Main effect of the Early Start Denver Model (ESDM) intervention on developmental and symptom outcomes. Note. ADOS: Autism Diagnostic Observation Schedule, RRB: Restrictive and Repetitive Behavior, MSEL: Mullen Scales of Early Learning, DQ: Developmental Quotient, ELC: Early Learning Composite, MCDI: MacArthur Bates Communicative Development Inventory, VABS: Vineland Adaptive Behavior Scales, CSBS: Communication and Symbolic Behavior Scales, GDS: Griffith Developmental Scales, CARS: Childhood Autism Rating Scale; WASI FSIQ: Wechsler Abbreviated Scale of Intelligence Full Scale Intelligence Quotient, PDDBI: Pervasive Developmental Disorder Behavior Inventory. Note. Black boxes indicate the weight of each effect size and bars indicate the confidence interval. The overall effect size is indicated by the open diamond and dotted line (g = 0.357).