Among the younger siblings of children with autism who do not have the disorder themselves, more than one-quarter show developmental delays at their first birthday, according to a study published in April.

The equivalent of one-tenth of a single pill of the anxiety drug clonazepam alleviates many autism-like behaviors in a mouse model of the disorder, according to a study published 19 March in Neuron.

Children of women who have attention deficit hyperactivity disorder are at increased risk for autism and attention deficit, according to a study published 21 January in the Journal of Child Psychology and Psychiatry. This suggests the two diseases have common risk factors.

Deleting the Rett syndrome gene MeCP2 from oligodendrocytes, a brain support cell, leads to a mild form of the disorder in mice, according to a study published 27 November in The Journal of Neuroscience.

Children with autism who have constipation are often also plagued by compulsive or repetitive behaviors, a core feature of autism, finds a study published 29 November in the Journal of Autism and Developmental Disorders.

Intelligence quotients of toddlers with autism closely predict how they will fare as adults, reports a 17-year study published 9 December in the Journal of Child Psychology and Psychiatry.

Mice with a duplication of SHANK3, a gene with strong links to autism, are hyperactive and manic, reports a study published 7 November in Nature.
 

Lithium and other drugs that inhibit a key enzyme called GSK-3 reverse cognitive deficits in a mouse model of fragile X syndrome, according to a pair of studies published in August and September. 

A newly discovered spontaneous mutation, described 27 August in Molecular Psychiatry, links autism to changes in the regulation of the chemical messenger dopamine.

Clinicians should place children under age 5 who have developmental delay into a broad diagnostic category, called ESSENCE, which may then resolve into any number of individual diagnoses over time, says Christopher Gillberg.