Inclusion Criteria:

• 1. Male and female Veterans who deployed to combat zones since 9/11.
• 2. Currently meets criteria for full or subthreshold PTSD, determined by the Clinician-Administered PTSD Scale for DSM-5
• 3. Engaged in at least 3 self-reported aggressive acts (e.g., yelling, throwing objects, hitting objects/people) in the last month, measured by the Overt Aggression Scale
• 4. Impulsive aggression is his/her primary form of aggression, determined by the Impulsive Premeditated Aggression Scale
• 5. Each Veteran must allow an independent aggression rater (live-in partner, family member, or roommate above 18 years of age)\] verify the number of aggressive acts, using the Overt Aggression Scale.
• 6. Agreement not to change psychotropic medications through the duration of the study.

Exclusion Criteria:

• 1. Currently suicidal with intent of self-harm in the last week.
• 2. Currently homicidal with plans to hurt a specific person.
• 3. Unable to complete self-report measures.
• 4. Meets diagnostic criteria for bipolar disorder or psychotic disorder.
• 5. Had a psychotropic medication change within 4 weeks prior to the baseline assessment. Veterans receiving general mental health services or engaging in usual care will be allowed to participate.