Sometimes the most serious wounds of war are the ones that can't be seen, only felt. My father served three Army combat tours in Vietnam. My brother, a Marine, has served in Iraq two times. I am acutely aware of how war can change a person. Those changes are happening right now.

Researchers at the San Francisco Veteran's Administration Hospital have found that 25 percent of America's Veterans coming home from war in Iraq and Afghanistan are suffering from some kind of mental health disorder. (Watch CNN's Jamie McIntyre's story) Post-Traumatic Stress Disorder is the most widespread problem, diagnosed in 13 percent of returning veterans, followed by anxiety, depression and substance abuse. PTSD can be extremely debilitating and may not surface until months or years after a war zone tour ends.

The average age of soldiers in Vietnam was 19 years old. The conflict in Iraq is also a war for the young, and according to the study, published in the Archives of Internal Medicine, veterans between 18 and 24 years old are at greatest risk for mental health disorders. Younger, lower-ranked service members are more likely to be on the frontlines and receive more combat exposure than their older counterparts.

Researchers say their findings signal a need for improvements in the prevention of military service-related mental health disorders. The Veterans Administration has come a long way in treating the mental wounds of war since the Vietnam era. My father received no help with mental issues after Vietnam, and he carried his war experience with him to his grave.

If you are a veteran and have questions about getting benefits for mental health issues, check out the Federal Benefits for Veterans and Dependents booklet at http://www1.va.gov/opa/feature/.