As described by the National Institute of Neurological Disorders and Stroke, mitochondrial myopathies are a group of neuromuscular diseases caused by damage to the mitochondria, small, energy-producing structures that serve as the cells’ power plants. Nerve cells in the brain and muscles require a great deal of energy, and thus appear to be particularly damaged when mitochondrial dysfunction occurs. Some of the more common mitochondrial myopathies include Kearns-Sayre syndrome, myoclonus epilepsy with ragged-red fibers, and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes. Most mitochondrial myopathies occur before the age of 20, and often begin with exercise intolerance or muscle weakness. Mitochondrial myopathies are quite rare. Therefore, experience and evidence are limited. Here is a talk on psychiatric disorders in people with mitochondrial diseases, including discussion of treatment.