This project focuses on assessing efficacy of off-label use of adjunctive methylphenidate ER 36 mg among 24 stable inpatients with schizophrenia spectrum illness. This is a single centre study at the Royal Ottawa Mental Health Centre, Ottawa, Canada. An open-label fixed dose controlled cross-over trial is planned. Individuals with schizophrenia who are stable on antipsychotic medications will be invited to participate in the study. Participants will be randomized into receiving four weeks of methylphenidate extended release (ER) 36 mg or treatment as usual and will switch group assignments for another 4 weeks. The duration of the study is 12 weeks for each participant, including 8 weeks of treatment (4 weeks treatment as usual and 4 weeks treatment as usual + adjunctive methylphenidate ER) and a follow-up visit at 12 weeks (study end point). A number of standardized scales will be used to measure functional capacity, cognition and symptom severity.
Two of the major features of schizophrenia spectrum illness, negative and cognitive symptoms, have been associated with poor functional outcome and burden of illness. Given the proposed role of dopaminergic hypoactivity, augmentation with psychostimulants has been postulated as one of the potential treatment options for negative and/or cognitive symptoms of schizophrenia. The major drawback for use of these agents is a potential risk of relapse or worsening of psychosis through direct or indirect dopamine agonism activity and a great deal of caution has been called for use of stimulants in individuals with psychosis. However, preliminary results of earlier studies indicated improvement of negative and cognitive symptoms with off-label use of adjunctive psychostimulants. The present study aims to assess off-label use of adjunct psychostimulants in patients with schizophrenia in a tertiary mental health centre, focusing on efficacy and safety.