline assessment of barriers may promote individualized engagement strategies for adolescent ADHD treatment. Cognitive/attitudinal barriers should be targeted at treatment outset using evidence-based engagement strategies (e.g., Motivational Interviewing). Behavioral and logistical barriers should be addressed when planning and reviewing application of skills.

Harmonizing Depression Measures Across Studies: a Tutorial for Data Harmonization.

There has been increasing interest in applying integrative data analysis (IDA) to analyze data across multiple studies to increase sample size and statistical power. Measures of a construct are frequently not consistent across studies. This article provides a tutorial on the complex decisions that occur when conducting harmonization of measures for an IDA, including item selection, response coding, and modeling decisions. We analyzed caregivers' self-reported data from the ADHD Teen Integrative Data Analysis Longitudinal (ADHD TIDAL) dataset; data from 621 of 854 caregivers were available. We used moderated nonlinear factor analysis (MNLFA) to harmonize items reflecting depressive symptoms. Items were drawn from the Symptom Checklist 90-Revised, the Patient Health Questionnaire-9, and the World Health Organization Quality of Life questionnaire. Conducting IDA often requires more programming skills (e.g., Mplus), statistical knowledge (e.g., IRT framework), and complex decision-making processes than single-study analyses and meta-analyses. Through this paper, we described how we evaluated item characteristics, determined differences across studies, and created a single harmonized factor score that can be used to analyze data across all four studies. We also presented our questions, challenges, and decision-making processes; for example, we explained the thought process and course of actions when models did not converge. This tutorial provides a resource to support prevention scientists to generate harmonized variables accounting for sample and study differences.

Are There Long-Term Effects of Behavior Therapy for Adolescent ADHD? A Qualitative Study.

We utilized qualitative methodology to characterize potential long-term effects (therapeutic and iatrogenic) of behavior therapy for adolescents with ADHD. Forty-two in-depth interviews were conducted with adolescents with ADHD and parents, 4 years post-treatment. Grounded theory methods identified and reported prevalence of themes. All reported long-term effects were classified as benefits; no iatrogenic effects were noted. Long-term impact themes reported for a majority of participants included: development of organization skills (81.0%), enhanced motivation (57.1%), improved self-awareness (57.1%), improved parental knowledge of ADHD (76.2%), increased parent autonomy granting (61.9%), enhanced parental engagement with the youth (52.4%), and improved parent-teen relationships (52.4%). Fourteen themes were present for smaller subsamples, including reduced need for medication (3 of 9 medicated participants). Experimental studies of behavior therapy for adolescent ADHD should measure themes detected herein and directly test the possibility of long-term treatment effects.

The course of attention-deficit/hyperactivity disorder through midlife.

The course of ADHD from childhood up to young adulthood has been characterized in several studies. However, little is known about the course of symptoms into middle age and beyond. This study aims to evaluate predictors of ADHD trajectories in midlife based on three assessments. The follow-up sample comprised 323 adults with ADHD, evaluated at baseline and seven and thirteen years later, from the average ages of 34 up to 47 years old. ADHD status at reassessments was used to characterize trajectories. Demographics, ADHD features, comorbidities, and polygenic scores for ADHD and genetically correlated psychiatric disorders were evaluated to predict ADHD trajectories. Study retention rate was 67% at T2 (n = 216) and 62% at T3 (n = 199). Data from patients evaluated three times showed that 68.8% coursed stable, 25.5% unstable, and 5.7% remission trajectory of ADHD. Women, individuals with more severe syndromes, higher frequency of comorbidities at reassessments, and genetic liability to depression present a higher probability of a stable trajectory. Our findings shed light on midlife ADHD trajectories and their gender, genomic and clinical correlates.

High Versus Low Intensity Summer Adolescent ADHD Treatment Effects on Internalizing, Social, and Self-Esteem Problems.

The current study aims to evaluate the effectiveness of a high-intensity (HI) versus a low-intensity (LI) skills-based summer intervention delivered to adolescents with ADHD by school staff in improving depressive symptoms, anxiety symptoms, social problems, and self-esteem. Participants were 325 ethnically diverse rising sixth and ninth graders with ADHD randomized to an HI versus an LI intervention (n = 218) or recruited into an untreated comparison group (n = 107). Group x time and group x grade x time one-year outcome trajectories were compared using linear mixed models. Across the transitional year (sixth or ninth grade), adolescents in the HI group were found to experience significantly greater decreases in depressive symptoms (p = .022, d = .25) compared to the LI group. There was no significant impact of the HI intervention (vs. LI) on anxiety symptoms (p = .070, d = .29), social problems (p = .054, d = .34), or self-esteem (p = .837, d = 0.21); however, secondary analyses of the non-randomized untreated comparison group indicated a significant effect of HI versus the untreated comparison group on social problems (p = .009, d = 43). These significant treatment effects suggest that comprehensive academic and organizational skills interventions for adolescents with ADHD may have a secondary impact of relieving adolescent depression for teens with this comorbidity. Given mixed evidence for the efficacy of the HI intervention on social skills, future work should further evaluate this effect.

Four-Year Follow-Up of High versus Low Intensity Summer Treatment for Adolescents with ADHD.

OBJECTIVE: Despite an emergence of psychosocial treatments for adolescent ADHD, their long-term effects are unknown. METHOD: We examine four-year outcomes of a randomized controlled trial (N = 218) comparing high-intensity (HI; 412 h, $4,373 per participant) versus low-intensity (LI; 24 h, $97 per participant) skills-based summer intervention delivered to adolescents with ADHD at two secondary school transitions (6th/9th grade). Quantitative and qualitative analyses evaluated group×time and group×grade×time effects on 4-year outcomes. RESULTS: Relative to LI, a single dose of HI had modest but lasting effects on teen organization skills (d =.40) and ADHD symptoms (9th grade only: d =.27 to.31) at 4-year follow-up. There was no long-term incremental effect of HI (vs. LI) for parent-teen conflict, GPA, or parent use of contingency management. Treatment appeared most effective when delivered to older adolescents (i.e., 9th versus 6th grade), suggesting the long-term impact of ADHD treatment may increase with age. Qualitative data corroborated that the primary long-term benefit of HI (vs. LI) treatment was to organization skills; many of the remaining perceived benefits were to parent and teen psychological variables (i.e., increased self-esteem, self-awareness, parental optimism). HI offered no incremental benefit to long-term educational or clinical service utilization or costs. CONCLUSIONS: Modest therapeutic benefits of adolescent ADHD treatment are maintained long term. However, HI treatment did not impact outcomes that could defray the intervention's high costs ($4,373) compared to LI treatment ($97).

Stakeholder-Generated Implementation Strategies to Promote Evidence-Based ADHD Treatment in Community Mental Health.

Community implementation of evidence-based practices (EBPs) for Attention Deficit/Hyperactivity Disorder (ADHD) is greatly lacking. A recent randomized community-based trial of an EBP for ADHD (Supporting Teens' Autonomy Daily; STAND) demonstrated suboptimal implementation and effectiveness outcomes. In the present study, we conducted an Innovation Tournament (IT) with agency staff stakeholders (N = 26) to identify barriers to successful implementation of STAND and implementation strategies for a revised service delivery model. We conducted member-checking of agency staff-generated ideas with parents (N = 226) and subsequent querying of additional parent (N = 226) and youth-generated (N = 205) strategies to improve care. Go-Zone plots were utilized to identify strategies with the highest feasibility and importance. Practical barriers (i.e., transportation, scheduling difficulties) and parent/youth engagement were the most commonly cited obstacles to successful implementation of STAND in community contexts. Eighteen "winning" implementation strategies were identified that survived member checking. These were classified as train and educate stakeholders (n = 5; e.g., train agency supervisors to deliver supervision, digitize treatment materials and trainings), engage consumers (n = 9; e.g., begin treatment with rapport building sessions, increase psychoeducation), provide interactive assistance (n = 2; e.g., add group supervision, increase roleplay in supervision), and use of evaluative/iterative strategies (n = 2; e.g., perform fidelity checks, supervisor review of session recordings). Parents and youth desired longer duration of treatment and increased focus on maintenance. Strategies will be developed and tested as part of a pilot effectiveness trial designed to refine STAND's service delivery model.Trial Registration NCT02694939 www.clinicaltrials.gov.

Fidelity of Motivational Interviewing in School-Based Intervention and Research.

Educational researchers and school-based practitioners are increasingly infusing motivational interviewing (MI) into new and existing intervention protocols to provide support to students, parents, teachers, and school administrators. To date, however, the majority of the research in this area has focused on feasibility of implementation rather than fidelity of implementation. In this manuscript, we will present MI fidelity data from 245 audio-recorded conversations with 113 unique caregivers and 20 coaches, who implemented a school-based, positive parenting intervention. The aggregate fidelity scores across coaches, parents, and sessions provide evidence the training and support procedures were effective in assisting school-based personnel to implement MI with reasonable levels of fidelity in practice settings. Further, results suggest that MI fidelity varied between sessions and coaches and that within-coach variation (e.g., session-level variation in the quality of MI delivered) greatly exceeded between-coach variation. Implications for practice and future research are discussed.

Implementing Parent-Teen Motivational Interviewing + Behavior Therapy for ADHD in Community Mental Health.

Despite the promise of psychosocial interventions for adolescent Attention Deficit Hyperactivity Disorder (ADHD), there are no studies that examine their implementation in community mental health contexts. In this study, we evaluate the implementation of community-based Supporting Teens' Autonomy Daily (STAND), a parent-teen Motivational Interviewing + Behavior Therapy intervention for adolescents with ADHD. Adolescents with ADHD (N = 225), who were clients at four community mental health agencies, received treatment from 82 therapists. There was double randomization of adolescents and therapists to STAND or Usual Care (UC). Nearly all therapists randomized to STAND completed the training and regularly attended supervision, rating STAND as acceptable and lower burden than UC practices. In the STAND group, MI competence and implementation were lower than in university trials (benchmark range, 19.5% for reflection to question ratio to 83.1% for technical globals). MI integrity in the STAND group was significantly higher than UC across most MITI indices. Content fidelity was adequate in STAND's engagement and skills phases (76.4-85.0%), but not its planning phase (24.4%). Therapists commonly neglected weekly review of goals and home practice and deviated from manualized pace and sequencing of therapy tasks. Learning MI was more challenging for bilingual therapists and therapists with more years of experience. STAND was delivered with higher integrity in earlier sessions and office-based sessions. Discussion identifies future directions for exporting adolescent ADHD interventions to community settings. Patient outcome data for this trial is presented elsewhere. Trial Registration: NCT02694939 www.clinicaltrials.gov .

Presenting problem profiles for adolescents with ADHD: differences by sex, age, race, and family adversity.

BACKGROUND: Adolescents with attention-deficit/hyperactivity disorder (ADHD) experience developmentally distinct challenges from children and adults with ADHD. Yet no work in this age group identifies treatment-related phenotypes that can inform treatment matching, development of tailored treatments, and screening efforts. METHOD: This study uses Latent Profile Analysis to detect unique presenting problem profiles among adolescents with ADHD and to test whether these profiles differ by key individual characteristics (age, sex, race, family adversity level). Participants were 854 ethnically diverse adolescents (ages 10-17) from the ADHD Teen Integrative Data Analysis Longitudinal (TIDAL) dataset who were assessed at clinical referral. Parent, adolescent, and teacher ratings, educational testing, and school records measured eight key presenting problems at intake. RESULTS: A three-profile solution emerged. ADHD simplex (63.7%) was characterized by a mix of the ADHD-Inattentive and ADHD-Combined subtypes, moderate impairment levels, and infrequent comorbidities. ADHD + internalizing (11.4%) was characterized by higher likelihood of comorbid anxiety and/or depression. The disruptive/disorganized ADHD (24.9%) profile was characterized by severe organization, time management, and planning (OTP) problems, the ADHD-Combined subtype, and frequent disruptive behavior at school. Age did not vary across these phenotypes. More females were present in the ADHD + internalizing phenotype; males were more likely to be found in the disruptive/disorganized ADHD phenotype. Higher family adversity and African American race were associated with the disruptive/disorganized ADHD phenotype. CONCLUSIONS: Adolescents with ADHD demonstrate varying presenting problem phenotypes that vary by sex, family adversity, and race/ethnicity. Consideration of these phenotypes may inform treatment matching and efforts to improve screening among under-diagnosed groups.

The ADHD teen integrative data analysis longitudinal (TIDAL) dataset: background, methodology, and aims.

BACKGROUND: The Attention Deficit Hyperactivity Disorder (ADHD) Teen Integrative Data Analysis Longitudinal (TIDAL) dataset integrates data from four randomized trials. METHOD: Participants with ADHD (N = 854; 72.5% male, 92.5% racial/ethnic minority, ages 10-17) were assessed three times across 12 months. Data includes parent, self, and teacher ratings, observations, and school records. The battery was harmonized using an Integrative Data Analysis (IDA) approach to form variables that assign unique values to all participants. RESULTS: The data will be used to investigate: (1) profiles that organize the heterogeneous population into clinically meaningful subgroups, (2) whether these profiles predict treatment response, (3) heterogeneity in treatment response and variables that predict this response, (4) how treatment characteristics and adjunctive supports predict treatment response, and (5) mediators of treatment and whether these mechanisms are moderated by treatment characteristics. CONCLUSIONS: The ADHD TIDAL Dataset will be openly shared with the field to maximize its utility.

Parent-Teen Group versus Dyadic Treatment for Adolescent ADHD: What Works for Whom?

The goal of this study was to evaluate the comparative efficacy of 2 clinic-based psychosocial treatment modalities for adolescent attention deficit/hyperactivity disorder (ADHD) and identify characteristics that facilitate patient-modality matching. Culturally diverse adolescents with ADHD (N = 123) were randomized to 1 of 2 versions of a parent-teen psychosocial treatment for ADHD (Supporting Teens' Autonomy Daily [STAND]): (a) group parent and adolescent skills training or (b) dyadic skills training blended with motivational interviewing. Participants were assessed at baseline, posttreatment, and 6-month follow-up on ADHD symptom severity and functional treatment targets. Differences in therapy process and cost were documented. Modality differences in outcome were examined using linear mixed and general linear models. Each modality successfully engaged the proposed therapy processes. Dyadic and group STAND produced equivalent overall outcomes. However, the dyadic modality demonstrated superior efficacy when parents had elevated ADHD or depression symptoms or high conflict with the teen. Families with lower parent education level and higher parental depression showed lower overall attendance; married parents were more likely to attend dyadic STAND (vs. group). Naturalistic stimulant medication did not influence treatment outcome. At less than one third of the cost of dyadic treatment, group models may be an economical option for treating parents and adolescents with ADHD. Screening adolescents with ADHD for parental psychopathology and parent-teen conflict may allow clinics to match higher risk patients to more personalized approaches that can enhance efficacy.

Metacognitive and motivation deficits, exposure to trauma, and high parental demands characterize adolescents with late-onset ADHD.

The objective of this study is to evaluate support for three hypotheses about the etiology of adolescent-onset ADHD symptoms: (1) a "cool" cognitive load hypothesis, (2) a "hot" rewards processing hypothesis, and (3) a trauma exposure hypothesis. Participants (N = 50) were drawn from two public high schools in a culturally diverse metropolitan area. A detailed procedure for identifying and confirming late-onset ADHD cases is described. Adolescents with late-onset ADHD (n = 15) were identified and compared to childhood-onset (n = 17) and non-ADHD classmates (n = 18). Adolescents and parents completed measures of neurocognition, rewards' processing, clinical profile, and environmental demands. Late-onset cases were clinically and neurocognitively indistinguishable from childhood-onset cases; however, they experienced higher demands from parents (d = 1.09). Compared to the non-ADHD group, late-onset cases showed significant deficits in metacognition (d = 1.25) and academic motivation (d = 0.80), as well as a pronounced history of multiple trauma exposure (OR 11.82). At 1-year follow-up, ADHD persisted in 67.7% of late-onset cases. Late-onset cases (26.7%) were more likely than childhood-onset cases (0.0%) to transfer to alternative schools by 1-year follow-up. Multiple factors may contribute to adolescent-onset ADHD. Adolescents with metacognition and motivation deficits may be at greatest risk for the late-onset ADHD phenotype, particularly in highly demanding environments. Exposure to traumatic stress may play a key role in the exacerbation of existing deficits or onset of new symptoms. Late-onset ADHD was persistent in most cases and associated with higher risk for school disengagement than childhood-onset ADHD. Further work is needed to better understand the etiologies of late-onset ADHD symptoms.

Maternal personality traits moderate treatment response in the Multimodal Treatment Study of attention-deficit/hyperactivity disorder.

Some mothers of children with attention-deficit/hyperactivity disorder (ADHD) present with maladaptive personality profiles (high neuroticism, low conscientiousness). The moderating effect of maternal personality traits on treatment outcomes for childhood ADHD has not been examined. We evaluate whether maternal neuroticism and conscientiousness moderated response in the Multimodal Treatment Study of Children with ADHD. This is one of the first studies of this type. In a randomized controlled trial (RCT), 579 children aged 7-10 (M = 8.5); 19.7% female; 60.8% White with combined-type ADHD were randomly assigned to systematic medication management (MedMgt) alone, comprehensive multicomponent behavioral treatment (Beh), their combination (Comb), or community comparison treatment-as-usual (CC). Latent class analysis and linear mixed effects models included 437 children whose biological mothers completed the NEO Five-Factor Inventory at baseline. A 3-class solution demonstrated best fit for the NEO: MN&MC = moderate neuroticism and conscientiousness (n = 284); HN&LC = high neuroticism, low conscientiousness (n = 83); LN&HC = low neuroticism, high conscientiousness (n = 70). Per parent-reported symptoms, children of mothers with HN&LC, but not LN&HC, had a significantly better response to Beh than to CC; children of mothers with MN&MC and LN&HC, but not HN&LC, responded better to Comb&MedMgt than to Beh&CC. Per teacher-reported symptoms, children of mothers with HN&LC, but not LN&HC, responded significantly better to Comb than to MedMgt. Children of mothers with high neuroticism and low conscientiousness benefited more from behavioral treatments (Beh vs. CC; Comb vs. MedMgt) than other children. Evaluation of maternal personality may aid in treatment selection for children with ADHD, though additional research on this topic is needed.

High versus Low Intensity Summer Treatment for ADHD Delivered at Secondary School Transitions.

Spikes in symptom severity are noted for adolescents with attention deficit/hyperactivity disorder (ADHD) at the transitions to middle and high school that are attributed to developmental maladjustment. This study evaluated the effectiveness of high-intensity (HI; 412 hr, $4,373 per participant) versus low-intensity (LI; 24 hr, $97 per participant) skills-based summer intervention delivered to adolescents with ADHD by local school district staff. Participants were 325 ethnically diverse rising sixth and ninth graders with ADHD randomized to HI versus LI (n = 218) or recruited into an untreated comparison group (n = 107). Group × Time 1-year outcome trajectories were compared using linear mixed models. Both interventions possessed high fidelity and were viewed by families as enjoyable and beneficial. Youth attendance was higher for HI (~80%) versus LI (~45%). Parent training attendance was uniform across groups (~50%). Parent and student attendance did not impact trajectories. Primary benefits of HI over LI were to note taking (d = .50), parent contingency management (d = .43), and parent-rated ADHD symptoms (d = .40-.46; ninth grade only). Secondary analyses suggested that HI may produce additional benefits compared to no treatment for home organization skills (HI vs. untreated d = .54), parent-teen conflict (HI vs. untreated d = .39), and grade point average (HI vs. untreated d = .47, ninth grade only). Summer HI treatment was superior to LI in engagement and uptake of certain skills. However, the extent to which these medium benefits on a limited number of outcomes justify high costs compared to LI remains an open question. Delivering treatment during the summer instead of school year may limit generalizability.

Defining ADHD symptom persistence in adulthood: optimizing sensitivity and specificity.

OBJECTIVE: Longitudinal studies of children diagnosed with ADHD report widely ranging ADHD persistence rates in adulthood (5-75%). This study documents how information source (parent vs. self-report), method (rating scale vs. interview), and symptom threshold (DSM vs. norm-based) influence reported ADHD persistence rates in adulthood. METHOD: Five hundred seventy-nine children were diagnosed with DSM-IV ADHD-Combined Type at baseline (ages 7.0-9.9 years) 289 classmates served as a local normative comparison group (LNCG), 476 and 241 of whom respectively were evaluated in adulthood (Mean Age = 24.7). Parent and self-reports of symptoms and impairment on rating scales and structured interviews were used to investigate ADHD persistence in adulthood. RESULTS: Persistence rates were higher when using parent rather than self-reports, structured interviews rather than rating scales (for self-report but not parent report), and a norm-based (NB) threshold of 4 symptoms rather than DSM criteria. Receiver-Operating Characteristics (ROC) analyses revealed that sensitivity and specificity were optimized by combining parent and self-reports on a rating scale and applying a NB threshold. CONCLUSION: The interview format optimizes young adult self-reporting when parent reports are not available. However, the combination of parent and self-reports from rating scales, using an 'or' rule and a NB threshold optimized the balance between sensitivity and specificity. With this definition, 60% of the ADHD group demonstrated symptom persistence and 41% met both symptom and impairment criteria in adulthood.

Young adult outcomes in the follow-up of the multimodal treatment study of attention-deficit/hyperactivity disorder: symptom persistence, source discrepancy, and height suppression.

BACKGROUND: The Multimodal Treatment Study (MTA) began as a 14-month randomized clinical trial of behavioral and pharmacological treatments of 579 children (7-10 years of age) diagnosed with attention-deficit/hyperactivity disorder (ADHD)-combined type. It transitioned into an observational long-term follow-up of 515 cases consented for continuation and 289 classmates (258 without ADHD) added as a local normative comparison group (LNCG), with assessments 2-16 years after baseline. METHODS: Primary (symptom severity) and secondary (adult height) outcomes in adulthood were specified. Treatment was monitored to age 18, and naturalistic subgroups were formed based on three patterns of long-term use of stimulant medication (Consistent, Inconsistent, and Negligible). For the follow-up, hypothesis-generating analyses were performed on outcomes in early adulthood (at 25 years of age). Planned comparisons were used to estimate ADHD-LNCG differences reflecting persistence of symptoms and naturalistic subgroup differences reflecting benefit (symptom reduction) and cost (height suppression) associated with extended use of medication. RESULTS: For ratings of symptom severity, the ADHD-LNCG comparison was statistically significant for the parent/self-report average (0.51 ± 0.04, p < .0001, d = 1.11), documenting symptom persistence, and for the parent/self-report difference (0.21 ± 0.04, p < .0001, d = .60), documenting source discrepancy, but the comparisons of naturalistic subgroups reflecting medication effects were not significant. For adult height, the ADHD group was 1.29 ± 0.55 cm shorter than the LNCG (p < .01, d = .21), and the comparisons of the naturalistic subgroups were significant: the treated group with the Consistent or Inconsistent pattern was 2.55 ± 0.73 cm shorter than the subgroup with the Negligible pattern (p < .0005, d = .42), and within the treated group, the subgroup with the Consistent pattern was 2.36 ± 1.13 cm shorter than the subgroup with the Inconsistent pattern (p < .04, d = .38). CONCLUSIONS: In the MTA follow-up into adulthood, the ADHD group showed symptom persistence compared to local norms from the LNCG. Within naturalistic subgroups of ADHD cases, extended use of medication was associated with suppression of adult height but not with reduction of symptom severity.

Late-Onset ADHD: Understanding the Evidence and Building Theoretical Frameworks.

PURPOSE OF REVIEW: The traditional definition of Attention-Deficit/Hyperactivity Disorder (ADHD), assuming onset in childhood, has been challenged by evidence from four recent birth-cohort studies that reported most adults with ADHD lacked a childhood categorical ADHD diagnosis. RECENT FINDINGS: Late onset of symptoms was evaluated in the long-term follow-up of the Multimodal Treatment study of ADHD (MTA). In most cases, other factors were present that discounted the late onset of ADHD symptoms and excluded the diagnosis of ADHD. We offer two theoretical frameworks for understanding the ADHD trajectory throughout the life cycle: (1) the complex phenotype model, and (2) the restricted phenotype model. We conclude that (a) late onset (after age 12) is a valid trajectory for ADHD symptoms, (b) the percentage of these cases with onset after adolescence is yet uncertain, and