Recent Research on the Neuropsychiatric Aspects of Infectious Diseases

Since the beginning of the twentieth century, with the discovery of the spirochetal cause of syphilis, there has been evidence for the role of infectious agents in neuropsychiatric disorders. Organisms known to cause neuropsychiatric symptoms include the spirochetes Borrelia, Treponema and Leptospira, which can invade a patient's central nervous system. The role of Treponema pallidum in neurosyphilis was first documented in the early 1900's, while the neuropsychiatric aspects of Lyme disease (caused by Borrelia burgdorferi) were not discovered until much later, in the early 1960's and 1970's. Other organisms known to cause neurologic and psychiatric complications are viral, such as the human immunodeficiency virus (HIV, the causative agent of AIDS) and certain strains of influenza. In addition, there is evidence that numerous other viruses, such as rabies, rubella, Epstein-Barr virus, and other herpes viruses play a role in these types of disorders. This paper examines several infectious agents that are believed to cause neurologic or psychiatric problems and the current research that is being done in these areas. It also reviews some of the current research on chronic fatigue syndrome, a neuropsychiatric disorder for which the causative agent is yet unclear, and examines the possibility of an infectious etiology.