this might have a direct connection to vashti's thread on therapy.
from Wiki:
Persons with a higher IQ have generally lower adult morbidity and mortality. Post-Traumatic Stress Disorder, severe depression and schizophrenia are less prevalent in higher IQ bands.
A decrease in IQ has also been shown as an early predictor of late-onset Alzheimer's Disease and other forms of dementia.
In terms of the effect of one's intelligence on health, high childhood IQ correlates with one's chance of becoming a vegetarian in adulthood, and inversely correlates with the chances of smoking, becoming obese, and having serious traumatic accidents in adulthood.