Science Update
February 6, 2007
Autism Research Efforts Highlighted in Biological Psychiatry Special Issue
The February 15, 2007 special issue of Biological Psychiatry is dedicated to recent advances in autism research, including many studies funded by the Institute. As described in an editorial by NIMH scientists Benedetto Vitiello, M.D., and Ann Wagner, Ph.D., the articles in this issue cover a wide range of topics related to autism, including potential treatments, growth and functioning of the brain, deficits in cognitive skills, and new research tools. Important new information presented by some of the papers includes:
- Many studies suggest a link between autism and the hormone oxytocin, which helps regulate social attachment behaviors, such as mother-infant bonding, nursing, separation distress, and sexual behaviors. Based on this finding, researchers led by Eric Hollander, MD, Mount Sinai School of Medicine, studied the effects of intravenous oxytocin on adults diagnosed with autism or a related illness, Asperger’s disorder, both of which are commonly associated with impaired social functioning. All 15 participants in the study, partially funded by NIMH, improved in their ability to identify emotional moods conveyed in speech, assessed by listening to a tape-recorded sentence of neutral content, such as “The game ended at 4 o’clock,” read in a happy, indifferent, angry, or sad tone. The researchers suggested that oxytocin might be useful in treating or reducing social deficits related to autism.
- Researchers funded by NIMH and the National Institute on Child and Human Development (NICHD) and led by Geraldine Dawson, PhD, University of Washington, found that rapid and excessive growth in head size during the first 12 months of a child’s life may precede and then overlap with the onset of behavioral symptoms related to autism. After 12 months, slower head growth relative to the rate of increase during the first year seems to coincide with worsening of symptoms. Such findings on the early signs of autism may be useful in identifying children at a very young age who may benefit from interventions to lessen the decline in functioning due to autism, or possibly even to change the course of the illness.
- A group of Canadian researchers led by Rob Nicolson, MD, University of Western Ontario, studied brain functioning in young boys with autism, compared with young boys without autism, using proton magnetic resonance spectroscopic imaging (MRSI). The researchers observed abnormal metabolic activities within the brain, such as reductions in glutamate and/or its precursor glutamine in cerebral gray matter of participants with autism. This finding suggests that widespread dysfunction in brain systems involving glutamate, a neurotransmitter with many important roles in the proper growth and functioning of brain cells, may affect early brain development and may be related to autism.
- Beatriz Luna, Ph.D., University of Pittsburgh, and colleagues examined the development of cognitive abilities from late childhood through early adulthood in participants with autism but without mental retardation. Their study, funded by NIMH and NICHD, uncovered deficits across all ages in tasks that required working memory and voluntary response inhibition—the ability to choose a task-appropriate response and prevent inappropriate responses. However, signs of developmental progression suggest that interventions and treatments may continue to enhance cognitive functioning and behavioral abilities through adolescence and early adulthood.
- Children with autism and other pervasive developmental disorders (PDD) may show a wide range of impairments that are difficult to measure and to track over time, which is particularly important in research studies aiming to find effective treatments. With the need for dependable and sensitive measurement tools, Ann Wagner, PhD, Chief of the Neurodevelopmental Disorders Branch at NIMH, and colleagues developed the Developmental Disability-Child Global Assessment Scale (DD-CGAS). This modified version of the CGAS, commonly used to rate functioning in children, better reflects characteristics of children affected by developmental disorders. After testing use of the DD-CGAS among doctors and against other similar measurement tools, the researchers found the new scale provides reliable and stable assessments of functioning and may be useful in treatment studies.
Reference
Vitiello B, Wagner A. The rapidly expanding field of autism research. Biol Psychiatry. 2007 Feb 15;61(4):427-8.
