This review highlights several methodological challenges involved in research on aging, health, and mortality in adults with rare intellectual disability syndromes. Few studies have been performed in this area, with research obstacles that include: the ascertainment of older adults with genetic versus clinical diagnoses; likelihood that adults…

Similar to the state of the broader intellectual disabilities field, many gaps exist in the research and treatment of mental health concerns in people with Down syndrome. This review summarizes key findings on the type and prevalence of behavior and emotional problems in children, adolescents, and adults with Down syndrome. Such findings include…

As researchers have examined the so-called "behavioral phenotypes" of different genetic mental retardation conditions, the measurement of behavior becomes increasingly important. From earlier, more global examinations of noteworthy behaviors or profiles, recent researchers have moved from reliance on a single, all-encompassing questionnaire to…

New insights into biological factors that underlie autism may be gained by comparing autism to other neurodevelopmental disorders that have autistic features and relatively well-delineated genetic etiologies or neurobiological findings. This review moves beyond global diagnoses of autism and instead uses an endophenotypic approach to compare…