Factor structure of the restricted academic situation scale: implications for ADHD.

Background: To study the factor structure of the Restricted Academic Situation Scale (RASS), a psychometric tool used to assess behavior in children with ADHD, 117 boys and 21 girls meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria for ADHD and aged between 6 and 12 years were recruited. Assessments were carried out before and 65 min after the administration of either a placebo or 0.25 mg/kg of methylphenidate. Placebo and methylphenidate were each administered according to a double-blind placebo-controlled crossover design. Results: Principal component analysis, followed by a confirmatory maximum likelihood factor analysis, revealed two main factors for the RASS, task disengagement (TD) and motor activation (MA). Only TD was inversely correlated with age, indicating that TD and MA may be differentially modulated during development. Conclusions: MA and TD are distinct traits of ADHD. It may be important to consider them separately when conducting studies on ADHD. (J....