Antidepressants are the most common medications prescribed to treat PTSD. Antidepressants make your brain release more serotonin and other 'feel good' chemicals that is in your brain's reward system. This is also released during things like eating your favorite food, Sexual relations, and exercise.
Examples of these are:
Zoloft
SSRI
Paxil
and much more...
I hope this helped. Have a great night!