Physical Problems can cause Mental Illness

The connection between physical ailments, such as viruses, and mental illness, is a topic I'm always interested in.

The January/February 2010 Scientific American Mind magazine has two short articles about this connection:

- An article about strep throat causing OCD like symptoms in children.  This is called "pediatric autoimmune neuropsychiatric disorders associated with strep," abbreviated PANDAS.  Now researchers have induced PANDAS in mice.

- An article about bodily inflammation (for example, from arthritis) causing greater memory loss in Alzheimer's patients compared to those without inflammation.  The memory loss is even worse if the patient also has an infection.  This might suggest that there is also an immune response going on in the brain, which causes mental problems.  

The article says that in healthy brains, this might just cause us to "feel under the weather"...... What about in Bipolar brains?  Perhaps viruses really do trigger depressive or manic episodes?