White matter morphometric changes uniquely predict children's reading acquisition

This study examined whether variations in brain development between kindergarten and Grade 3 predicted individual differences in reading ability at Grade 3. Structural MRI measurements indicated that increases in the volume of two left temporo-parietal white matter clusters are unique predictors of reading outcomes above and beyond family history, socioeconomic status, and cognitive and preliteracy measures at baseline. Using diffusion MRI, we identified the left arcuate fasciculus and superior corona radiata as key fibers within the two clusters. Bias-free regression analyses using regions of interest from prior literature revealed that volume changes in temporo-parietal white matter, together with preliteracy measures, predicted 56% of the variance in reading outcomes. Our findings demonstrate the important contribution of developmental differences in areas of left dorsal white matter, often implicated in phonological processing, as a sensitive early biomarker for later reading abilities, and by extension, reading difficulties.

Internet-based, randomized, controlled trial of omega-3 fatty acids for hyperactivity in autism

OBJECTIVE

Preliminary evidence suggests that omega-3 fatty acids may reduce hyperactivity in children with autism spectrum disorder (ASD). We sought to examine the feasibility of a novel, Internet-based clinical trial design to evaluate the efficacy of this supplement.

METHOD

E-mail invitations were sent to parents of children aged 5 to 8 years enrolled in the Interactive Autism Network. All study procedures, including screening, informed consent, and collection of outcome measures took place over the Internet. The primary outcome measures were parent- and teacher-rated changes in hyperactivity on the Aberrant Behavior Checklist (ABC-H).

RESULTS

During the 6-week recruitment period, 57 children from 28 states satisfied all eligibility criteria and were randomly assigned to 1.3 grams of omega-3 fatty acids or an identical placebo daily for 6 weeks. Outcome assessments were obtained from all 57 participants and 57 teachers, and the study was completed in 3 months. Children in the omega-3 fatty acid group had a greater reduction in hyperactivity (-5.3 points) compared to the placebo group (-2.6 points), but the difference was not statistically significant (1.9-point greater improvement in the omega-3 group, 95% CI = -2.2 to 5.2). Adverse events were rare and not associated with omega-3 fatty acids. Participant feedback was positive.

CONCLUSION

Internet-based, randomized controlled trials of therapies in children with ASD are feasible and may lead to marked reductions in the time and cost of completing trials. A larger sample size is required to definitively determine the efficacy of omega-3 fatty acids. Clinical trial registration information-Omega-3 Fatty Acids for Hyperactivity Treatment in Autism Spectrum Disorder; http://clinicaltrials.gov; NCT01694667.

Biomarkers in autism

Autism spectrum disorders (ASDs) are complex, heterogeneous disorders caused by an interaction between genetic vulnerability and environmental factors. In an effort to better target the underlying roots of ASD for diagnosis and treatment, efforts to identify reliable biomarkers in genetics, neuroimaging, gene expression, and measures of the body's metabolism are growing. For this article, we review the published studies of potential biomarkers in autism and conclude that while there is increasing promise of finding biomarkers that can help us target treatment, there are none with enough evidence to support routine clinical use unless medical illness is suspected. Promising biomarkers include those for mitochondrial function, oxidative stress, and immune function. Genetic clusters are also suggesting the potential for useful biomarkers.

Autism traits in the RASopathies

BACKGROUND

Mutations in Ras/mitogen-activated protein kinase (Ras/MAPK) pathway genes lead to a class of disorders known as RASopathies, including neurofibromatosis type 1 (NF1), Noonan syndrome (NS), Costello syndrome (CS), and cardio-facio-cutaneous syndrome (CFC). Previous work has suggested potential genetic and phenotypic overlap between dysregulation of Ras/MAPK signalling and autism spectrum disorders (ASD). Although the literature offers conflicting evidence for association of NF1 and autism, there has been no systematic evaluation of autism traits in the RASopathies as a class to support a role for germline Ras/MAPK activation in ASDs.

METHODS

We examined the association of autism traits with NF1, NS, CS and CFC, comparing affected probands with unaffected sibling controls and subjects with idiopathic ASDs using the qualitative Social Communication Questionnaire (SCQ) and the quantitative Social Responsiveness Scale (SRS).

RESULTS

Each of the four major RASopathies showed evidence for increased qualitative and quantitative autism traits compared with sibling controls. Further, each RASopathy exhibited a distinct distribution of quantitative social impairment. Levels of social responsiveness show some evidence of correlation between sibling pairs, and autism-like impairment showed a male bias similar to idiopathic ASDs.

CONCLUSIONS

Higher prevalence and severity of autism traits in RASopathies compared to unaffected siblings suggests that dysregulation of Ras/MAPK signalling during development may be implicated in ASD risk. Evidence for sex bias and potential sibling correlation suggests that autism traits in the RASopathies share characteristics with autism traits in the general population and clinical ASD population and can shed light on idiopathic ASDs.

Considering biomedical/CAM treatments

Complementary and alternative medicine (CAM) is widely used to treat children with psychiatric disorders. In this review, MedLine was searched for various biomedical/CAM treatments in combination with the key words "childre", "adolescents", "psychiatric disorders", and "complementary alternative medicine". The biomedical/CAM treatments most thoroughly researched were omega-3 fatty acids, melatonin, and memantine. Those with the fewest published studies were N-acetylcysteine, vitamin B12, and oxytocin, although many biomedical/CAM treatments have no published studies. Although data are modest, there is evidence to suggest that biomedical/CAM treatments may be helpful for a subgroup of children with psychiatric disorders. Further research and more randomized, controlled trials in children are warranted.

Pharmacotherapy of inattention and ADHD in adolescents

This article reviews the current use of stimulants in adolescents. The evidence base for treatment of attention-deficit/hyperactivity disorder (ADHD) in adolescents is meager compared with that of ADHD in children, and much recent research of older populations with ADHD has been directed toward adults rather than adolescents. The structure of psychosocial treatment of ADHD differs across developmental ranges. For example, in children, treatment of ADHD uses direct behavior modification via parents and teachers. Treatment approaches then change toward contracting in adolescents (acknowledging the emerging independence common at this age) and toward self-management and coaching in adults. Medication for ADHD, however, does not substantially differ across developmental epochs. In supplementation of data, specifically on adolescence, much of our understanding of treating adolescents comes from upward or downward extension of the child and adult data. Symptomatic treatment (treatment for inattention, hyperactivity, or impulsive behavior) has always been a parallel approach to diagnostic and developmentally specific selection of treatment based on an incomplete literature. In recognition, this article assumes that inference from children or adults to adolescents, in the absence of adolescent-specific data, is commonplace and often confirmed with clinical experience. Such inferences, in the face of literature gaps, in no way obviate the need for continued research focused on adolescence.

Gene expression in blood is associated with risperidone response in children with autism spectrum disorders

Children with autism spectrum disorders (ASDs) often have severe behavioral problems. Not all children with these problems respond to atypical antipsychotic medications; therefore, we investigated whether peripheral blood gene expression before treatment with risperidone, an atypical antipsychotic, was associated with improvements in severe behavioral disturbances 8 weeks following risperidone treatment in 42 ASD subjects (age 112.7±51.2 months). Exon expression levels in blood before risperidone treatment were compared with pre-post risperidone change in Aberrant Behavior Checklist-Irritability (ABC-I) scores. Expression of exons within five genes was correlated with change in ABC-I scores across all risperidone-treated subjects: GBP6, RABL5, RNF213, NFKBID and RNF40 (α<0.001). RNF40 is located at 16p11.2, a region implicated in autism and schizophrenia. Thus, these genes expressed before treatment were associated with subsequent clinical response. Future studies will be needed to confirm these results and determine whether this expression profile is associated with risperidone response in other disorders, or alternative antipsychotic response within ASD.

A pilot randomized controlled trial of omega-3 fatty acids for autism spectrum disorder

We conducted a pilot randomized controlled trial to determine the feasibility and initial safety and efficacy of omega-3 fatty acids (1.3 g/day) for the treatment of hyperactivity in 27 children ages 3-8 with autism spectrum disorder (ASD). After 12 weeks, hyperactivity, as measured by the Aberrant Behavior Checklist, improved 2.7 (± 4.8) points in the omega-3 group compared to 0.3 (± 7.2) points in the placebo group (p = 0.40; effect size = 0.38). Correlations were found between decreases in five fatty acid levels and decreases in hyperactivity, and the treatment was well tolerated. Although this pilot study did not find a statistically significant benefit from omega-3 fatty acids, the small sample size does not rule out small to moderate beneficial effects.

Improving the prediction of response to therapy in autism

Autism is a heterogeneous disorder involving complex mechanisms and systems occurring at diverse times. Because an individual child with autism may have only a subset of all possible abnormalities at a specific time, it may be challenging to identify beneficial effects of an intervention in double-blind, randomized, controlled trials, which compare the mean responses to treatments. Beneficial effects in a small subset of children may be obscured by the lack of effect in the majority. We review the evidence for several potential model systems of biochemical abnormalities that may contribute to the etiology of autism, we describe potential biomarkers or treatment targets for each of these abnormalities, and we provide illustrative treatment trials using this methodology. Potential model systems include immune over and under reactivity, inflammation, oxidative stress, free fatty acid metabolism, mitochondrial dysfunction, and excitotoxicity. Including potential biomarkers and targeted treatments in clinical trials for autism provides a potential method for limiting the heterogeneity of enrolled subjects, which may improve the power of studies to identify beneficial effects of treatments while also improving the understanding of the disease.

Omega-3 fatty acids for autistic spectrum disorder: a systematic review

We conducted a systematic review to determine the safety and efficacy of omega-3 fatty acids for autistic spectrum disorder (ASD). Articles were identified by a search of MEDLINE, EMBASE, and the Cochrane Database using the terms autism or autistic and omega-3 fatty acids. The search identified 143 potential articles and six satisfied all inclusion criteria. One small randomized controlled trial (n = 13) noted non-significant improvements in hyperactivity and stereotypy. The remaining five studies were small (n = 30, 22, 19, 9, and 1) with four reporting improvements in a wide range of outcomes including language and learning skills, parental observations of general health and behavior, a clinician-administered symptom scale, and clinical observations of anxiety. Due to the limitations of evidence from uncontrolled studies and the presence of only one small randomized controlled trial, there is currently insufficient scientific evidence to determine if omega-3 fatty acids are safe or effective for ASD.

Anterior cingulate volume in pediatric bipolar disorder and autism

BACKGROUND

An increasing number of studies indicate the anterior cingulate gyrus (ACG) may play a role in the attention deficits associated with pediatric bipolar disorder (BD). Age, medications, and intelligence quotient (IQ) may affect ACG volume; few studies have controlled for these effects.

METHODS

We recruited 16 children with BD and 24 children with autism spectrum disorder (ASD); 15 children with no psychiatric diagnosis (NP) were also included. All participants were evaluated with the K-SADS and a DSM-IV Autism/Asperger's Checklist; the ADI-R was also administered to ASD participants shortly after the study began. The participants completed a brain MRI scan on a 1.5Tesla Signa GE scanner. We segmented the ACG and compared left and right ACG volumes between groups. The influence of medications on the ACG volume was assessed while controlling for the effects of age and IQ.

RESULTS

The left ACG volume was significantly smaller in the BD group compared to the NP (p=0.004) and ASD (p=0.006) groups. No significant differences were found in the right ACG volume. These differences do not appear to be attributable to medication use or IQ.

CONCLUSIONS

Pediatric BD patients have a smaller left ACG volume compared to NP children and children diagnosed with ASD. This replication and extension of previous studies suggest that the ACG volume abnormality may be a biomarker for BD.

Psychosis: atypical limbic epilepsy versus limbic hyperexcitability with onset at puberty?

Phencyclidine (PCP), ketamine (Special K), and MK-801 are noncompetitive N-methyl-d-aspartate (NMDA) antagonists that produce acute psychosis in humans. The psychosis produced by these psychomimetic drugs is indistinguishable from schizophrenia and includes both positive and negative symptoms. This drug-induced psychosis occurs after puberty in humans. On the basis of the MK-801-induced spike-and-wave activity in rats and increased blood flow and metabolism in brain of patients with psychosis caused by these psychomimetics, this brief review argues that this psychosis is an atypical form of limbic epilepsy. Moreover, there is a specific limbic thalamcortical psychosis circuit that mediates cell injury in limbic cortex of rodents and may mediate this PCP-induced psychosis in humans. It is proposed that this thalamocortical psychosis circuit develops at puberty and can mediate PCP and ketamine-mediated psychosis and possibly the psychosis of schizophrenia, bipolar disease and other disorders that have their onset at puberty. Finally, based on this developmentally regulated psychosis/epilepsy-related thalamocortical circuitry, it is proposed that antiepileptic drugs that promote GABAergic mechanisms may decrease the probability of episodic psychosis from any cause.

Caudate nucleus volume and cognitive performance: Are they related in childhood psychopathology?

BACKGROUND

Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability.

METHODS

Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed.

RESULTS

The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups.

CONCLUSIONS

Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group.

Neurodevelopmental pathways to aggression: a model to understand and target treatment in youth

The authors describe a neurodevelopmentally relevant, clinically derived model for understanding and treating aggressive behavior in youth. Based on case experience and literature review, the authors divide aggressive behavior into five symptomatic domains with respective neurobiological/neurodevelopmental underpinnings. These five symptom domains (impulsivity, affective instability, anxious/hyperarousal, cognitive disorganization, and predatory aggression) emerge as logical and clinically useful targets for treatment. The authors aim to establish a relationship between these symptom domains and brain structure and function that offers a clinically relevant approach to the complexities of understanding aggression and its treatment.

Integrated pharmacologic treatment of attention-deficit hyperactivity disorder (ADHD)

This article is a review of what is currently known about optimal treatments for patients with attention-deficit hyperactivity disorder (ADHD). It begins with a description of assessment techniques and the differential diagnosis, which includes learning disorders, anxiety disorders, and bipolar disorder. The high rate of comorbidity in patients with ADHD and the impact of comorbidity on treatment decisions are also discussed. Detailed descriptions of various pharmacologic treatments are provided, including a description of the role of combination pharmacotherapy and the integration of nonpharmacologic therapy. A decision-making model for selecting the most appropriate pharmacologic therapy versus combining pharmacotherapy with psychosocial interventions is described. The advantages and disadvantages of various pharmacologic agents--including long-acting stimulants and atomoxetine--are examined. Particular attention is paid to the recent Multimodal Treatment Study of Attention-Deficit Hyperactivity Disorder, sponsored by the National Institute of Mental Health, which includes a comparison of long-term pharmacotherapy, behavioral therapy, or a combination thereof, as well as an evaluation of the role of community-based therapy (i.e., treatment as usual). This article focuses on children and adolescents, because most of the research on ADHD has been conducted in this age group. However, a brief section on adults is also provided.

Review of neuroimaging studies of child and adolescent psychiatric disorders from the past 10 years

OBJECTIVES

To review recent neuroimaging studies of serious emotional disorders in youth and identify problems and promise of neuroimaging in clinical practice.

METHOD

Published reports from refereed journals are briefly described, critiqued, and synthesized into a summary of the findings to date.

RESULTS

Childhood-onset schizophrenia shows progressive ventricular enlargement, reduction in total brain and thalamus volume, changes in temporal lobe structures, and reductions in frontal metabolism. Autistic disorder is associated with cerebellar changes, greater total brain and lateral ventricle volume, and asymmetry. The prefrontal cortex and the basal ganglia are consistently reported as abnormal in attention-deficit/hyperactivity disorder. Patients with anorexia nervosa show enlarged CSF spaces and reductions in gray and white matter that are only partially reversible with weight recovery.

CONCLUSIONS

Results from neuroimaging studies of childhood-onset psychiatric disorders suggest consistency in the structures found to be abnormal, but inconsistencies in the nature of these abnormalities. Although neuroimaging technology holds great promise for neurodevelopmental research, it is not yet a diagnostic instrument.