Add-On Pramipexole for the Treatment of Schizophrenia and Schizoaffective Disorder: A Randomized Controlled Trial

Several small clinical trials have reported that the dopamine agonist pramipexole was beneficial in treating patients with schizophrenia. A confirmatory trial was conducted to test this hypothesis.

This 16-week, multicenter, double-blind, randomized, placebo-controlled study included 200 subjects meeting DSM-IV-TR criteria for schizophrenia or schizoaffective disorder. Patients were randomized to receive either pramipexole (0.75 mg twice daily, n = 100) or placebo (n = 100) as an add-on to their regular antipsychotic treatment. The primary outcome measure was the total score on the Positive and Negative Syndrome Scale (PANSS); secondary outcome measures included PANSS subscale and cognitive functioning scores. Recruitment was performed in 30 sites in Romania and 1 site in the Republic of Moldova between January and June 2011.

Analysis of covariance models showed no significant difference between pramipexole and placebo for total PANSS (P > .99) and PANSS positive (P > .99), negative (P = .73), and general psychopathology (P = .99) subscale scores. Changes in Clinical Global Impressions-Severity of Illness scale and Brief Assessment of Cognition in Schizophrenia scores showed no significant difference between pramipexole and placebo.

The results of this large randomized controlled trial indicated that pramipexole was not efficacious as an add-on to antipsychotic medications for schizophrenia.

ClinicalTrials.gov identifier NCT01320982.