Participant liking of OROS-MPH/placebo will be assessed with the Drug Rating Questionnaire. This questionnaire is a derivative of the ARCI Benzedrine scales [Martin et al., 1971] to evaluate likeability and potential abuse based on the subjective response of the participant with ADHD. The Drug Rating Questionnaire is a visual analog scale that includes additional questions that assist in disentangling the therapeutic effects of the medication from the euphoria scales - an important confound as recently articulated by Kollins  in children with ADHD. There are no currently psychometrically validated scales available for such purposes in ADHD adults. The Drug Rating Questionnaire has been used successfully in clinical trials of adults with ADHD.