The clinical relevance of subgroups of autistic adults: Stability and predictive value.

Autism in adulthood is characterized by heterogeneity, complicating the provision of tailored support. In previous work, we aimed to capture this heterogeneity by determining subgroups of autistic adults that differed in clinical outcomes: cognitive failures, psychological difficulties, and quality of life (QoL). Two subgroups were identified: a "Feelings of Low Grip" subgroup characterized by experiencing a lower sense of mastery and a higher susceptibility to difficulties in daily life, and a "Feelings of High Grip" subgroup characterized by a higher sense of mastery and lower susceptibility to difficulties in daily life. The current pre-registered study involves a longitudinal extension to determine (a) stability and (b) predictive value of the previously identified two subgroups. Subgroups were identified using community detection based on 14 self-report measures related to demographic, psychological, and lifestyle characteristics in two samples (aged 31-86 years) that were analyzed separately: Sample 1 (NAutism = 80) measured 5 years after baseline and Sample 2 (NAutism = 241, NComparison = 211) measured 2 years after baseline. The stability over time was assessed based on (a) the number of subgroups, (b) subgroup profiles, and (c) subgroup membership. Predictive validity was assessed for cognitive failures, psychological difficulties, and QoL. Results indicated that autistic and non-autistic adults formed distinct subgroups. Within both autism samples, the two previously identified autism subgroups were replicated at follow-up. Subgroup profiles were similar for >50% of the variables at two-year follow-up, and 21% at five-year follow-up. Moreover, ≥76% remained in the same subgroup at two-year follow-up, and ≥ 57% after 5 years. Subgroup membership was predictive of external clinical outcomes up to 5 years. Thus, this study demonstrated the stability and predictive value of the autism subgroups, especially for the two-year follow-up. A further focus on their clinical utility might increase the aptness of support, and may provide more insight into the aging process when being autistic.

The short- and longer-term effects of brief behavioral parent training versus care as usual in children with behavioral difficulties: study protocol for a randomized controlled trial.

BACKGROUND: The access to and uptake of evidence-based behavioral parent training for children with behavioral difficulties (i.e., oppositional, defiant, aggressive, hyperactive, impulsive, and inattentive behavior) are currently limited because of a scarcity of certified therapists and long waiting lists. These problems are in part due to the long and sometimes perceived as rigid nature of most evidence-based programs and result in few families starting behavioral parent training and high dropout rates. Brief and individually tailored parenting interventions may reduce these problems and make behavioral parent training more accessible. This protocol paper describes a two-arm, multi-center, randomized controlled trial on the short- and longer-term effectiveness and cost-effectiveness of a brief, individually tailored behavioral parent training program for children with behavioral difficulties. METHODS: Parents of children aged 2-12 years referred to a child mental healthcare center are randomized to (i) three sessions of behavioral parent training with optional booster sessions or (ii) care as usual. To evaluate effectiveness, our primary outcome is the mean severity of five daily ratings by parents of four selected behavioral difficulties. Secondary outcomes include measures of parent and child behavior, well-being, and parent-child interaction. We explore whether child and parent characteristics moderate intervention effects. To evaluate cost-effectiveness, the use and costs of mental healthcare and utilities are measured. Finally, parents' and therapists' satisfaction with the brief program are explored. Measurements take place at baseline (T0), one week after the brief parent training, or eight weeks after baseline (in case of care as usual) (T1), and six months (T2) and twelve months (T3) after T1. DISCUSSION: The results of this trial could have meaningful societal implications for children with behavioral difficulties and their parents. If we find the brief behavioral parent training to be more (cost-)effective than care as usual, it could be used in clinical practice to make parent training more accessible. TRIAL REGISTRATION: The trial is prospectively registered at ClinicalTrials.gov (NCT05591820) on October 24th, 2022 and updated throughout the trial.

When mind and measurement diverge; the interplay between subjective cognitive complaints (SCCs), objective cognition, age, and depression in autistic adults.

While the increased incidence of dementia and subjective cognitive complaints (SCCs) suggests that autistic adults may face cognitive challenges at older age, the extent to which SCCs predict (future) cognitive functioning remains uncertain. This uncertainty is complicated by associations with variables like depression. The current study aims to unravel the interplay of age, depression, cognitive performance, and SCCs in autism. Using a large cross-sectional cohort of autistic (n=202) and non-autistic adults (n=247), we analyzed associations of SCCs with age, depression, and cognitive performance across three domains (visual memory, verbal memory, and fluency). Results showed a strong significant association between depression and SCCs in both autistic and non-autistic adults. Cognitive performance was not significantly associated with SCCs, except for a (modest) association between visual memory performance and SCCs in autistic adults only. Follow-up regression tree analysis indicated that depression and being autistic were considerably more predictive of SCCs than objective cognitive performance. Age nor sex was significantly associated with SCCs. These findings indicate that self-reported cognitive functioning does not equal cognitive performance, and should be interpreted with care, especially in individuals with high rates of depression. Longitudinal investigations are needed to understand SCCs' role in dementia and cognitive health in autism.

Effectiveness, working mechanisms, and implementation of youth-initiated mentoring for juvenile delinquents: a multiple-methods study protocol.

BACKGROUND: The societal costs associated with juvenile delinquency and reoffending are high, emphasising the need for effective prevention strategies. A promising approach is Youth-Initiated Mentoring (YIM). In YIM, professionals support youths in selecting a non-parental adult from within their social network as their mentor. However, until now, little (quasi-)experimental research has been conducted on YIM in the field of juvenile delinquency. We will examine the effectiveness, working mechanisms, and implementation of YIM as a selective prevention strategy for juvenile delinquents. METHODS: This multiple-methods study consists of a quasi-experimental trial and a qualitative study. In the quasi-experimental trial, we aim to include 300 juvenile offenders referred to Halt, a Dutch juvenile justice system organisation which offers youths a diversion program. In the Netherlands, all juvenile offenders between 12 and 18 years old are referred to Halt, where they must complete the Halt intervention. Youths will be non-randomly assigned to region-matched non-YIM-trained and YIM-trained Halt professionals implementing Care as Usual (CAU, i.e., the Halt intervention) or CAU plus YIM, respectively. Despite non-random allocation, this approach may yield comparable conditions regarding (1) the characteristics of professionals delivering the intervention and (2) case type and severity. Youth and caregiver(s) self-report data will be collected at pre-and post-test and a 6-month follow-up and complemented with official Halt records data. Multilevel analyses will test whether youths following CAU plus YIM show a stronger increase in resilience factors and a stronger decline in the need for formal support and delinquency than youths following CAU. In the qualitative study, we will organise focus group interviews with YIM-trained professionals to explore boosters and barriers experienced by professionals during the implementation of YIM. DISCUSSION: The proposed study will help identify the effectiveness of YIM in strengthening resilience factors and possibly decreasing juvenile delinquency. In addition, it may offer insights into how and for whom YIM works. Finally, this study can help strengthen the implementation of YIM in the future. TRIAL REGISTRATION: ClinicalTrials.Gov (# NCT05555472). Registered 7 September 2022. https://www. CLINICALTRIALS: gov/ct2/show/NCT05555472?cond=Youth+Initiated+Mentoring&draw=2&rank=1 .

Navigating adolescence: pubertal development in autism spectrum conditions and its relation to mental health.

Adolescence is a period of social, psychological, and physiological change, including the onset of puberty. Differential pubertal onset has been linked to a myriad of problems, including mental health problems. Therefore, we aim to investigate deviating pubertal development in autism, and whether this is more pronounced in girls than in boys. A total of 68 individuals (nASC = 34, nCOM (comparisons) = 34) aged 12 to 16 years were administered test concerning pubertal development and mental health (i.e., sensory sensitivity, autistic traits, depression, anxiety, and externalizing problems). Frequentist and Bayesian ANOVA was used to examine deviations in pubertal development in ASC and possible sex effects. Regression analyses was used to test whether this asynchronicity was linked to mental health problems. Our (frequentist and Bayesian) analyses revealed earlier onset and slower development of pubertal development in ASC but we did not find any sex differences. Maturation disparity was linked to higher mental health problems in ASC, but not in COM. No sex differences in the relation with mental health outcomes was found. We found evidence for a slower development of "true" puberty in those with ASC compared to those without. Moreover, we show that disparities in pubertal development are related to mental health in ASC, suggesting a greater impact on mental health in autistic than in non-autistic teens. Longitudinal studies are necessary to elucidate important developmental trajectories in puberty in neurodiverse populations.

Remembering the future; prospective memory across the autistic adult's life span.

LAY ABSTRACT: What is already known: Prospective memory is an important function for daily living. It is the cognitive function that helps you remember that you are meeting your friend for coffee at 2 pm tomorrow, or that you need to take your vitamins after breakfast. This cognitive function is particularly important in autistic adults, but how prospective memory is associated with increasing age, we currently do not know.What this paper adds: Although performance on experimental tasks that measure prospective memory decreases with age, this pattern is similar in autistic and non-autistic adults. No age effects were found for tasks that were performed outside the lab. Autistic adults and non-autistic adults perform similarly on prospective memory, and this performance remains similar when autistic and non-autistic adults age.Implications for practice, research, or policy: While our results show that prospective memory decreased with increasing age, our results do point to parallel development of prospective memory in autistic and non-autistic adults. This finding serves as a reassurance for those individuals concerned that older autistic individuals might show quicker cognitive decline.

The relationship between camouflaging and mental health: Are there differences among subgroups in autistic adults?

LAY ABSTRACT: When autistic people use strategies to hide their autistic characteristics, we call this camouflaging. Autistic adults suggested that camouflaging can result in mental health difficulties. That is, people who report to camouflage also report mental health difficulties. However, since there are many differences between autistic people, this relationship may also differ between subgroups. Therefore, in this study we investigated whether camouflaging and mental health difficulties are related and whether this relationship is equal for all autistic adults. For this study, 352 autistic adults aged 30-84 years filled in the Dutch Camouflaging Autistic Traits Questionnaire to measure camouflaging and the Symptom Checklist-90 Revised to measure mental health difficulties. We found that camouflaging was moderately related to mental health difficulties. This means that people who report more camouflaging also report more mental health difficulties. When we looked closer, we found that this relationship was strong for only a small subgroup of autistic adults. In most other autistic adults, there was a small or no relationship between camouflaging and mental health difficulties. Therefore, it is important that clinicians are aware of camouflaging and its possible relationship with mental health difficulties, but that they do not generalize the negative consequences to everyone.

Comparison of network structures between autistic and non-autistic adults, and autism subgroups: A focus on demographic, psychological, and lifestyle factors.

LAY ABSTRACT: There are large differences in the level of demographic, psychological, and lifestyle characteristics between autistic and non-autistic adults but also among autistic people. Our goal was to test whether these differences correspond to differences in underlying relationships between these characteristics-also referred to as network structure-to determine which characteristics (and relationships between them) are important. We tested differences in network structure in (1) autistic and non-autistic adults and (2) two previously identified subgroups of autistic adults. We showed that comparing networks of autistic and non-autistic adults provides subtle differences, whereas networks of the autism subgroups were similar. There were also no sex differences in the networks of the autism subgroups. Thus, the previously observed differences in the level of characteristics did not correspond to differences across subgroups in how these characteristics relate to one another (i.e. network structure). Consequently, a focus on differences in characteristics is not sufficient to determine which characteristics (and relationships between them) are of importance. Hence, network analysis provides a valuable tool beyond looking at (sub)group level differences. These results could provide hints for clinical practice, to eventually determine whether psychological distress, cognitive failures, and reduced quality of life in autistic adults can be addressed by tailored support. However, it is important that these results are first replicated before we move toward intervention or support.

Sustained improvements by behavioural parent training for children with attention-deficit/hyperactivity disorder: A meta-analytic review of longer-term child and parental outcomes.

Background: Behavioural parent training is an evidence-based intervention for children with attention-deficit/hyperactivity disorder (ADHD), but little is known about the extent to which initial benefits are maintained. Aims: This meta-analytic review investigated longer-term (i.e., more than 2 months post-intervention) child and parental outcomes of behavioural parent training for children with ADHD. Materials & Methods: We searched for randomized controlled trials and examined ADHD symptoms, behavioural problems, positive parenting, negative parenting, parenting sense of competence, parent-child relationship quality, and parental mental health as outcomes. We included 27 studies (31 interventions; 217 effect sizes), used multilevel random-effects meta-analyses for between- and within-group comparisons (pre-intervention to follow-up and post-intervention to follow-up), and explored twelve predictors of change. Results: Between pre-intervention and follow-up (M = 5.3 months), we found significant small-to-moderate between-group effects of the intervention on ADHD symptoms, behavioural problems, positive parenting, parenting sense of competence and parent-child relationship quality. Within-group findings show sustained improvements in the intervention conditions for all outcome domains. There were few significant changes from post-intervention to follow-up. Additionally, the large majority of the individual effect sizes indicated sustained outcomes from post-intervention to follow-up. There were seven significant predictors of change in child outcomes, including stronger reductions in ADHD symptoms of girls and behaviour problems of younger children. In contrast with some meta-analyses on short-term effects, we found no differences between masked and unmasked outcomes on ADHD symptoms at follow-up. Discussion & Conclusion: We conclude that behavioural parent training has longer-term benefits for children's ADHD symptoms and behavioural problems, and for positive parenting behaviours, parenting sense of competence and quality of the parent-child relationship.

Prepotent response inhibition in autism: Not an inhibitory deficit?

Research outcomes on prepotent response inhibition in neurodevelopmental conditions during adulthood seem inconsistent, especially in autism. To gain further insight in these inconsistencies, the current study investigates inhibitory performance, as well as task strategies such as adaptive behavior during inhibitory tasks in autistic adults. As Attention-Deficit/Hyperactivity Disorder (ADHD) is often co-occurring in autism and associated with differences in both inhibition and adaptation, the role of ADHD symptoms is explored. Additionally, prior research is extended to middle- and late-adulthood, and the role of cognitive aging is assessed. Hundred-and-five autistic adults and 139 non-autistic adults (age: 20-80 yrs) were compared on a Go-NoGo task. No significant group differences in inhibitory difficulties (commission errors) or adaptation (post error slowing) were observed, and both did not relate significantly to ADHD symptoms. However, when controlling for reaction time autistic individuals made significantly more inhibitory errors than non-autistic individuals, yet the effect size was modest (Cohen's d = .27). Exploratory analyses showed that adaption significantly related to inhibition in non-autistic individuals only, possibly hinting at altered adaptive behavior during inhibitory tasks in autistic adults. ADHD symptoms related to response variability in the autism group only. Furthermore, task strategy changed with older age in both groups, with slower and more cautious responses at older age. Taken together, although minor differences may exist, autistic and non-autistic people show largely similar patterns of inhibitory behavior throughout adulthood. Differences in task timing and strategy seem relevant for future longitudinal studies on cognitive aging across neurodevelopmental conditions.

Finding Similarities in Differences Between Autistic Adults: Two Replicated Subgroups.

Autism is heterogeneous, which complicates providing tailored support and future prospects. We aim to identify subgroups in autistic adults with average to high intelligence, to clarify if certain subgroups might need support. We included 14 questionnaire variables related to aging and/or autism (e.g., demographic, psychological, and lifestyle). Community detection analysis was used for subgroup identification in an original sample of 114 autistic adults with an adulthood diagnosis (autism) and 58 non-autistic adults as comparison group (COMP), and a replication sample (NAutism = 261; NCOMP = 287), both aged 30-89 years. Next, we identified subgroups and assessed external validity (for cognitive and psychological difficulties, and quality of life [QoL]) in the autism samples. To test specificity, we repeated the analysis after adding 123 adults with ADHD, aged 30-80 years. As expected, the autism and COMP groups formed distinct subgroups. Among autistic adults, we identified three subgroups of which two were replicated. One of these subgroups seemed most vulnerable on the cluster variables; this subgroup also reported the most cognitive and psychological difficulties, and lowest QoL. Adding the ADHD group did not alter results. Within autistic adults, one subgroup could especially benefit from support and specialized care, although this must be tested in future studies.

Review: Which components of behavioral parent and teacher training work for children with ADHD? - a metaregression analysis on child behavioral outcomes.

BACKGROUND: This metaregression analysis examined which behavioral techniques that are commonly used in behavioral parent and teacher training programs for children with attention-deficit/hyperactivity disorder (ADHD) were related to program effectiveness on children's behavioral outcomes. METHODS: We included 32 randomized controlled trials (N = 2594 children) investigating behavioral parent training, teacher training, or a combination, in children with ADHD under 18 years. Outcomes were symptom counts of total ADHD, inattention, and hyperactivity-impulsivity and behavioral problems. The dosage of techniques was extracted from the intervention manuals. Metaregression was used to assess which techniques and intervention characteristics (setting, delivery method, duration, and home-school collaboration) were associated with intervention effectiveness. RESULTS: Higher dosage of psycho-education for parents was associated with smaller effects on behavioral problems and, only in case of parent training, also with smaller effects on ADHD symptoms. Higher dosage of teaching parents/teachers to use negative consequences was associated with larger effects on behavioral problems. Individual training compared with group training was associated with larger effects on ADHD and hyperactivity-impulsivity symptoms. CONCLUSIONS: This study provides first insights into the specific techniques that are essential in behavioral parent and teacher training programs for children with ADHD. This knowledge can eventually be used to improve and tailor interventions.

Commentary: Why treatment is the best choice for childhood mental disorders - a commentary on Roest et al. (2022).

An important question in mental healthcare for children is whether treatments are effective and safe in the long run. Here, we comment on a recent editorial perspective by Roest et al. (2022), who argue, based on an overview of systematic reviews, 'that there is no convincing evidence that interventions for the most common childhood disorders are beneficial in the long term'. We believe that the available evidence does not justify this conclusion and express our concern regarding the harmful effects of their message. We show that there is evidence to suggest beneficial longer term treatment effects for each of the disorders and explain why evidence-based treatment should be offered to children with mental disorders.

One size does not fit all: An individualized approach to understand heterogeneous cognitive performance in autistic adults.

Cognitive performances of autistic people vary widely. Therefore, previous group-based comparisons on cognitive aging in autistic adults might have overlooked those autistic adults that are particularly vulnerable for cognitive decline. Multivariate normative comparisons (MNC) statistically assess individual cognitive differences on the entire cognitive profile. Cognitive deviancy as indicated by MNC accurately predicts future cognitive decline, and is therefore sensitive in detecting meaningful cognitive differences. The current study aimed to (1) investigate the applicability of MNC to assess cognitive performance in autism individually, and (2) understand heterogeneous cognitive performance in autistic adults. As pre-registered, we performed MNC in a sample of 254 non-autistic adults, and two independent samples of respectively 118, and 86 autistic adults (20-85 years, mean: 50 years). Cognitive performance was measured on 11 outcomes in six domains (verbal/visual memory, working memory, verbal fluency, Theory of Mind, and psychomotor speed). Using MNC, about twice as many autistic individuals had a deviant cognitive profile (i.e., deviated statistically from the multivariate normspace) as compared to non-autistic individuals. Importantly, most autistic individuals (>80%) did not have a deviant cognitive profile. Having a deviant profile was significantly associated with higher levels of psychological distress in autistic adults specifically, showing the clinical relevance of this method. Therefore, MNC seem a useful tool to individually detect meaningful cognitive differences in autism. These results are consistent with previous cognitive studies suggesting that most autistic adults show fairly similar cognitive profiles to non-autistic adults, yet highlight the necessity for approaches reflecting the heterogeneity observed in autistic people.

Subjective cognition in adults with common psychiatric classifications; a systematic review.

The aim is to assess whether instruments developed to measure subjective cognitive complaints (SCCs) and in neurology and aging can reliably be used in ADHD and other common psychiatric classifications. MEDLINE, PsycINFO, CINAHL and EMBASE+EMBASE CLASSIC were searched for relevant work on SCCs in psychiatric classifications (ADHD, autism, mood disorders, schizophrenia) in two phases: 1 identify instruments, 2 relevant studies. 35 studies with varying study quality were included. SCCs are most commonly studied in ADHD and mood disorders, but are found in all psychiatric classifications. SCCs show inconsistent and low associations to objective cognition across disorders, but higher and consistent relations are found with behavioral outcomes. SCCs are not qualitatively different for ADHD compared to other psychiatric classifications, and should thus not be seen as analogous to well validated measures of objective cognition. However, SCCs do reflect suffering, behavioral difficulties and problems experienced by across those with psychiatric problems in daily life.

Meta-analysis: Which Components of Parent Training Work for Children With Attention-Deficit/Hyperactivity Disorder?

OBJECTIVE: Behavioral parent training is an evidence-based intervention for children with attention-deficit/hyperactivity disorder (ADHD), but it is unknown which of its components are most effective. This meta-regression analysis investigated which specific behavioral techniques that parents learn in parent training are associated with effects on parental outcomes. METHOD: A search was performed for randomized controlled trials on parent training for children with ADHD, with positive parenting, negative parenting, parenting sense of competence, parent-child relationship quality, and parental mental health as outcome measures. After screening 23,026 publications, 29 studies contributing 138 effect sizes were included (N = 2,345). For each study, the dosage of 39 behavioral techniques was derived from intervention manuals, and meta-regression determined which techniques were related to outcomes. RESULTS: Parent training had robust small- to medium-sized positive effects on all parental outcomes relative to control conditions, both for unblinded and probably blinded measures. A higher dosage of techniques focusing on the manipulation of antecedents of behavior was associated with better outcomes on parenting sense of competence and parental mental health, and a higher dosage of techniques focusing on reinforcement of desired behaviors was related to larger decreases in negative parenting. Higher dosages of psychoeducation were negatively related to parental outcomes. CONCLUSION: Although techniques were not investigated in isolation, the results suggested that manipulation of antecedents of behavior and reinforcement techniques are key components of parent training for children with ADHD in relation to parental outcomes. These exploratory findings may help to strengthen and tailor parent training interventions for children with ADHD.

Parallel age-related cognitive effects in autism: A cross-sectional replication study.

Findings on age-related cognitive effects in autism in adulthood are inconsistent across studies. As these studies substantially differ in their methodology, replication studies are needed. In this replication study frequentist (i.e., null-hypothesis significance testing), and Bayesian statistics were used to investigate the hypothesis that in autistic adults compared to non-autistic adults mostly parallel, but also protective age-related cognitive effects can be observed. Participants were 88 autistic adults, and 88 non-autistic matched comparisons (age range: 30-89 years, mean age: 55 years). Cognitive measures were administered on the following six domains: verbal memory, visual memory, working memory, Theory of Mind (ToM), verbal fluency, and processing speed, and self-reported cognitive failures. Non-autistic adults outperformed autistic adults on ToM, verbal fluency, and verbal memory, but only the first two were confirmed with Bayesian replication analyses. Also, more cognitive failures were reported by autistic adults. No interactions between group and age were observed, suggesting a parallel age-related effect on all cognitive domains. In sum, previously observed difficulties in ToM and verbal fluency were replicated which seem to persist at older age. Previously reported parallel age-related cognitive patterns were replicated, yet no evidence for protective age-related patterns was found. LAY SUMMARY: We investigated whether our previous findings on cognitive aging in autism could be confirmed in a new study measuring the cognitive effects of age in autistic and non-autistic adults. As expected, tasks that younger autistic adults had difficulties with (theory of mind, fluency) were also difficult for older autistic adults, and the effect of age itself was similar in autistic and non-autistic adults. Unexpectedly, we observed no protective effects (less cognitive aging) in autism.

Which factors determine clinicians' policy and attitudes towards medication and parent training for children with Attention-Deficit/Hyperactivity Disorder?

Behavioral parent and teacher training and stimulant medication are recommended interventions for children with attention-deficit/hyperactivity disorder (ADHD). However, not all children with ADHD receive this evidence-based care, and the aim of the current study was to find out why. More specifically, we investigated clinicians' policy, guideline use, and attitudes towards medication and parent training when treating children with ADHD, as well as several factors that could affect this. A total of 219 Dutch clinicians (mainly psychologists, psychiatrists and educationalists) completed a survey. Clinicians were likely to recommend medication more often than parent training, and clinicians' policy to recommend medication and parent training was positively associated with their attitudes towards these interventions. Less experienced clinicians and those with a non-medical background reported lower rates of guideline use, whereas clinicians with a medical background reported less positive attitudes towards parent training. Furthermore, a substantial portion of the clinicians based their decision to recommend parent training on their clinical judgement (e.g., prior estimations of efficacy, perceived low abilities/motivation of parents), and many clinicians reported barriers for referral to parent training, such as waiting lists or a lack of skilled staff. To achieve better implementation of evidence-based care for children with ADHD, guidelines should be communicated better towards clinicians. Researchers and policy-makers should further focus on barriers that prevent implementation of parent training, which are suggested by the discrepancy between clinicians' overall positive attitude towards parent training and the relatively low extent to which clinicians actually advise parent training.

An Individual Participant Data Meta-analysis: Behavioral Treatments for Children and Adolescents With Attention-Deficit/Hyperactivity Disorder.

OBJECTIVE: Behavioral interventions are well established treatments for children with attention-deficit/hyperactivity disorder (ADHD). However, insight into moderators of treatment outcome is limited. METHOD: We conducted an individual participant data meta-analysis (IPDMA), including data of randomized controlled behavioral intervention trials for individuals with ADHD <18 years of age. Outcomes were symptoms of ADHD, oppositional defiant disorder (ODD), and conduct disorder (CD) and impairment. Moderators investigated were symptoms and impairment severity, medication use, age, IQ, sex, socioeconomic status, and single parenthood. RESULTS: For raters most proximal to treatment, small- to medium-sized effects of behavioral interventions were found for symptoms of ADHD, inattention, hyperactivity/impulsivity (HI), ODD and CD, and impairment. Blinded outcomes were available only for small preschool subsamples and limited measures. CD symptoms and/or diagnosis moderated outcome on ADHD, HI, ODD, and CD symptoms. Single parenthood moderated ODD outcome, and ADHD severity moderated impairment outcome. Higher baseline CD or ADHD symptoms, a CD diagnosis, and single parenthood were related to worsening of symptoms in the untreated but not in the treated group, indicating a protective rather than an ameliorative effect of behavioral interventions for these children. CONCLUSION: Behavioral treatments are effective for reducing ADHD symptoms, behavioral problems, and impairment as reported by raters most proximal to treatment. Those who have severe CD or ADHD symptoms, a CD diagnosis, or are single parents should be prioritized for treatment, as they may evidence worsening of symptoms in the absence of intervention.