It's a condition that's often called the invisible injury.
Post Traumatic Stress Disorder, or PTSD impacts people in different ways.
For war veterans, sometimes symptoms may not show up for months, or years after active duty.
A program called "Paws for Purple Hearts" is giving war vets a rewarding therapy program.
The PTSD patients are training the animals to later become guide dogs for disabled veterans.
If you'd like to learn more about the program, click on the related link to this story.
