Sleep problems as possible predictors of intensified symptoms of autism $ Kimberly A. Schreck a,* , James A. Mulick b , Angela F. Smith a a Psychology Program, Penn State University-Harrisburg, 777 W. Harrisburg Pike, Middletown, PA 17057, USA b Columbus Children’s Hospital, The Ohio State University, USA Received 25 April 2002; received in revised form 7 February 2003; accepted 8 April 2003 Abstract Researchers have been placing an increased importance on discovering what vari- ables contribute to better prognosis during behavioral interventions for children with autism. This article preliminarily identifies sleep problems that may exacerbate symp- toms of autism; thus, possibly influencing effectiveness of daytime interventions. A data- base of parent report of sleep problems of children with autism (N ¼ 55), ranging from 5 to 12 years of age (M ¼ 8:2 years) was evaluated. Results suggested that fewer hours of sleep per night predicted overall autism scores and social skills deficits. Similarly, stereotypic behavior was predicted by fewer hours of sleep per night and screaming during the night. Increased sensitivity to environmental stimuli in the bedroom and screaming at night predicted communication problems. Finally, sensitivity to environ- mental stimuli in the bedroom also predicted fewer developmental sequence distur- bances. The results indicate that sleep problems and the diagnostic characteristics of autism may be related. However, future research must be completed to determine the specific relationship. # 2004 Elsevier Ltd. All rights reserved. Keywords: autism; environmental stimuli; communication problems Research in Developmental Disabilities 25 (2004) 57–66 0891-4222/$ – see front matter # 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ridd.2003.04.007 $ A portion of the data reported in this paper was submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at The Ohio State University by the first author. * Corresponding author. Tel.: þ1-717-948-6048; fax: þ1-717-948-6519. E-mail address: kas24@psu.edu (K.A. Schreck).