Current Pharmacologic Treatments in Impaired Social Interaction in Autism Spectrum Disorders
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Autism spectrum disorders (ASD) are neurodevelopmental disorders with
reduced cortical functional connectivity relating to social cognition. The evaluation of
pharmacological treatment in ASD has been directed at abnormal developmental
trajectories or toward enhancing plasticity during the development of brain.
Accumulating evidence indicates that the gross abnormalities in these neurotransmitter
systems such as serotonin and dopamine systems may underpin the neurophysiologic
mechanism of ASD. Particularly, the serotonergic system may be especially implicated
in pathophysiology of social impairment of ASD. Abnormal functional connectivity,
which affects the delivery of afferent signals, may be involved in the pathophysiology
of autism spectrum disorders (ASD). Arachidonic acid in the nervous system is
important in signal transduction related to neuronal maturation. Risperidone solution, a
novel antipsychotic which combined dopaminergic and serotonergic action, has shown
to be effective in impaired social interaction. Oxytocin may mediate the benefits of
positive social interaction and emotions. It is therefore worth noticing that risperidone
solution, intranasal administration of oxytocin, and dietary supplementation with
arachidonic acid have been found promising to maximize social interaction. Atypical
antipsychotics ariprazole and SSRI fluoxetine exhibited their efficacy in treating some
aspects of social relatedness or the core deficits of communication and socialization.
There is evidence that abnormalities exist in peptide systems such as neuropeptides.
GABAB antagonist STX209 has proved its efficacy in improving the ABC-irritability
and Social withdrawal subscales. D-cycloserine exhibited significant improvement on
social withdrawal subscale of the ABC in some subjects with ASD. It is hoped that
improved strategies for early identification with phenotypic characteristics and
biological markers (e.g., brain physiological and biochemical changes) would
remarkably improve the effectiveness of treatment.
The evaluation of treatments for ASD needs to be directed towards neurobiological
targets known to be important in the brain's response to abnormal developmental
trajectories or toward enhancing plasticity during the high sensitive period in
gene-environment interaction (epigenetic mechanism). Further research towards
neurobiology and effective treatments for ASD is required.
Autism spectrum disorders, impaired social interaction,
neurobiological bases, pharmacologic treatment, risperidone solution, arachidonic
Research Institute of Pervasive Developmental Disorders, Ashiya University Graduate School of Education, Hyogo 659-8511, Japan.