trying to get to sleep and sometimes these nightmares won't let me go to sleep. >> narrator: charles mcduffieeen in rehab for a month. he is having nightmares about vietnam. >> feel real. i wake up sweating and one day everything were wet-- pillow case, sheet and everything. >> mr. mcduffie suffers not only from the disease of addiction, he also has some post-traumatic stress issues stemming from his service during vietnam. according to him he had 19 confirmed kills but one, that as he says, his friend that he brought back with him that he still has dreams about, nightmares. >> narrator: the treatment facility has arranged for mcduffie to have therapy for post-traumatic stress. >> mcduffie family. >> hey mcduffie. >> i went to vietnam when i was 19 years old, came back when i was 23. i knew something was wrong with me, definitely, but i didn't know what it was, you know. i got a lot of dark memories about vietnam. a little incident happened that i can't get over. (indistinct radio chatter) i killed a vietcong that didn't have a weapon. i shot that man about 30 times. i could see that little m