Objective: This purpose of this study was to determine the incidence and types of preexisting mental disorders among military personnel who received mental health services in an Iraqi war zone.
Methods: The study examined psychiatric histories of 1,078 American military personnel (Marines, 65%; Army, 23%; Navy, 11%; and Air Force, <1%) deployed to Iraq and seen by in-theater mental health providers between January 2006 and February 2007.
Results: Among the 1,078 patients, the most frequent in-theater diagnoses were anxiety (24%), adjustment (23%), and mood (19%) disorders. Twenty-nine percent of the sample (N=308) had a psychiatric diagnosis in their medical records before their first encounter with mental health services in Iraq (Navy patients, 42%; Army patients, 39%; and Marine Corps patients, 23%). The mean time between last predeployment diagnosis and first in-theater mental health encounter was 21 months. For patients with a prior diagnosis, the highest rate of relapse (receipt of the same diagnosis in theater) was for attention-deficit hyperactivity disorder (57%), followed by anxiety disorders (44%)--especially posttraumatic stress disorder (PTSD) (55%)--mood disorders (38%), and adjustment disorders (32%).
Conclusions: A significant proportion of military personnel who experienced mental health problems in a combat zone had preexisting psychiatric conditions. Because more than half of predeployment diagnoses were received in the nine months before the in-theater mental health encounter, further study may be advisable to determine whether a time-based algorithm for deployability is needed, particularly for PTSD, for which a high rate of repeat diagnosis in theater was found.