Across the lifespan, autistic individuals experience symptomatology concomitant with their diagnosis including increased rates of daytime behavior (e.g. stereotypy, self-injurious behavior, and aggression) and psychopathology (e.g. attention deficit hyperactivity disorder, anxiety, and depression). In addition to this inter-related behavior and psychopathology, autistic children, adolescents, and adults consistently exhibit a wide variety of sleep problems (e.g. insomnia, reduced total sleep time, increased sleep onset latency, night waking, etc.). Early research and current research continue to describe the inter-relatedness among these daytime behaviors, psychopathology, and sleep problems for autistic individuals. Although descriptions of these issues appear in research, only preliminary suggestions exist for the causes and contributors toward the sleep problems or the interactions of sleep problems with psychopathology, although current research suggests a possible biopsychosocial interaction.