Associated psychopathology in children with both ADHD and chronic tic disorder

An observational study of emotion regulation in children with Tourette syndrome

BACKGROUND

Explosive outbursts occur in 25%-70% of children with Tourette syndrome (TS) and may cause more distress than the tics themselves. Previous studies have indicated that a comorbid diagnosis of attention-deficit/hyperactivity disorder (ADHD) is associated with emotional dysregulation in TS; however, this relationship has almost exclusively been studied using parent-reported questionnaires.

METHODS

We examined emotion regulation (ER) with an observational measure in 150 medication-naïve children aged 7-12 allocated to four groups: Forty-nine children with TS, 23 children with ADHD, 16 children with TS + ADHD, and 62 typically developing controls. We assessed participants' ER ability, as well as parent-child interactions in the context of a complex puzzle task, and coded the observed behavior with the Tangram Emotion Coding Manual (TEC-M). We examined group differences in ER, as well as associations between ER and severity of symptoms pertaining to TS and ADHD.

RESULTS

Children with TS did not differ from controls in their ER ability. However, children with ADHD and TS + ADHD had more problems with ER than those with TS only and controls. Finally, parents of children with ADHD displayed more tension during the experimental task. ER ability was not associated with tic severity nor premonitory urges; however, better ER ability was associated with less severe symptoms of ADHD.

CONCLUSIONS

This study is the first to evaluate ER with an observational, clinician-rated measure in a controlled social setting in children with TS. Our findings support earlier questionnaire-based studies by showing impaired ER in children with TS + ADHD, but not in children with TS without comorbidity. These findings inform our understanding of the phenomenology of emotional dysregulation in TS and the role of comorbid disorders.

Aggressive symptoms in children with tic disorders

Episodes of explosive anger and aggression are reported in patients with tic disorders and probably contribute to psychosocial stress and low quality of life. The source of these symptoms is controversial. The objective of the study was to study the relationship between tic disorders, their associated comorbidities, and aggressive behavior. The cohort included 47 children and adolescents (age 7-17 years) with Tourette syndrome or other chronic tic disorders attending a tertiary pediatric Tourette clinic. Associated psychopathology was assessed with the Yale Global Tic Severity Scale, Yale Brown Obsessive Compulsive Scale, Conners ADHD Rating Scale, Screen for Child Anxiety-Related Emotional Disorders, and Child Depression Inventory. Aggression was assessed with the Overt Aggression Scale and scores were compared with a group of 32 healthy age- and sex-matched children. There were no significant differences in aggression scores between the children with tic disorders and controls. Verbal aggression was the most prevalent type of aggression, found in 70% of the patients with tic disorders. The level of aggression was not correlated to tic severity. Comorbid attention-deficit hyperactivity disorder and obsessive-compulsive disorder increased the probability of aggressive behavior in patients with tic disorders. On regression analysis, the only significant predictor of aggression was the severity of attention-deficit hyperactivity disorder. This study suggests that there is no difference in aggressive behavior between children with tics without comorbidities and healthy children. It is possible that aggressive behavior in children with tic disorders is predominantly associated with comorbid attention-deficit hyperactivity disorder.

Anxiety in boys with attention-deficit/hyperactivity disorder with and without chronic multiple tic disorder

OBJECTIVE

This study examined the psychosocial and behavioral concomitants of anxiety in clinic-referred boys with attention-deficit/hyperactivity disorder (ADHD) with and without chronic multiple tic disorder (CMTD).

METHOD

ADHD boys with (n = 65) and without (n = 94) CMTD were evaluated with measures of psychiatric symptoms, mental health risk factors, and academic and social performance.

RESULTS

Boys with CMTD evidenced more severe anxiety and less social competence and were more likely to be living with only one biological parent than the ADHD Only group, but the magnitude of group differences was generally small. The severity of generalized anxiety, separation anxiety, social phobia, and obsessive-compulsive symptoms were uniquely associated with a different pattern of risk factors, and there was some evidence that these patterns differed for the two groups of boys.

CONCLUSION

Boys with CMTD had a relatively more severe and complex pattern of anxiety that was associated with different clinical features, all of which suggests that ADHD plus CMTD might better be conceptualized as a distinct clinical entity from ADHD Only. However, findings from the extant literature are mixed, and therefore this remains a topic for further study.

Comparative study of children with ADHD only, autism spectrum disorder + ADHD, and chronic multiple tic disorder + ADHD

OBJECTIVE

Identification of differences among children with ADHD only, autism spectrum disorder (ASD)+ADHD, and chronic multiple tic disorder (CMTD)+ADHD may lead to better understanding of clinical phenotypes.

METHOD

Children were evaluated using the parent- and teacher-completed questionnaires.

RESULTS

All three groups were highly similar in severity of oppositional defiant disorder and conduct disorder symptoms; however, the ASD+ADHD group generally exhibited the most severe anxiety, although the CMTD+ADHD group had the most severe generalized anxiety. The two comorbid groups had the most involved medical histories and the greatest likelihood of a family history of psychopathology.

CONCLUSION

Groups differed in clinically meaningful ways, and the apparent association between tics and anxiety may explain in part the elevated levels of anxiety in both comorbid groups. Collectively, results suggest that ADHD may be better conceptualized as a family of interrelated syndromes defined in part by comorbid conditions and that continued research is clearly warranted.

Comorbid behavioural problems in Tourette's syndrome are positively correlated with the severity of tic symptoms

OBJECTIVE

We studied the comorbid behavioural and mood problems in children with non-psychiatric Tourette's syndrome (TS) and their relationship with severity of tic disorder.

METHOD

Sixty-nine TS children and 69 healthy controls were assessed by Child Behavior Checklist (CBCL) and Yale Global Tic Severity Scale (YGTSS). The relationships between behavioural problems and severity of tic symptoms were analysed statistically by comparison, correlation and multiple linear regression.

RESULTS

Tourette's syndrome patients scored significantly lower (p<0.01) on the CBCL competency subscales and total score, and higher on all behavioural problem subscales and total score (p<0.01). Expectedly, the TS children had lower social competence than normal children. Among the TS children, the severity of tic symptoms is positively correlated with the severity of overall impairment in school and social competence. When the behavioural and mood problems commonly associated with TS were studied in detail, we found that delinquent behaviour, thought problems, attention problems, aggressive behaviour and externalizing are positively correlated with severity of tic symptoms.

CONCLUSION

The findings indicated that children with TS-only also had a broad range of behavioural problems, and some of these were related to the severity of tic symptoms.

Clinical significance of tics and attention-deficit hyperactivity disorder (ADHD) in children with pervasive developmental disorder

The goal of this study was to examine the clinical significance of co-occurring tics and attention-deficit hyperactivity disorder (ADHD) as indicators of a more complex symptomatology in children with and without pervasive developmental disorder. Parents and teachers completed a Diagnostic and Statistical Manual of Mental Disorders-IV-referenced rating scale for 3- to 5- (n = 182/135) and 6- to 12- (n = 301/191) year-old children with pervasive developmental disorder and clinic controls, respectively. The percentage of children with tic behaviors varied with age: preschoolers (25%, 44%) versus elementary schoolchildren (60%, 66%) (parent and teacher ratings, respectively). For many psychiatric symptoms, screening prevalence rates were highest for the ADHD + tics group and lowest for the group with symptoms of neither, but the pattern of group differences varied by age group and informant. In general, there were few differences between the ADHD only and tics only groups. The pattern of ADHD/tic group differences was similar for both children with and without pervasive developmental disorder. We concluded that these findings support the notion that the co-occurrence of ADHD and tics is an indicator of a more complex psychiatric symptomatology in children with pervasive developmental disorder.

Behavioural problems and psychiatric symptoms in 5-13 year-old Swedish children-a comparison of parent ratings on the FTF (Five to Fifteen) with the ratings on CBCL (Child Behavior Checklist)

As part of the validation procedure of a new parent questionnaire ("Five to Fifteen" or the FTF) a random sample of 1500 children aged 5-13 years from the Swedish Population Register (SPAR) was approached. The FTF and the Child Behavior Checklist (CBCL) were sent to the parents of the children together with questions about background conditions. After two reminders the response rate was 55.6%. The final sample had a mean age of 9.12 years (SD=1.89) and a sex distribution with 55% boys and 45% girls. Analysis of attrition did not support overrepresentation of foreigners/immigrants in the attrition population. FTF like CBCL showed sensitivity to sociodemographic variables. On the FTF fewer problems were indicated for girls in all domain scales, whereas this was true for the summary scale Externalizing and Mixed problems of the CBCL. The effects of age and area of residence were slight, but parental education was negatively related to all domain scales of the FTF and to all the CBCL scales. The intercorrelations of the FTF and CBCL scales with common content showed substantial overlap supporting the validity of the FTF scales. The correlation between scales within the FTF however also indicates a substantial comorbidity. This is also supported by the substantial correlation between problem score of the FTF domains perception, language, motor skills and the CBCL scale scores Attention, Social problems as well as the summary scale Mixed problems. These findings indicate that problems with inattention and social relations are shared across the various problem domains. Factor analysis of the FTF subdomain scores resulted in two factors, one representing learning problems and the other behavioural/emotional problems. Despite the low response rate the representativity of the sample was supported by the fact that the total problem score of CBCL was very similar to that of another Swedish sample with a relatively high response rate. The finding of a frequency of AD/HD symptoms in the FTF rating corresponding to the figures of prevalence of AD/HD in several international epidemiological studies could also be seen as support for the relevance of the findings. Thus, the results give support to the usefulness of the FTF questionnaire as an instrument that can help in delineating specific problem areas within the field of child neuropsychiatry. Through the comparison with the CBCL the validity of the FTF for the parts that the two instruments share could be ascertained and the value of tapping a broader problem area could be elucidated.

The Tourette's Disorder Scale (TODS): development, reliability, and validity

To address the lack of a simple and standardized instrument to assess overall illness severity of Tourette's disorder (TD), the authors developed and tested a 15-item scale to measure a broad range of common symptoms including tics, inattention, hyperactivity, obsessions, compulsions, aggression, and emotional symptoms. Independent investigators used the 15-item Tourette's Disorder Scale (TODS) to assess 60 TD patients who were taking part in a double-blind placebo-controlled multicenter 8-week treatment study. Interrater reliability, internal consistency, convergent and discriminant validity, and sensitivity to change were examined. The TODS was associated with good interrater reliability, excellent internal consistency, and favorable levels of validity and sensitivity to change. Individual TODS items showed good convergent and discriminant validity against other measures. The TODS is a simple, efficient way for clinicians and parents to rate the severity of multiple symptoms commonly found in patients with Tourette's disorder.

Movement Disorders

This chapter covers five movement disorders: Parkinson's disease, dystonia, tic disorders, Huntington's disease, and essential tremor. These disorders demonstrate many of the most common challenges encountered in the epidemiologic investigation of movement disorders. Each section includes a description of the disease, followed by a review of descriptive studies (disease incidence, prevalence, and mortality studies), and discussion of genetic and environmental risk factors for the disorder. At the end of each section, directions for future studies are discussed.

Ten-year review of rating scales. V: scales assessing attention-deficit/hyperactivity disorder

OBJECTIVE

This article summarizes information on scales assessing attention-deficit/hyperactivity disorder (ADHD) in children and adolescents.

METHOD

The authors sampled articles on ADHD over the past decade. Several popular older ADHD measures have recently been revised, and new ADHD scales have been developed. The authors selected primarily ADHD scales based on the DSM-IV construct of ADHD that also have multiple literature citations. They then reviewed their psychometric properties. Those with adequate psychometric functioning plus considerable literature citations, known wide usage in clinical practice, or a current niche are presented here.

RESULTS

Several rating scales consistent with the DSM-IV conceptualization of ADHD are now available for use in both home and school settings. Many of the instruments demonstrate solid psychometric properties and a strong normative base. However, some popular scales have not been adequately investigated. Some measures are restricted to the comprehensive assessment of ADHD, whereas others also include symptoms of other disorders. The potential applications for these scales with youths diagnosed with ADHD are broad.

CONCLUSIONS

Rating scales can reliably, validly, and efficiently measure DSM-IV-based ADHD symptoms in youths. They have great utility in research and clinical work, assist treatment planning, and help to ensure accountability in practice.

Disruptive behavior in children with Tourette's syndrome: association with ADHD comorbidity, tic severity, and functional impairment

OBJECTIVE

To examine the association of disruptive behavior with social, adaptive, and family functioning in Tourette's syndrome (TS) with and without comorbid attention-deficit/hyperactivity disorder (ADHD).

METHOD

The sample included 207 children (144 boys and 63 girls) between the ages of 7 and 18 years. Forty-two children received a diagnosis of TS-only, 52 received a diagnosis of ADHD-only, 52 children had TS+ADHD, and there were 61 unaffected control children. Best-estimate DSM-IV diagnoses were assigned on the basis of structured interviews and clinical ratings. Dependent measures included parent and teacher ratings of disruptive behavior, parent ratings of social and family functioning, and the Vineland Adaptive Behavior Scales.

RESULTS

Children with TS-only did not differ from unaffected controls on the parent ratings of aggression and delinquent behavior or on the teacher ratings of conduct problems. By contrast, children with TS+ADHD were rated significantly above unaffected controls and similar to children with ADHD-only on these indices of disruptive behavior. Hierarchical regression analyses revealed that aggression and delinquency scores added unique contributions to impairment in social and family functioning, controlling for age, gender, and diagnostic status.

CONCLUSIONS

Comorbid ADHD is highly associated with disruptive behavior and functional impairment in children with TS. When disruptive behavior problems are present, there is an additional burden on children's social and family functioning.

Anxiety and depression symptoms and response to methylphenidate in children with attention-deficit hyperactivity disorder and tic disorder

This study examined response to methylphenidate in children with attention-deficit/hyperactivity disorder (ADHD) and chronic multiple tic disorder. The primary goal was to determine if children with anxiety or depression symptoms showed a less favorable response to treatment. Subjects were 38 prepubertal children who participated in an 8-week, double-blind, placebo-controlled, methylphenidate crossover evaluation. Treatment effects were assessed with direct observations of child behavior in public school and clinic settings; rating scales completed by parents, teachers, and clinicians; and laboratory analogue tasks. There was little evidence (group data) that children with anxiety or depression symptoms responded in a clinically different manner to methylphenidate than youngsters who did not exhibit these symptoms, particularly in school observations of the core features of ADHD. Seeming differences between children with and without comorbid anxiety or depression symptoms and drug response are likely explained by differences in pretreatment levels of negativistic behaviors (i.e., symptoms of oppositional defiant disorder or conduct disorder). Methylphenidate appears to be effective for the management of ADHD behaviors in children with mild to moderate anxiety or depression symptoms; nevertheless, much research remains to be performed in this area.

Comparative study of the behavioral and neuropsychologic characteristics of tic disorder with or without attention-deficit hyperactivity disorder (ADHD)

To study the nature of the comorbidity of tic disorder and attention-deficit hyperactivity disorder (ADHD), patients with tic disorder with or without ADHD were compared on the basis of clinical ratings and neuropsychologic tests. Seventy-eight children were involved in this study: 16 with tic disorder, 19 with comorbid tic disorder and ADHD, 21 with ADHD, and 22 normal controls. Rating scales for ADHD, the Child Behavior Checklist and the Yale Global Tic Severity Scale, were completed in clinical groups. To identify differences in neuropsychologic function among the four groups, the results of seven neuropsychologic tests of global cognitive abilities, attention, information-processing capacity, and fine motor skill were compared. On most behavioral and neuropsychologic tests, the tic disorder with ADHD and the ADHD groups demonstrated similar performance patterns and marked deficits compared with the tic disorder and the control groups, whereas in most of the attention tests, the ADHD group made more commission errors than the tic disorder with ADHD group. These findings suggest that the tic disorder with ADHD group has marked cognitive deficits and behavioral disturbance similar to the ADHD group, whereas the tic disorder group is more similar to the controls. The tic disorder with ADHD group might represent a true comorbidity of the two disorders.

Multicenter, double-blind, placebo-controlled study of mecamylamine monotherapy for Tourette's disorder

OBJECTIVE

The safety and efficacy of mecamylamine as a monotherapy in children and adolescents with Tourette's disorder (TD) was investigated in an 8-week multicenter, double-blind, placebo-controlled study.

METHOD

Eligible subjects included subjects with TD (DSM-IV), with a naturalistic mix of comorbid diagnoses, nonsmokers, aged 8 to 17 years, whose behavioral and emotional symptoms (according to parents) were more disturbing than tics. After a washout period of all psychotropic medication, subjects were randomly assigned to either mecamylamine (n = 29) or placebo (n = 32). Mecamylamine doses ranged from 2.5 to 7.5 mg/day. Primary efficacy measures included the Tourette's Disorder Scale-Clinician Rated (TODS-CR) and 21-point Clinical Global Improvement scale; secondary efficacy measures included the Yale Global Tic Severity Scale and a rage-attack scale (RAScal).

RESULTS

Of the 61 subjects who were randomized, 50 (82%) completed at least 3 weeks on medication and 38 (62%) completed the full 8-week trial. Study withdrawals included 12/29 on mecamylamine and 11/32 on placebo. For the total sample, mecamylamine was no more effective than placebo on any of the outcome measures. However, an item analysis of the TODS-CR suggested that mecamylamine may have reduced sudden mood changes and depression in moderately to severely affected subjects. Except for a slight increase in heart rate during the 1st week in both the mecamylamine and the placebo groups, there where no significant mecamylamine-related changes in vital signs, electrocardiogram, complete blood cell count, or blood chemistry values.

CONCLUSIONS

Mecamylamine, in doses up to 7.5 mg/day, is well tolerated in children and adolescents, but as a monotherapy it does not appear to be an effective treatment for tics or for the total spectrum of symptoms associated with TD. However, further studies should be conducted to investigate its possible therapeutic effects in subjects with comorbid mood disorders and as an adjunct to neuroleptic medication.

Tics and its disorders

Tourette syndrome (TS) is familial neuropsychiatric disorder that is characterized by motor and phonic tics that begin in childhood. Once thought of as a rare and debilitating disorder, in the last decade new scientific knowledge suggests that TS and related tic disorders are more common and less debilitating for the majority of individuals. Evidence points toward a spectrum of TS symptomatology that extends beyond the tics disorder to probably include obsessive-compulsive disorder, attention deficit hyperactivity disorder, and mood disorders. Tourette syndrome and its differential diagnosis are discussed in this article with a focus on new developments in classification, etiology, epidemiology, genetics, pathophysiology, and clinical management.

Explosive outbursts in children with Tourette's disorder

OBJECTIVE

Sudden, explosive outbursts of behavior occur in some children with Tourette's disorder (TD). The etiology of these symptoms is unknown. This study investigated the relationship between explosive outbursts, TD, and its comorbid disorders.

METHOD

Tic type and severity and the presence of specific comorbid disorders were compared in 37 children with TD and explosive outbursts and 31 children with TD who did not have such symptoms.

RESULTS

Children with TD and explosive outbursts were more likely to demonstrate significant comorbid conditions, particularly attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, and oppositional defiant disorder. Tic type and severity did not appear related to the presence of explosive outbursts. A highly significant relationship was demonstrated between the number of comorbid psychiatric diagnoses and explosive outbursts.

CONCLUSIONS

Explosive outbursts in children with TD resemble intermittent explosive disorder and may reflect dysregulation of diverse domains of brain function. The presence of such symptoms should alert the clinician to underlying comorbid conditions.

Informativeness of structured diagnostic interviews in the identification of Tourette's disorder in referred youth

Although specialized programs have greatly advanced the treatment of youth with Tourette's disorder (TD), not all children with TD reach such programs, raising questions as to whether TD is adequately identified outside specialized settings. There is thus a need for evidence that cases identified in the nonspecialty setting are "true cases." Because structured diagnostic interview methodology can reduce errors of omission, this approach can facilitate the identification of TD in referred youth outside specialized programs. Similarities between cases ascertained in specialty and nonspecialty settings would suggest that those identified in the nonspecialty setting were indeed "true cases." Comparisons were made between youth with TD ascertained through a specialized TD program who had both a structured diagnostic interview-derived diagnosis of TD plus an expert evaluation of TD (N = 103), with youth ascertained through a non-TD specialized pediatric psychopharmacology program who had a structured diagnostic interview-derived diagnosis of TD (N = 92). Irrespective of ascertainment source, children with structured interview-derived diagnosis of TD shared similar correlates in terms of tic severity, mean age of onset and duration of tics, as well as patterns of comorbidity well known to be associated with TD in clinical samples. Children meeting diagnostic criteria for TD on structured diagnostic interviews share similarities and patterns of clinical correlates, irrespective of ascertainment through a specialized TD or non-TD specialized clinic. These findings support the usefulness of structured diagnostic interview methodology as a diagnostic aid for the identification of TD in non-TD specialized settings and facilitate delineation of patterns of comorbidity.

Distinguishing illness severity from tic severity in children and adolescents with Tourette's disorder

OBJECTIVE

To examine whether tic severity, comorbid disorders, or both are associated with illness morbidity in youths with Tourette's disorder (TD).

METHOD

Subjects were 156 consecutively referred youths (aged 5-20 years) who met DSM-III-R criteria for Tourette's disorder at a major academic medical center. All subjects were evaluated with a clinical interview by a child and adolescent psychiatrist and an assessment battery that included the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic version. Statistical analysis used chi 2 and multivariate logistic regression.

RESULTS

Nineteen (12%) of the 156 youths with TD required psychiatric hospitalization. Current age, TD severity, TD duration, obsessive-compulsive disorder, psychosis, major depression, bipolar disorder, panic disorder, and overanxious disorder were significant univariate predictors of psychiatric hospitalization (p < .01). While tic severity was marginally significant as a predictor of psychiatric hospitalization (p < .05), major depression (p < .016) and bipolar disorder (p < .001) were robust predictors of psychiatric hospitalization, even after statistical adjustment for collinearity and correction for all other variables assessed.

CONCLUSION

The findings indicate that comorbid mood disorders are strongly associated with illness morbidity in youths with TD, highlighting the importance of attention to comorbidity in patients with TD.

Anxiety disorders and tic severity in juveniles with Tourette's disorder

OBJECTIVE

It was hypothesized that comorbidity with anxiety disorders would predict tic severity in youths with Tourette's disorder (TD).

METHOD

Subjects were 190 youths meeting DSM-III-R diagnostic criteria for TD who were consecutively referred to a pediatric psychopharmacology program between 1994 and 1997. Subjects were initially evaluated with a clinical interview and the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic version. Statistical analysis used t tests, chi 2 tests, and logistic regression analysis.

RESULTS

One hundred thirty-four subjects were classified as mild/moderate and 56 as severe TD cases. No meaningful differences were found in socioeconomic status, gender distribution, or age at onset of TD between the 2 groups. The 2 groups could not be differentiated by the presence of comorbid mood or disruptive behavior disorders including attention-deficit hyperactivity disorder. Although obsessive-compulsive disorder (OCD) was overrepresented among the severe TD cases, the difference failed to reach statistical significance. Excluding social and simple phobias, all other anxiety disorders were more clearly overrepresented among subjects with severe TD; separation anxiety disorder most robustly predicted tic severity, irrespective of the presence of OCD or other anxiety disorders.

CONCLUSION

Findings suggest that non-OCD anxiety disorders in general and separation anxiety disorder in particular may be significantly associated with tic severity in referred TD patients.

Comparison of internalizing and externalizing symptoms in children with attention-deficit hyperactivity disorder with and without comorbid tic disorder

This study examined the relation between internalizing and externalizing symptoms in two groups of prepubertal boys (with and without multiple chronic tic disorder) with diagnosed attention-deficit hyperactivity disorder (ADHD). Parents and teachers completed the Child Behavior Checklist (CBCL) and Teacher's Report Form (TRF), respectively. Children were carefully evaluated for the absence of a chronic tic disorder. Boys with ADHD and chronic multiple tic disorder (ADHD/+tics) received significantly higher (p = .0032, Bonferroni correction) scores for the Anxious/Depressed, Thought Problems, and Attention Problem scales of the CBCL and the Delinquent Behavior, Thought Problems, and Somatic Complaints scales of the TRF than did boys without chronic tic disorder (ADHD/-tics). Although many of the individual items that differentiated (p < .05) the two groups of boys pertained to behaviors that characterize motor tics, obsessions, or compulsions, the ADHD/+tics group exhibited higher rates of anxious behavior (CBCL) and obscene language (TRF) than did the ADHD/-tics group. Anxiety/depressive symptoms were associated with aggressive/oppositional behavior in both samples. Children with mild tic disorder were more similar (CBCL) to ADHD/-tics boys than they were to children with more severe tic disorder. The relatively higher rate of comorbidity in the ADHD/+tics group suggests that tics may be a marker for more severe symptomatology in clinic-referred samples of children with ADHD. Furthermore, these data suggest that it is not the presence, per se, but rather the severity of tic disorder that is associated with higher rates of emotional and behavioral disturbances.

Children with ADHD and tic disorder and their classmates: behavioral normalization with methylphenidate

OBJECTIVES

To examine behavioral differences between children with attention-deficit hyperactivity disorder (ADHD) and tics and their peers and the extent to which methylphenidate (0.1, 0.3, and 0.5 mg/kg) normalized the behavior of probands and indirectly influenced the behavior of peers (treatment spillover).

METHOD

Thirty-four prepubertal children with ADHD and chronic tic disorder (who were participating in a double-blind, placebo-controlled methylphenidate evaluation) and their peers were observed for approximately 20 hours in the school setting (classroom seatwork activities, lunchroom, and playground).

RESULTS

Children with ADHD and tics were more inattentive and more disruptive in the classroom and more aggressive in all school settings than their peers. Although treatment with methylphenidate made probands less easily distinguished from their peers (normalization), many children still scored in the deviant range for at least one ADHD behavior when receiving the 0.5-mg/kg dose. There was little evidence that peer behavior improved as a function of the proband's dose of medication.

CONCLUSIONS

Although conventional doses of methylphenidate produced dramatic clinical improvement in ADHD-related behavior, complete behavioral normalization is often not attained.

Attention Deficit Hyperactivity Disorder (ADHD): Selected review of causes, comorbidity and treatment

A limited review of the causes, comorbidity, diagnosis and treatment is offered to emphasize the difficulties in diagnosing and treating Attention Deficit Hyperactivity Disorder and Hyperkinetic Disorder. Some of the difficulties include controversies about the existence of a separate disorder, the changes in symptoms with age, the short-lived improvement on medication and the claims of unsubstantiated treatments. This selected review should help the reader to consider recent findings in the aetiology, diagnosis and treatment of ADHD.