A 2017 review published in Frontiers in Neuroscience examines studies of postmortem brain tissue from patients with schizophrenia, bipolar disorder, and major depressive disorder, looking for evidence of impaired energy metabolism. Researchers identified 92 altered energy-related proteins in schizophrenia, 95 in bipolar disorder, and 41 in major depression. Five proteins were altered across all three conditions, including enzymes involved in glycolysis, the citric acid cycle, and mitochondrial ATP production.

These findings suggest that disturbances in cellular energy production may be a common biological feature of seemingly distinct psychiatric disorders. The review also highlights evidence of increased insulin resistance, abnormal glucose metabolism, and oxidative stress in patients with these conditions. Although the authors acknowledge that medication use may influence the postmortem findings and that it remains unclear whether metabolic dysfunction is a cause or consequence of psychiatric illness, the research strengthens the case for investigating mitochondrial dysfunction as a potential contributor to serious mental illness.

https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2017.00493/full