Mitochondria are tiny structures inside nearly every cell in your body. Often called the “powerhouses” of the cell, their main job is to convert the food you eat into usable energy (ATP). Your brain is especially dependent on this energy—although it makes up only about 2% of body weight, it uses roughly 20% of the body’s total energy supply.
When mitochondria become damaged or impaired, they produce less energy and more harmful byproducts. This can happen through chronic inflammation, oxidative stress, insulin resistance, nutrient deficiencies, certain medications, toxins, or the effects of long-standing mental health conditions themselves. Over time, these stressed mitochondria struggle to keep up with the brain’s high energy demands.
Impaired mitochondrial function disrupts brain energy metabolism. Neurons may not fire as efficiently, communication between brain regions can slow, and the brain becomes less resilient to stress. This energy shortfall is increasingly recognized as a contributing factor in many psychiatric and neurological conditions.
People with impaired brain energy metabolism often experience a cluster of symptoms that go beyond typical mood complaints. These can include persistent mental fatigue, brain fog, difficulty concentrating, slowed thinking, reduced motivation, emotional instability, heightened sensitivity to stress, and a sense that the brain is “running on empty.” In more severe cases, these energy problems may contribute to treatment-resistant depression, bipolar symptoms, or cognitive difficulties.
Understanding the role of mitochondria helps explain why approaches that support cellular energy—such as therapeutic nutritional ketosis—are being studied as ways to improve mental health from the ground up.
