“The DSM-5 Neurodevelopmental Work Group spent a great deal of time evaluating the reliability and validity of the separate DSM-IV diagnoses and concluded that there was no evidence to support continued separation of the diagnoses,” Susan Swedo, M.D., chair of the Work Group on Neurodevelopmental Disorders, told Psychiatric News.
The new criteria describe “deficits in social communication and social interaction” and “restrictive and repetitive behavior patterns”—the two principal symptoms associated with ASD—along with an expanded number of specifiers. The latter can be used by clinicians to specify features of the disorder with which some individual patients may present, such as if the autism is accompanied by intellectual impairment or is associated with a known genetic/medical or environmental/acquired condition.
In addition, the criteria include three levels of severity for both principal symptoms to indicate the level of supportive services required by an individual patient. The three levels are “requiring support,” “requiring substantial support,” and “requiring very substantial support.”
For instance, for the symptom of “deficits in social communication and social interaction,” a patient requiring “very substantial support” would be one who has “severe impairments in functioning, very limited initiation of social interactions, and minimal response to social overtures from others.” Similarly, for “repetitive/restrictive behaviors” a patient requiring very substantial support would be one who exhibits inflexibility of behavior and extreme difficulty coping with change, as well as “great distress/difficulty changing focus or action.”
Swedo noted also that the DSM-5 criteria indicate that symptoms must be present in the “early developmental period,” reflecting research that has shown the disorder is evident as early as age 24 months.