Mental illness causes being discovered

WASHINGTON, Nov. 15 (UPI) -- One in 17 Americans has a mental illness, such as schizophrenia, major depression or bipolar disorder, U.S. researchers say.

However, science is only beginning to understand the underlying physical causes of mental illness.

A series of findings were presented at the Neuroscience 2011, the Society for Neuroscience's annual meeting that include:

-- Childhood anxiety and depression alter the way the amygdala -- the part of the brain that processes and remembers emotional reactions -- connects to other regions of the brain. The findings might help explain how early-life stress can lead to future emotional and behavioral issues.

-- In animal studies, a link was found between two factors associated with schizophrenia, prenatal infection and impaired function of a molecule important in memory.

-- Researchers identified a brain chemical important to antidepressant response in mice. The findings might help in the design of therapies for major depression.

-- The connections between two specific areas of the brain might contribute to depression. Stimulating these circuits in rats had an antidepressant effect.