Our study is the first to compare in referred and population-based samples the co-occurrence of four common problems for which children are referred for psychological evaluations (ADHD, autism, oppositional defiant disorder/ODD, and academic impairment). Youth were rated by their mothers on the Pediatric Behavior Scale, assessing symptoms of ADHD, autism, ODD, and academic impairment. The 1,601 referred children (6-16 years) were diagnosed with autism and/or ADHD. The population-based samples…
