Profile Analysis of the Neurobehavioral and Psychiatric Symptoms Following Combat-Related Mild Traumatic Brain Injury: Identification of Subtypes.

Objective: To explore the taxonomy of combat-related mild traumatic brain injury (mTBI) based on symptom patterns.

Participants: Up to 1341 military personnel who experienced a combat-related mTBI within 2 years of evaluation.

Measures: Neurobehavioral Symptom Inventory and PTSD Checklist-Civilian Version (PCL-C).

Results: Cluster analysis revealed the following 4 subtypes: primarily psychiatric (posttraumatic stress disorder) group, a cognitive group, a mixed symptom group, and a good recovery group. The posttraumatic stress disorder cluster (21.9% of the sample) reported symptoms related to hyperarousal and dissociation/depression with few complaints related to cognition or headaches. The cognitive group (21.5% of the sample) had primarily cognitive and headache complaints with few mood symptoms. The mixed profile cluster included 18.6% of the sample and was characterized by a combination of mood complaints (hyperarousal and dissociation/depression), cognitive complaints, and headaches. The largest cluster (37.8% of the sample) had an overall low symptom profile and was labeled the "good recovery" group.

Conclusions: The results support a unique taxonomy for combat-related mTBI. The clinical differences among these subtypes indicate a need for unique treatment resources and programs.