Abstract
This study explored the relationship between whole blood serotonin, irritability, anger, and aggression among military personnel deployed in support of combat operations in Iraq or Afghanistan. The participants were active duty military personnel with at least one deployment to Iraq or Afghanistan. After obtaining the prospective participant's consent, the investigators administered the Anger, Irritability, and Assault Questionnaire, the Post-Trauma Exposure Questionnaire, and drew the post-deployment whole blood serotonin specimen. For purposes of comparison, a pre-combat whole blood serotonin sample was obtained from an aliquot stored at the Department of Defense Serum Repository. Seventeen military subjects met the full inclusion criteria to participate in this pilot study. Participants with normal whole blood serotonin levels had significantly lower scores on the Anger, Irritability, and Assault Questionnaire than subjects who were considered to have either low or high whole blood serotonin. The findings from this study tentatively suggest that any abnormal whole blood serotonin level contributes to some form of behavioral irritability.