Advancing early detection of autism spectrum disorder by applying an integrated two-stage screening approach

BACKGROUND

Few field trials exist on the impact of implementing guidelines for the early detection of autism spectrum disorders (ASD). The aims of the present study were to develop and evaluate a clinically relevant integrated early detection programme based on the two-stage screening approach of Filipek et al. (1999), and to expand the evidence base for this approach.

METHODS

The integrated early detection programme encompassed: 1) training relevant professionals to recognise early signs of autism and to use the Early Screening of Autistic Traits Questionnaire (ESAT; Dietz, Swinkels et al., 2006; Swinkels, van Daalen, van Engeland, & Buitelaar, 2006), 2) using a specific referral protocol, and 3) building a multidisciplinary diagnostic team. The programme was evaluated in a controlled study involving children in two regions (N = 2793, range 0-11 years). The main outcome variables were a difference in mean age at ASD diagnosis and a difference in the proportion of children diagnosed before 36 months.

RESULTS

ASD was diagnosed 21 months (95% CI 9.6, 32.4) earlier in the experimental region than in the control region during the follow-up period, with the mean age at ASD diagnosis decreasing by 19.5 months (95% CI 10.5, 28.5) from baseline in the experimental region. Children from the experimental region were 9.4 times (95% CI 2.1, 41.3) more likely than children from the control region to be diagnosed before age 36 months after correction for baseline measurements. Most of these early diagnosed children had narrowly defined autism with mental retardation.

CONCLUSIONS

The integrated early detection programme appears to be clinically relevant and led to the earlier detection of ASD, mainly in children with a low IQ.

An Internet version of the Diagnostic Interview Schedule for Children (DISC-IV): correspondence of the ADHD section with the paper-and-pencil version

The authors recently developed an Internet version of the Diagnostic Interview Schedule for Children-Version 4 (DISC-IV), parent version (D. Shaffer, P. Fisher, C. P. Lucas, M. K. Dulcan, & M. E. Schwab-Stone, 2000), with the main purpose of using it at home without an interviewer. This offers many advantages (e.g., extended applicability, fast communication, reduction of costs) but requires thorough study of correspondence between diagnostic outcomes of the interview and self-administered Internet versions. This is the 1st study to report on Internet administration of the DISC-IV. Using the attention-deficit/hyperactivity disorder (ADHD) section, the authors investigated whether the 2 versions yielded the same diagnostic outcome. Parents (N = 120) of patients visiting a child and adolescent psychiatry outpatient clinic were randomly divided into 4 groups, each completing 1 test and about 2 weeks later another according to 1 of these patterns: Internet-interview, interview-Internet, interview-interview, and Internet-Internet. Correspondence between the Internet and interview versions at the level of symptom scores was excellent, and correspondence with respect to the presence/absence of ADHD was good. Although highly comparable diagnostic outcomes between self-administration through the Internet and interviewer administration were found, further study using other DISC-IV modules is required.

Atomoxetine for attention-deficit/hyperactivity disorder symptoms in children with pervasive developmental disorders: a pilot study

OBJECTIVE

This pilot study examined the effects of atomoxetine on attention-deficit/hyperactivity disorder (ADHD) symptoms and autistic features in children with pervasive developmental disorders (PDD).

METHOD

Twelve children (aged 6-14 years) with PDD accompanied by ADHD symptoms entered a 10-week open-label study with atomoxetine (1.19 +/- 0.41 mg/kg/day). Response was assessed by using parent and clinician rating scales with change in the ADHD-Rating Scale (ADHDRS) as primary outcome measure.

RESULTS

Atomoxetine reduced ADHD-symptoms as measured by the ADHDRS (44% decrease vs. baseline, p < 0.003), the Conners' Parent Rating Scale-R:S (CPRS-R) (25% in the subscale "Cognitive Problems," p < 0.028; 32% in "Hyperactivity," p < 0.030; and 23% in "ADHD index," p < 0.023). We found a reduction of 21% (p = 0.071) for changes in the subscale "Hyperactivity" of the Aberrant Behavior Checklist (ABC). No change was found in any of the other ABC subscales, nor in the subscale "Oppositional" of the CPRS-R. Five patients (42%) discontinued because of side effects. Gastrointestinal symptoms, irritability, sleep problems, and fatigue were the most frequent side effects.

CONCLUSIONS

These preliminary findings indicate that atomoxetine may be a promising new agent in the treatment of ADHD symptoms in children with PDD. However, children with PDD may have a higher vulnerability for some of the known side-effects of atomoxetine.

Long-term effects of risperidone in children with autism spectrum disorders: a placebo discontinuation study

OBJECTIVE

The short-term benefit of risperidone in ameliorating severe disruptive behavior in pediatric patients with autism spectrum disorders is well established; however, only one placebo-controlled, long-term study of efficacy is available.

METHOD

Thirty-six children with an autism spectrum disorder (5-17 years old) accompanied by severe tantrums, aggression, or self-injurious behavior, started 8-week open-label treatment with risperidone. Responders (n = 26) continued treatment for another 16 weeks, followed by a double-blind discontinuation (n = 24; two patients discontinued treatment because of weight gain) consisting of either 3 weeks of taper and 5 weeks of placebo only or continuing use of risperidone. Relapse was defined as a significant deterioration of symptoms based on clinical judgment and a parent questionnaire.

RESULTS

Risperidone was superior to placebo in preventing relapse: this occurred in 3 of 12 patients continuing on risperidone versus 8 of 12 who switched to placebo (p = .049). Weight gain, increased appetite, anxiety, and fatigue were the most frequently reported side effects.

CONCLUSIONS

This study indicates the effectiveness of risperidone during a period of several months, reducing disruptive behavior in about half of the children with autism spectrum disorders. The results provide a rationale for the continuing use of risperidone beyond 6 months, although considerable weight gain can limit the use of this agent.

Differential effects of DRD4 and DAT1 genotype on fronto-striatal gray matter volumes in a sample of subjects with attention deficit hyperactivity disorder, their unaffected siblings, and controls

Genetic influences on behavior are complex and, as such, the effect of any single gene is likely to be modest. Neuroimaging measures may serve as a biological intermediate phenotype to investigate the effect of genes on human behavior. In particular, it is possible to constrain investigations by prior knowledge of gene characteristics and by including samples of subjects where the distribution of phenotypic variance is both wide and under heritable influences. Here, we use this approach to show a dissociation between the effects of two dopamine genes that are differentially expressed in the brain. We show that the DAT1 gene, a gene expressed predominantly in the basal ganglia, preferentially influences caudate volume, whereas the DRD4 gene, a gene expressed predominantly in the prefrontal cortex, preferentially influences prefrontal gray matter volume in a sample of subjects including subjects with ADHD, their unaffected siblings, and healthy controls. This demonstrates that, by constraining our investigations by prior knowledge of gene expression, including samples in which the distribution of phenotypic variance is wide and under heritable influences, and by using intermediate phenotypes, such as neuroimaging, we may begin to map out the pathways by which genes influence behavior.

Association of common cold with exacerbations in pediatric but not adult patients with tic disorder: a prospective longitudinal study

Cross-sectional data and case studies suggest a temporal relationship between fluctuations in tic severity and preceding infections. In this study, we aimed to examine this possible relationship in a prospective longitudinal design. Two groups of tic disorder patients were included, a pediatric group between 7 and 15 years of age (n = 20), and an adult group over 15 years of age (n = 41). During a 24-week period, participants were asked to fill out weekly self questionnaires regarding the presence of tic exacerbations and the experience of the common cold. In addition, 6 throat swabs were taken at monthly intervals and cultured for streptococci; also, 3 serial serum assessments of streptococcal antibodies were performed at 8-week intervals. In the pediatric group, our results indicated a strong association between the self report of a common cold and a symptom exacerbation 4 weeks later (Odds ratio = 4.685; p = 0.001). In the adult group, we found no association between reports of common cold and tic exacerbations. Association with streptococcal infections could not be determined owing to the limited number of observed streptococcal infections. Thus, this study points to a hitherto unknown association of common viral infections with tic exacerbations in children, which may support the involvement of immune dysregulation in tic disorders.

Relative contribution of attention-deficit hyperactivity disorder, obsessive-compulsive disorder, and tic severity to social and behavioral problems in tic disorders

The aim of this study was to investigate social and behavioral problems related to attention-deficit hyperactivity disorder (ADHD), obsessions and compulsions, and tic severity in children with a tic disorder. Parents of 58 children with a tic disorder with and without different forms of ADHD completed the Child Behavior Checklist (CBCL) and the Children's Social Behavior Questionnaire. Patients with a tic disorder with primarily hyperactive-impulsive ADHD had the highest questionnaire scores, patients with primarily inattentive ADHD had medium scores, and patients without ADHD had the lowest scores. On most subscales, significant part correlations with ADHD severity, but not tic severity, were obtained. Severity of obsessions and compulsions was independently correlated with the CBCL Thought Problems subscale but not with most other subscales. There was no significant correlation between tic severity and ADHD severity. Thus, in patients with a tic disorder, the presence and severity of ADHD are the main predictors of associated behavioral and social problems.

Association of small life events with self reports of tic severity in pediatric and adult tic disorder patients: a prospective longitudinal study

BACKGROUND

Clinical experience suggests an association between stressful life events and fluctuations in symptom severity of tic disorder patients. The aim of the present study was to examine this possible relationship in a prospective longitudinal design.

METHOD

Two groups of patients with tic disorder according to the research criteria of the Tourette Syndrome Classification Study Group were included in this study (Sept. 2001 through March 2002): a pediatric group aged from 7 through 16 years (N = 25) and an adult group aged 18 years and older (N = 32). During a 12-week period, participants were asked weekly to fill out questionnaires regarding the occurrence of small life events and self ratings of tic severity.

RESULTS

Twenty-four of 25 patients in the pediatric group completed the study, and 28 of 32 patients in the adult group completed the study and reported at least 1 life event. In the adult group as a whole, we found a weak but statistically significant correlation between negative small life events and tic severity during the same week (r = 0.268, p <.001). However, only a minority of individual pediatric (21%) and adult (18%) patients demonstrated significant relationships between the frequency of small life events and tic severity in the same week or 1 week later (p </=.05), with undesirable small life events positively associated with tic severity in some patients and negatively associated with tic severity in other patients.

CONCLUSION

Contrary to traditional views, in general, life events do not account for changes in tic severity. Only in a minority of tic disorder patients do fluctuations in symptom severity appear to be associated with possibly stressful small life events.

Elevated D8/17 expression on B lymphocytes, a marker of rheumatic fever, measured with flow cytometry in tic disorder patients

OBJECTIVE

Elevated D8/17 expression on B lymphocytes is a known susceptibility marker of rheumatic fever. Previous studies have reported higher than usual D8/17 expression on B lymphocytes of patients with tic disorders. The purpose of this study was to assess D8/17 expression on B lymphocytes of tic disorder patients by using an objective method in which no operator variability was involved.

METHOD

D8/17 expression on B lymphocytes was assessed with flow cytometry by using an immunoglobulin M (IgM) monoclonal D8/17-specific antibody in an unselected group of Dutch patients with tic disorders (N=33) and healthy volunteers (N=20). Binding of this monoclonal antibody was compared with binding of an irrelevant IgM monoclonal antibody, and the shift in mean fluorescence intensity of the D8/17-specific antibody compared to that of the irrelevant IgM monoclonal antibody was used as a measure of D8/17 overexpression. For the patients, Yale Global Tic Severity Scale scores were used to assess disease severity.

RESULTS

D8/17 overexpression in the patient group (mean=16.8 arbitrary units, SD=30.5) was significantly higher than in the comparison group (mean=3.2, SD=3.0). A significant minority of the patients (N=13, 39.4%), however, had levels of D8/17 overexpression within the range of that of the healthy comparison subjects. Flow cytometric analysis did not indicate a separate subpopulation of D8/17-positive B cells.

CONCLUSIONS

These data confirm the utility of D8/17 B cell overexpression as a peripheral blood marker in patients with tic disorders and are compatible with a streptococcus-related pathogenesis for at least a subgroup of patients with tic disorders.

How unspecified are disorders of children with a pervasive developmental disorder not otherwise specified? A study of social problems in children with PDD-NOS and ADHD

This study examines possible differences and similarities between social behaviour problems in children with problems classified as pervasive developmental disorder not otherwise specified (PDD-NOS) and a group of children with problems classified as ADHD, as measured by parent questionnaires. The instruments involved were the CBCL (Child Behaviour Checklist), the ABC (Autism Behaviour Checklist) and a new instrument: the CSBQ (Children's Social Behaviour Questionnaire). In comparing the PDD-NOS group and the ADHD group, the results show that, according to parent reports, both groups have severe problems in executing appropriate social behaviour, but the PDD-NOS group can be distinguished from the ADHD group by the nature and the extent of these problems. The PDD-NOS group had significantly more social problems (as measured by the CBCL Social scale), withdrawn problems (as measured by the CBCL Withdrawn scale) and PDD-specific problems (as measured on the ABC Relating scale, the ABC Language scale, the CSBQ total score, the CSBQ Social Interaction scale and CBSQ Communication scale). In addition, although the descriptions of the social problems are global, i.e. on scale level, the results also show that the social problems of PDD-NOS children can be positively formulated and described as at least including severe social interaction problems, withdrawn behaviours and communication problems.