Coenzyme-Q10 (CoQ10) is an essential cofactor in the mitochondrial electron-transport-chain in addition to being a potent lipophilic antioxidant. Deficits in CoQ10 status have been linked to cardiovascular disease, cognitive decline, fatigue, and depression. CoQ10 supplementation may have a potential therapeutic value for patients with schizophrenia and schizoaffective disorder. This is a double-blind, placebo-controlled, randomised trial that will compare neurocognitive performance and symptoms of schizophrenia and schizoaffective disorder in participants randomised to active CoQ10 compared to scores from participants who received placebo. CoQ10 will be administered at a dose of 300mg/day, delivered in 3 doses of 100mg each. Participants will take CoQ10/placebo for 6 months. At three time points (baseline, 3 months and 6 months) each participant completes a neurocognitive and psychological battery of assessments. Blood pressure is monitored, and blood samples to assess mitochondrial function and plasma CoQ10 status are taken at each assessment.
