Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

John Northup


Methylphenidate (MPH) has proven efficacy with the disruptive behaviors of children with ADHD in regular education settings (Gully and Northup, 1997; Northup et el., 1999; in press). Blum, Mauk, McComas, and Mace (1996) researched the separate and combined effects of behavioral and MPH treatments on the task engagement and disruptive behavior of 3 children with severe to profound mental retardation. This study used a single-subject, multielement or alternating treatment design to assess the separate and combined effects of MPH and behavioral treatments on the performance of 5 children with severe to profound mental retardation. MPH effects were evaluated within and across dosages. Data collected in 4 to 5 analog assessments (alone, escape, attention, tangible, control) determined the two classroom functional analysis conditions used in the subsequent medication evaluation. Target behavior rates (disruptive behavior and task engagement), care provider ratings of child behavior, and academic or task performance measures provided comparisons across 2 or 3 levels of MPH and placebo. Data from analog and classroom analyses were used to develop an appropriate, function-related behavioral treatment for each child that included differential reinforcement of appropriate behavior and graduated compliance. Results indicated that 3 children demonstrated decreased disruptive behaviors and improved task engagement in response to MPH while 2 children demonstrated similar improvement in response to the behavior intervention. Also, this study (a) determined the differential effects that stimulant medication may have on academic and behavioral performance both within and across dosages, (b) compared the effectiveness of stimulant medication and a function-related intervention in controlling problematic behavior, and (c) determined which medication dose, if any, was indicated for each participant. This study extends previous behavior pharmacological research by utilizing functional analysis of behavior disorders in relation to medication status and developmental task variables to assess the behavior mechanism of drug action in medication efficacy studies. Conclusions are interpreted in relation to the utility of functional analysis in identifying critical assessment parameters and selecting environmental stimuli useful in developing behavior treatments that maximize drug action.