The Emerging Neuroscience of Autism: an Opportunity to Learn and to Share
Autism is a complex disorder. Answers will be found by taking multi-disciplinary approaches. A broad vision of autism spectrum disorder (ASD) considers how the brain develops and affects cognition, what treatments work for core symptoms, and how ASD changes over the lifespan. However, opportunities for scientists to appreciate the broad vision and diversity of approaches are unfortunately few.
This year a special 2-day conference on autism was held prior to the annual Society for Neuroscience meeting in San Diego, giving scientists an opportunity to focus on ASD and share ideas. The conference, called The Emerging Neuroscience of Autism Spectrum Disorders: Etiologic Insights; Treatment Opportunities, offered an overview of current autism research from many of the world’s leading autism researchers.
There were two strong themes in the meeting. The first was that autism research has historically studied different groups of children at specific time points. This kind of study is known as cross-sectional research. There has been comparatively little research on how children change over time, known as longitudinal research. Given that ASD is a developmental disorder which changes over the lifespan, more longitudinal research is needed. The second theme highlighted what we can learn from the incredible diversity of symptom and subtypes of ASD. Future ASD research demands a greater focus on individual differences instead of the common comparisons between averages derived from groups of individuals with ASD and typically-developed individuals.
The first session of the meeting included a review of what is known about autism risk genes. Steve Scherer, M.D. (University of Toronto) described how small variations in the number of copies of a piece of genetic code (copy number variations, CNVs) can be risk factors for ASD. These CNVs may be inherited or occur for the first time in the individual with ASD (de novo). Similar CNVs have also been identified in ADHD, schizophrenia and bipolar disorder, suggesting that there may be some common pathways underlying related developmental and psychiatric disorders. The incredible advances in genetic research, in no small part from Dr. Scherer and the Autism Genome Project, enable scientists to explore how these genetic variations affect brain development in animal models and provide clues into the underlying biology of ASD.
Declan Murphy, M.D. (Institute of Psychiatry, UK) impressed the audience with his proposal that brain imaging could be used to assist future clinicians in the diagnosis of ASD. The high costs of diagnosing individuals with ASD in Dr. Murphy’s South London community clinic motivated him to explore new methods. He used statistical methods combined with functional brain imaging to identify brain networks that may be different in adults with ASD. The use of brain scans may one day make the diagnosing ASD cheaper, quicker and potentially more accurate.
Cognition and new treatments
Day 2 of the meeting shifted focus away from biology to cognitive development and the evaluation of behavioral interventions. Tony Charman, Ph.D., (Institute of Education, London) described his study of cognitive strengths and weaknesses in a large sample of children with ASD. He argued for the importance of understanding the unique pattern of cognitive skills found in ASD to guide neuroimaging research and developing assessments of skills for early intervention programs. Dr. Charman also identified challenges in this area of research, noting that the field must address issues, such as small sample sizes and reliance on group comparisons if we are to progress.
Cathy Lord, Ph.D., (University of Michigan) showed longitudinal data collected using the Autism Diagnostic Observation Schedule (ADOS)—a tool to identify and quantify features of ASD. Her data revealed individual differences in the development of particular skills, such as eye contact, and joint attention skills, even though overall ADOS scores remain mostly constant. Language IQ remains an important predictor of children’s expected progress. Perhaps in the future, the ADOS diagnostic tool can also be used to monitor the long-term benefits of interventions.
The final two sessions focused on interventions. Fred Frankel, Ph.D. (UCLA) presented data from new interventions in friendship training. Judith Reaven, Ph.D., (University of Colorado School of Medicine) showed her data on cognitive behavioral therapy for anxiety in ASD. Aubyn Stahmer, Ph.D., (Rady Children’s Hospital, San Diego) evaluated the use of an integrated intervention model in community settings. Sally Rogers, Ph.D. (MIND Institute) concluded this session with a summary of the challenges in developing good outcome measures for intervention studies.
The last session summarized the evidence behind pharmacological treatments for ASD. One of the real challenges for behavioral pharmacologists is how to identify drug treatments for core social and communication skills. Currently only two drugs are approved for treating irritability in ASD. Several other drug treatments have been tested in clinical trials with minimal or no evidence for their effectiveness. Individual differences and variation in symptoms over time make finding treatments for the core symptoms of ASD like trying to hit a moving target.
Putting it all together
David Amaral, Ph.D. of the MIND Institute and current president of the International Society for Autism Research, summarized the meeting by focusing on autism research ‘Promises and Pitfalls’. On the positive side, he noted a dramatic rise in research, supported by increases in public and private funding, such as the major contribution by Autism Speaks. As for pitfalls, Dr. Amaral underscored the significant variability among individuals with autism that must be recognized if research results are to be meaningful. He also encouraged the continuation of brain research across the lifespan acknowledging age-related changes in brain development and behavior over time.
Progress in the field of brain research will require an on-going partnership among people with autism, families and researchers. We are both optimistic about progress and impatient to find answers. We all look forward to IMFAR 2011 in May when autism researchers return to San Diego with a broader perspective and new insights.