Background: Mitochondrial diseases are among the most common genetic disorders, and they have been associated with several psychiatric syndromes.
Method: The authors present two cases of obsessive-compulsive disorder (OCD) occurring in patients with MELAS (the A3243G mutation).
Results: Their clinical course and response to standard OCD treatment strategies was poor.
Discussion: Possible mechanisms for OCD symptoms are suggested by animal models and neuropathological findings. It remains unclear whether different types of mitochondrial disorders are associated with particular neuropsychiatric symptoms. Psychiatric symptoms may predate the diagnosis of mitochondrial disorder; thus, psychiatrists should consider mitochondrial disorders in the presence of common physical signs that are typically associated with these disorders.