Causes of Mental Disorders - Disease, Injury and Infection

Disease, Injury and Infection

Higher rates of mood, psychotic, and substance abuse disorders have been found following traumatic brain injury (TBI). Findings on the relationship between TBI severity and prevalence of subsequent psychiatric disorders have been inconsistent, and occurrence has been linked to prior mental health problems as well as direct neurophysiological effects, in a complex interaction with personality and attitude and social influences.

A number of psychiatric disorders have often been tentatively linked with microbial pathogens, particularly viruses; however while there have been some suggestions of links from animal studies, and some inconsistent evidence for infectious and immune mechanisms (including prenatally) in some human disorders, infectious disease models in psychiatry are reported to have not yet shown significant promise except in isolated cases.

There have been some inconsistent findings of links between infection by the parasite Toxoplasma gondii and human mental disorders such as schizophrenia, with the direction of causality unclear. A number of diseases of the white matter can cause symptoms of mental disorder.

A mother's exposure to viruses or toxic chemicals while pregnant may also contribute to a child's mental disorder.

Poorer general health has been found among individuals with severe mental illnesses, thought to be due to direct and indirect factors including diet, bacterial infections, substance use, exercise levels, effects of medications, socioeconomic disadvantages, lowered help-seeking or treatment adherence, or poorer healthcare provision. Some chronic general medical conditions have been linked to some aspects of mental disorder, such as AIDS-related psychosis.

The current research on Lyme's disease caused by a deer tick, and related toxins, is expanding the link between bacterial infections and mental illness.

http://www.nlm.nih.gov/medlineplus/mentaldisorders.html