The PANDAS subgroup: recognition and treatment

A subgroup of patients with childhood-onset obsessive-compulsive disorder (OCD) has been identified who share a common clinical course characterized by dramatic symptom exacerbations following Group A beta-hemolytic streptococcal (GABHS) infections. The term PANDAS has been applied to the subgroup, to indicate the postulated etiology of their symptoms: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections. Five clinical characteristics define the PANDAS subgroup: presence of OCD and/or tic disorder, prepubertal symptom onset, sudden onset or abrupt exacerbations (sawtooth course), association with neurological abnormalities (presence of adventitious movements or motoric hyperactivity during exacerbations), and temporal association between symptom exacerbations and GABHS infections. Post-streptococcal symptom exacerbations are typically quite dramatic, with patients reporting that their symptoms "...came on overnight" or "...appeared all of a sudden a few days after I had a sore throat." The post-streptococcal inflammatory nature of the neuropsychiatric symptoms provides novel opportunities for treatment and prevention, including immunomodulatory therapies such as therapeutic plasma exchange (TPE) and intravenous immunoglobulin (IVIG). A recently completed placebo-controlled trial revealed that both IVIG and TPE were effective in reducing neuropsychiatric symptom severity (40% to 55% reductions, respectively) for a group of severely ill children with OCD and/or tic disorders. Further research is required to determine why the treatments are helpful, as well as to ascertain whether or not antibiotic prophylaxis can help prevent post-streptococcal symptom exacerbations.     

Family Impact of Tourette's Syndrome

Tourette's syndrome (TS) is a neuropsychological disorder characterized by vocal and motor tics. TS is also associated with several behavior disorders such as Attention Deficit Hyperactivity Disorder, Oppositional Defiant Disorder, conduct disorder, and Obsessive-Compulsive Disorder. We examined the impact of Tourette's syndrome with and without comorbid psychiatric disorders on the family. TS complicated by comorbid disorders had a greater impact on the family than uncomplicated TS. Tourette's symptom severity was significantly correlated with the level of impact on the family and with the number of comorbid disorders. TS is a disorder with effects that extend beyond motor and vocal tics.     

Motor excitability is reduced prior to voluntary movements in children and adolescents with Tourette syndrome

Tourette syndrome (TS) is a neuro‐developmental disorder characterized by the occurrence of motor and vocal tics: involuntary, repetitive, stereotyped behaviours that occur with a limited duration, often typically many times in a single day. Previous studies suggest that children and adolescents with TS may undergo compensatory, neuroplastic changes in brain structure and function that help them gain control over their tics. In the current study we used single‐pulse and dual‐site paired‐pulse transcranial magnetic stimulation (TMS), in conjunction with a manual choice reaction time task that induces high levels of inter‐manual conflict, to investigate this conjecture in a group of children and adolescents with TS, but without co‐morbid Attention Deficit Hyperactivity Disorder (ADHD). We found that performance on the behavioural response‐conflict task did not differ between the adolescents with TS and a group of age‐matched typically developing individuals. By contrast, our study demonstrated that cortical excitability, as measured by TMS‐induced motor‐evoked potentials (MEPs), was significantly reduced in the TS group in the period immediately preceding a finger movement. This effect is interpreted as consistent with previous suggestions that the cortical hyper‐excitability that may give rise to tics in TS is actively suppressed by cognitive control mechanisms. Finally, we found no reliable evidence for altered patterns of functional inter‐hemispheric connectivity in TS. These results provide evidence for compensatory brain reorganization that may underlie the increased self‐regulation mechanisms that have been hypothesized to bring about the control of tics during adolescence.     

Obsessive-compulsive disorder with and without tic disorder: a comparative study from India

Introduction: Evidence from phenomenological, family, genetic, and treatment studies from Western centers have suggested that tic-related obsessive-compulsive disorder (OCD) could be different from non-tic-related OCD. This study from India investigated the differences in OCD with and without tics, with respect to sociodemographics, symptom profile, and comorbidity, including obsessive-compulsive spectrum disorders, to examine whether the clinical profile of tic-related OCD is similar to that reported previously. Methods: Fifty subjects with OCD and tics (chronic motor tics and Tourette syndrome) were compared with 141 OCD subjects without tics. Results: Subjects having OCD with tics tended to be males, and had an earlier onset of illness. They had more of symmetry/aggressive and religious obsessions, and cleaning, ordering/arranging, hoarding, and repeating compulsions and were associated with trichotillomania and hypochondraisis. Stepwise backward (Wald) regression analysis showed that an early age of onset, male gender, aggressive obsessions, cleaning compulsions, and trichotillomania were significantly associated with tic-related OCD. Conclusion: The findings of this study from India are broadly similar to those reported previously from the West indicating the universality of differences in tic- and non-tic-related OCD. Our findings also support the existing evidence that tics contribute to the heterogeneity of OCD.     

Do obsessional beliefs discriminate OCD without tic patients from OCD with tic and Tourette's syndrome patients?

There is considerable overlap in symptomatology between Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD). Increased rates of tics are found in OCD and up to 60% obsessive-compulsive symptoms in TS. However, in OCD obsessive-compulsive symptoms are more often anxiety-related and, as a consequence, aimed at anxiety-reduction, whereas in TS these symptoms are more stimulus-bound. Therefore, it is of clinical interest to study whether these phenomenological differences are reflected in differences between dysfunctional cognitions accompanying OC symptoms in OCD with or without tics and TS. Current cognitive theory of OCD ascertains that specific dysfunctional beliefs are important in the etiology and maintenance of OCD. To assess these beliefs, the obsessive-compulsive beliefs questionnaire-87 (OBQ-87) has been developed. In the present study, OBQ-87 scores of OCD patients without tics, OCD with tics, and TS (without OCD) patients were compared to those of normal controls. Results: OCD without tic patients exhibited higher OBQ-87 scores than TS patients. No differences were found between OCD with or without tic patients on any of the OBQ-87 subscales. These results suggest that: (1) dysfunctional beliefs have no discriminative power with respect to OCD with or without tic patients; (2) the direct relationship between types of OC symptoms and specific dysfunctional beliefs is questionable. Therefore, one can doubt the specificity of cognitive theory of OCD to explain specific OC behavior.     

Cognitive biases and obsessive-compulsive symptoms in children: examining the role of maternal cognitive bias and child age

Objective: Multiple cognitive biases associated with adult obsessive-compulsive disorder (OCD) were tested in a clinical sample of children (ages 7-11) and adolescents (12-17) and their mothers. This study examined (a) the associations between child cognitive biases and OCD severity, (b) maternal cognitive biases and child OCD severity, and (c) maternal cognitive bias and child cognitive bias. It was hypothesized that age would significantly moderate these relationships, with stronger associations with OCD severity for cognitive bias in adolescents (relative to children), and maternal cognitive bias in younger children (relative to adolescents). Method: Forty-six children and adolescents diagnosed with OCD and their mothers completed questionnaires assessing responsibility bias, thought-action fusion (TAF), thought suppression, and metacognitive beliefs. OCD symptoms were assessed using structured diagnostic interviews and semistructured symptom interviews. Results: As predicted, age significantly moderated associations between (a) child cognitive variables and OCD severity-specifically between child responsibility and child metacognition, which were associated with OCD severity for adolescents only; (b) maternal cognitive biases and child OCD severity-specifically for maternal responsibility and thought suppression, which were significantly and positively associated with child OCD severity but not adolescent OCD severity; and (c) maternal cognitive biases and child cognitive bias-such that significant associations were evident only in the younger child sample, and only between maternal TAF self and metacognition, with child suppression and child TAF moral, respectively. Conclusion: Maternal cognitive biases are more consistently linked to greater OCD severity among younger children, whereas personal cognitive biases are associated with greater OCD symptoms in adolescents. Treatments for pediatric OCD are likely to be improved by age-specific considerations for the role of maternal and child cognitive biases associated with OCD.     

The role of comorbid disruptive behavior in the clinical expression of pediatric obsessive-compulsive disorder

This study explored the impact of disruptive behavior disorder (DBD) comorbidity on a number of theoretically relevant outcomes among 192 children and adolescents with obsessive-compulsive disorder (OCD). Youth were divided into three groups: OCD Only, OCD+DBD comorbidity and OCD+Other comorbidity. Relative to those without a comorbid condition and those with any non-DBD comorbidity, comorbid DBD was associated with greater family accommodation and less symptom resistance. Youth with comorbid DBD exhibited greater OCD symptom severity, OCD-related impairment, anxiety, and internalizing problems than those with no comorbidity. Those with comorbid DBD were over 3.6 times as likely to be taking an atypical antipsychotic medication relative to children without comorbidity. The present results suggest that comorbid DBD contributes to more severe illness presentation above and beyond an OCD diagnosis alone, and may be associated with differing pharmacotherapy prescribing practices.     

Symptom patterns in children and adolescents with obsessive-compulsive disorder (OCD)

OBJECTIVE: Obsessive-compulsive disorder (OCD) defined at the diagnostic level encompasses divergent symptoms. The present study examines symptom patterns in OCD in children and adolescents in order to search for the presence of diagnostic heterogeneity. SUBJECTS AND METHODS: Two hundred and thirteen outpatients with primary OCD participated. The patients' and primary caretakers' responses on the Children's Yale-Brown Obsessive-Compulsive Scale were used to generate severity ratings for 61 OCD symptoms, and cluster analysed them. RESULTS: A five cluster solution was judged to be the most clinically and theoretically relevant model. The clusters were named: (1) "Mental Rituals, Touching & Ordering", (2) "Contamination & Cleaning", (3) "Superstitions", (4) "Obsessions/Checking & Confessing" and (5) "Somatic Concerns". The symptom patterns of the groups differed, and three groups were particularly homogeneous. In addition, there were differences in severity, number of symptoms and age. CONCLUSIONS: OCD in children and adolescents is a heterogeneous disorder and discrepancies vis-à-vis adult studies indicate that childhood OCD may have developmentally specific traits. The sub-groups obtained are likely to have implications for the assessment of OCD symptoms in children, their prognosis and outcome in treatment research.     

The Premonitory Urge to Tic: Measurement,Characteristics, and Correlates in Older Adolescents and Adults

In addition to motor and/or vocal tics, many individuals with Tourette syndrome (TS) or chronic tic disorder (CTD) report frequent, uncomfortable sensory phenomena that immediately precede the tics. To date, examination of these premonitory sensations or urges has been limited by inconsistent assessment tools. In this paper, we examine the psychometric properties of a nine-item self-report measure, the Premonitory Urge to Tic Scale (PUTS) and examine the characteristics and correlates of the premonitory urge to tic in a clinical sample of 122 older adolescents and adults with TS or CTD. The PUTS demonstrated adequate internal consistency, temporal stability, and concurrent validity. Premonitory urges were endorsed by the majority of individuals. Most individuals reported some relief from the urges after completing a tic and being able to stop their tics even if only temporarily. Degree of premonitory urges was not significantly correlated with age, and we did not observe any gender differences. Degree of premonitory urges was significantly correlated with estimated IQ and tic severity, but not severity of comorbid obsessive–compulsive disorder or attention-deficit hyperactivity disorder. Also, it was not related to concomitant medication status. These findings represent another step forward in our understanding of the premonitory sensations associated with TS and CTD.     

Hoarding in obsessive compulsive disorder: results from a case-control study

Hoarding occurs relatively frequently in obsessive-compulsive disorder (OCD), and there is evidence that patients with hoarding symptoms have more severe OCD and are less responsive to treatment. In the present study, we investigated hoarding symptoms in 126 subjects with OCD. Nearly 30% of the subjects had hoarding symptoms; hoarding was twice as prevalent in males than females. Compared to the 90 non-hoarding subjects, the 36 hoarding individuals had an earlier age at onset of, and more severe, obsessive-compulsive symptoms. Hoarders had greater prevalences of symmetry obsessions, counting compulsions, and ordering compulsions. Hoarders also had greater prevalences of social phobia, personality disorders, and pathological grooming behaviors (skin picking, nail biting, and trichotillomania). Hoarding and tics were more frequent in first-degree relatives of hoarding than non-hoarding probands. The findings suggest that the treatment of OCD patients with hoarding symptoms may be complicated by more severe OCD and the presence of co-occurring disorders. Hoarding appears to be transmitted in some OCD families and may differentiate a clinical subgroup of OCD.     

Intensive Family-Based Cognitive-Behavioral Therapy for Pediatric Obsessive-Compulsive Disorder: Applications for Treatment of Medication Partial- or Nonresponders

Serotonin reuptake inhibitor medications and cognitive-behavioral therapy (CBT) are both effective treatments for pediatric obsessive-compulsive disorder (OCD). Despite recommendations that youth with OCD be treated with CBT alone or together with serotonin reuptake inhibitor medication, many youth are treated with medication alone or with non-CBT psychotherapy initially. Although effective, symptom remission with medication alone is rare (e.g., only 21.4% of youth achieved remission with sertraline in the Pediatric OCD Treatment Study, 2004) and residual symptoms often remain (e.g., 58% of subjects in the March et al. [1998] sertraline trial were not considered treatment responders). This paper reviews the literature on the efficacy of CBT for pediatric OCD, particularly as it relates to the treatment of youth with prior inadequate response to medication. It also describes an intensive, family-based CBT program for children and adolescents with OCD and support for its efficacy among those with prior partial- or nonresponse to medication. Finally, we present a case study of an adolescent girl with OCD who participated in the intensive treatment program after having limited benefit from medication and non-CBT psychotherapy and experienced a favorable response.     

Reliability and validity of the Yale Global Tic Severity Scale

To investigate the reliability and validity of the Yale Global Tic Severity Scale (YGTSS), 28 youth aged 6 to 17 years with Tourette's syndrome (TS) participated in the study. Data included clinician reports of tics and obsessive-compulsive disorder (OCD) severity, parent reports of tics, internalizing and externalizing problems, and child reports of depression and anxiety. All children participated in a 2nd YGTSS administration by the same rater 48 days later. Good internal consistency and stability were found for the YGTSS scores. YGTSS scores demonstrated strong correlations with parent-rated tic severity (r = .58-.68). YGTSS scores were not significantly related to measures of clinician ratings of OCD severity (r = .01-.15), parent ratings of externalizing and internalizing behavior (r = -.07-.20), and child ratings of depression (r = .02-.26) and anxiety (r = -.06 -.28). Findings suggest that the YGTSS is a reliable and valid instrument for the assessment of pediatric TS.     

Cognitive deficits of executive functions and decision‐making in obsessive‐compulsive disorder

The nature of cognitive deficits in obsessive‐compulsive disorder (OCD) is characterized by contradictory findings in terms of specific neuropsychological deficits. Selective impairments have been suggested to involve visuospatial memory, set shifting, decision‐making and response inhibition. The aim of this study was to investigate cognitive deficits in decision‐making and executive functioning in OCD. It was hypothesized that the OCD patients would be less accurate in their responses compared to the healthy controls in rational decision‐making on a version of the Cambridge gambling task (CGT) and on the color‐word interference test and on a version of the Tower of Hanoi test (tower test) of executive functioning. Thirteen participants with OCD were compared to a group of healthy controls (n = 13) matched for age, gender, education and verbal IQ. Results revealed significant differences between the OCD group and the healthy control group on quality of decision‐making on the CGT and for achievement score on the tower test. On these two tasks the OCD group performed worse than the healthy control group. The symptom‐dimension analysis revealed performance differences where safety checking patients were impaired on the tower test compared to contamination patients. Results are discussed in the framework of cognition and emotion processing and findings implicate that OCD models should address, specifically, the interaction between cognition and emotion. Here the emotional disruption hypothesis is forwarded to account for the dysfunctional behaviors in OCD. Further implications regarding methodological and inhibitory factors affecting cognitive information processing are highlighted.     

Memory and Executive Functions in Pediatric Chronic Kidney Disease

This study examined the memory and executive functioning of children and adolescents with chronic kidney disease (CKD). The sample included 20 children and adolescents with CKD ranging in age from 7.50 to 19.04 years (M = 13.41, SD = 3.20). Intellectual function for the group was within the low average to average range (M = 89.32, SD = 14.80). Of the participants with CKD, 12 were receiving maintenance dialysis therapy at the time of testing and 8 were managed with conservative therapy. Healthy controls were used as a comparison group (n = 18). This group ranged in age from 7.47 to 18.37 years (M = 12.93, SD = 2.90). Intellectual function was within the average range (M = 112.18, SD = 13.14). All subjects received a comprehensive battery of memory and executive function tasks as part of a larger neuropsychological evaluation. Preliminary examinations of the data revealed a significant difference between the groups in IQ, with the typical group being significantly higher than the CKD group. A multivariate analysis controlling for chronological age revealed significant group differences, with specific differences being noted in all of the memory functions, and the Initiation and Sustaining executive function domains. In all instances the CKD group performed lower than the typical group. The CKD group was particularly deficient in their initiation behaviors within the executive function domain. The groups did not differ on Set-Shifting or Inhibition. These findings remained present even when IQ and chronological age were controlled in the analyses, suggesting the possibility of specific encroachment of renal disease on memory and executive functions beyond the generalized effects of lower IQ. This study represents one of the most extensive examinations of memory and executive functions that has been conducted to date on children and adolescents with CKD. While pervasive dysfunction was not apparent in the children with CKD, they clearly appeared to be at risk for lower IQ as well as inefficiencies in key neurocognitive domains.     

Cool and Hot Aspects of Executive Function in Childhood Obsessive-Compulsive Disorder

Aspects of executive functioning (EF) have been put forward as endophenotypes in obsessive- compulsive disorder (OCD) and meta-analyses support EF underperformance in adult samples. Childhood-onset OCD has been suggested to constitute a separate neurodevelopmental subtype of the disorder but studies on neuropsychological functioning in childhood OCD are limited. The aim of the present study was to investigate performance-based EF in pediatric OCD using observed and latent variable analyses. A case-control design was applied including 50 unmedicated children and adolescents with OCD aged 7–17 years of which 70% were female, 50 pairwise age and gender matched non-psychiatric controls (NP) and 38 children and adolescents with mixed anxiety disorders (MA). Participants underwent structured diagnostic interviews and assessment with a battery encompassing cool EF tasks of working memory, set shifting, inhibition, and planning, and hot EF tasks of decision making and dot probe paradigm affective interference. First, groups were compared on observed variables with multilevel mixed-effects linear regression and analysis of variance. Then the latent structure of cool EF was tested with confirmatory factor analysis (CFA) and groups were compared on the CFA scores. No significant differences between groups appeared on individual cool EF tasks. On the hot EF tasks the OCD group displayed significant interference effects on the dot probe paradigm OCD-specific stimuli relative to NP, but not compared to MA and no group differences emerged for decision making. In the CFA a one-factor solution showed best fit, but the groups did not differ significantly on the resulting latent variable. The present study does not support cool or hot EF impairments in childhood OCD.     

Meta-Analysis of Intelligence Quotient (IQ) in Obsessive-Compulsive Disorder

Obsessive compulsive disorder (OCD) is associated with a moderate degree of underperformance on cognitive tests, including deficient processing speed. However, despite little research focusing on Intelligence Quotient (IQ) in OCD, it has long been speculated that the disorder is associated with elevated intellectual capacity. The present meta-analytic study was, therefore, conducted to quantitatively summarize the literature on IQ in OCD systematically. We identified 98 studies containing IQ data among individuals with OCD and non-psychiatric comparison groups, and computed 108 effect sizes for Verbal IQ (VIQ, n = 55), Performance IQ (PIQ, n = 13), and Full Scale IQ (FSIQ, n = 40). Across studies, small effect sizes were found for FSIQ and VIQ, and a moderate effect size for PIQ, exemplifying reduced IQ in OCD. However, mean IQ scores across OCD samples were in the normative range. Moderator analyses revealed no significant moderating effect across clinical and demographic indices. We conclude that, although lower than controls, OCD is associated with normative FSIQ and VIQ, and relatively lowered PIQ. These results are discussed in light of neuropsychological research in OCD, and particularly the putative impact of reduced processing speed in this population. Recommendations for utilization of IQ tests in OCD, and directions for future studies are offered.     

Recognition of Facial Expressions of Emotion by Children with Emotional and Behavioral Disorders

Interpreting and responding appropriately to facial expressions of emotion are important aspects of social skills. Some children, adolescents, and adults with various psychological and psychiatric disorders recognize facial expressions less proficiently than their peers in the general population. We wished to determine if such deficits existed in a group of 133 children and adolescents with emotional and behavioral disorders (EBD). The subjects were receiving in-patient psychiatric services for at least one of substance-related disorders, adjustment disorders, anxiety disorders, mood disorders or disruptive behavior disorders. After being read stories describing various emotional reactions, all subjects were tested for their ability to recognize the 6 basic facial expressions of emotion depicted in Ekman and Friesen's (1976) normed photographs. Overall, they performed well on this task at levels comparable to those occurring in the general population. Accuracy increased with age, irrespective of gender, ethnicity, or clinical diagnosis. After adjusting for age effects, the subjects diagnosed with either adjustment disorders, mood disorders, or disruptive behavior disorders were significantly more accurate at identifying anger than those without those diagnoses. In addition, subjects with mood disorders identified sadness significantly more accurately than those without this diagnosis, although the effect was greatest with younger children.     

Sustained attention and visual processing speed in children and adolescents with bipolar disorder and other psychiatric disorders

To investigate the cognitive functioning of children and adolescents with bipolar illness, 112 child and adolescent psychiatric inpatients and day-hospital patients at a state psychiatric hospital were administered the Wechsler Intelligence Scale for Children-III (WISC-III) as part of an admission psychological assessment. There were 22 patients with Bipolar Disorder and 90 with other psychiatric disorders; all were between 8 and 17 years of age. The patients with Bipolar Disorder had a mean age of 14 yr., a mean Verbal IQ of 78, a mean Performance IQ of 76, and a mean Full Scale IQ of 75. When their WISC-III scores were compared with those who had Schizophrenia Spectrum disorders (Schizophrenia and Schizoaffective Disorder), Psychosis Not Otherwise Specified, Attention Deficit Hyperactivity Disorder, and Conduct Disorder and Oppositional Defiant Disorder, there were no significant between-group mean differences for Verbal IQ, but patients with Bipolar Disorder had a significantly lower mean Performance IQ than those with ADHD and those with Conduct Disorder and Oppositional Defiant Disorder. Contrary to the expectation that the patients with Bipolar Disorder might have better sustained attention (higher Digit Span scores) than those with Schizophrenia Spectrum disorders and worse visual processing speed (lower Coding scores) than the other diagnostic groups, the bipolar patients' Digit Span and Coding scores did not differ significantly from those of the other groups. The patients with Psychosis, Not Otherwise Specified had significantly lower mean Performance IQ, Full Scale IQ, and Coding than the ADHD and the Conduct Disorder and Oppositional Disorder groups.     

Sleep-Related Problems in Pediatric Obsessive-Compulsive Disorder and Intensive Exposure Therapy

Limited research has examined sleep-related problems (SRPs) among children and adolescents with obsessive-compulsive disorder (OCD). The present study addresses this gap by investigating preliminary associations between SRPs, demographic factors (gender and age), family variables (family accommodation and parental stress), and clinical factors (medication status, internalizing and externalizing symptoms, OCD severity, OCD-related impairment), and treatment outcomes in a sample of 103 youth (aged 7 to 17 years; 53% female) with a primary diagnosis of OCD. Clinician, parent, and child measures were used to assess demographic, family, and clinical predictors. SRPs were assessed using an 8-item measure comprising items of the Child Behaviour Checklist, Child Depression Inventory, and Multidimensional Anxiety Scale for Children as used in previous studies. Results showed that SRPs were highly prevalent among this sample and that more SRPs were associated with younger age, internalizing problems, and functional impairment. However, SRPs were not an independent predictor of OCD severity, impairment, or treatment response. Preliminary findings suggest that SRPs among youth with OCD may be more strongly associated with broader internalizing symptoms than with OCD itself. Future longitudinal research is warranted to further explore the complexity of SRPs when co-occurring with pediatric OCD.     

Effects of IQ on Executive Function Measures in Children with ADHD

The present study compared children with Attention-Deficit Hyperactivity Disorder (ADHD) and controls on a selected set of clinical measures of executive function (EF). A total of 92 children (51 ADHD, 41 control), ages 6-16, completed measures chosen from a larger neuropsychological battery to illustrate diverse components of the EF construct (planning, inhibitory control, response preparation, memory search). The selected measures were moderately correlated with one another, and moderately correlated with IQ. After controlling for age, sex, presence of learning disability (LD), ADHD, and IQ test version, Full Scale IQ was significantly related to four of the five selected EF measures. A second analysis showed group differences on the EF measures at different IQ levels. After covarying for age, there was a significant multivariate effect for IQ level (average, high average, superior) and a significant multivariate interaction between group (ADHD vs. control) and IQ level. Three of the five selected EF measures showed significant univariate group effects (controls performing better than ADHD) at the average IQ level; however, there were no significant group differences between children with ADHD and controls at high average or superior IQ levels. These results suggest that clinical measures of EF may differ among children with ADHD and controls at average IQ levels, but there is poorer discriminatory power for these measures among children with above average IQ.