Markers for improvement in children with pervasive developmental disorders

ABSTRACT. In a series of prevalence and follow‐up studies on North Dakota's 59 children with pervasive developmental disorders, the patient characteristics of hyperlexia, Tourette disorder (TD), and the absence of seizures were found to be associated with improved outcome or higher IQ. We entered these and 17 other characteristics into a regression model using forward, step‐wise inclusion to identify the smallest set of predictor variables which were significantly associated with the dependent variables of IQ, and receptive and expressive language. Of the 20 predictor variables used in the regression analysis, the same four variables met inclusion criteria for each of the dependent variables. These predictor variables were: hyperlexia, a known aetiology, TD and age. The relevance of these findings is discussed.