RESUMEN
BACKGROUND: Cognitive impairments, negative symptoms, affective symptoms, and low energy are highly prevalent features of schizophrenia. Mitochondrial dysfunction has been hypothesized as one of the numerous factors to underlie the manifestation of these symptoms. The objective of this study was to evaluate whether Coenzyme Q10 (CoQ10) has a role in the treatment of schizophrenia and schizoaffective disorder. METHODS: A double-blind, randomized, placebo-controlled trial was conducted to assess the effects of CoQ10 supplementation (300 mg/day) on the co-primary outcomes of attention and working memory performance after 3 and 6 months. Secondary outcomes included plasma CoQ10 levels, mitochondrial function, energy, depression, anxiety, negative symptoms, and quality oflife. FINDINGS: In total, 72 patients were randomized to intervention groups. Overall, there was no effect of CoQ10 supplementation on the primary outcome measures at 3 or 6 months. Further, with the exception of plasma CoQ10 levels, CoQ10 supplementation also had no effect on the secondary outcomes. At 3 months, CoQ10 concentration was significantly higher in the CoQ10 group (3.85 µg/mL) compared with placebo (1.13 µg/mL); this difference was not present at 6 months. CONCLUSIONS: The results of the study suggest that CoQ10 supplementation at 300 mg/day for 6 months is unlikely to be beneficial for cognitive, psychological and health-related outcomes in schizophrenia and schizoaffective disorder. However, a number of limitations including low adherence, modest sample size, and attrition, likely reduce estimates of effects. As such, results should be considered preliminary.