The repetitive behaviour questionnaire (RBQ) (Turner, 1995) is one of the three most commonly used interview/questionnaire measures of repetitive behaviour (Honey et al., in preparation). Despite this there is a scarcity of information concerning its structure, reliability and validity. The psychometric properties of the RBQ were examined when…

Challenging behaviors are common and persistent in persons with autism spectrum disorders (ASDs). Best practices dictate that symptoms of ASD and these co-occurring problems be identified and then treated at the earliest possible age. Having said this, there has been a dearth of available assessment methods to make sure identifications in infants…

Diagnosing autism and PDD-NOS at very early ages has become a major priority in the field of mental health. More recently, researchers have also come to realize the importance of identifying co-occurring conditions of psychopathology in this population. In the present study, 309 children between 17 and 37 months of age who had been identified as…