Until mid 2008, during a period of critical military surge and war zone injury, he was selected as the sole clinical psychologist providing treatment through the Deployment Health Center, NMCSD. Dr. Slier introduced and provided the individual and group, evidenced based, sleep and nightmare treatments, as well as group Cognitive Processing Therapy PTSD treatment. He was among the first, during this current war cycle, to address through clinical practice the impact of combat related, moral injury. Dr. Slier participated in the development of the first prototype of a combat PTSD residential program at NMCSD.