The open-label clinical study explores potential modifiable predictors of treatment outcomes in a sample of 55 military service members and veterans with clinically significant PTSD symptoms who receive Intensive Outpatient Prolonged Exposure (IOP-PE).

Intensive Outpatient Prolonged Exposure (IOP-PE) is a three-week, intensive, individualized program that combines massed Prolonged Exposure with military-relevant treatment augmentations to treat posttraumatic stress disorder (PTSD; Peterson et al., 2018). Recent findings indicate that IOP-PE significantly decreased combat-related PTSD in post-9/11 service members and veterans (Peterson et al., 2019). However, IOP-PE is costly and requires a considerable commitment from the patient. Being able to prospectively identify which patients benefit most from IOP-PE will help treatment providers and patients make well-informed decisions about clinical care. The primary aim of this prospective, exploratory clinical study is to investigate potential predictors of treatment outcome following 15 sessions of IOP-PE delivered over 3-weeks in a sample of 55 military service members and veterans (i.e., individuals who have retired or separated from the US Armed forces, active duty personnel, reservists, and National Guardsmen/women) with significant PTSD symptoms. A follow-up assessment will be conducted one-month following the completion of treatment.

Predictor variables will include the following:

Aim 1: The PTSD Beliefs Inventory, the Dispositional Resilience and Disability Inventory, and the Credibility/ Expectancy Questionnaire.

Aim 2: The Disability-Recovery Implicit Association Test.

Aim 3: The Treatment Motivation Questionnaire and Service Connection Status

Aim 4: The Insomnia Severity Index, the Dimension of Anger Reactions-5, Patient Health Questionnaire-9, the Quick Drinking Screen, and the Pain Intensity, Enjoyment, and General Activity (PEG) Scale.

Inclusion Criteria:

1. Active duty military service members or veterans (18 years or older) who were impacted by Hurricane Harvey.
2. Significant PTSD symptoms as measured by a Posttraumatic Stress Disorder Checklist (PCL-5) score of 34 or higher.
3. Able to speak and read English (due to standardization of outcome measures)
4. Able to participate in a three-week intensive outpatient program

Exclusion Criteria:

1. Current manic episode or psychotic symptoms requiring immediate stabilization or hospitalization (as determined by the bipolar and psychosis modules of the Mini International Neuropsychiatric Interview (MINI) and clinical judgment)
2. Current and severe alcohol use warranting immediate intervention based on clinical judgment.
3. Evidence of a moderate or severe traumatic brain injury (as determined by the inability to comprehend the baseline screening questionnaires)
4. Current suicidal ideation severe enough to warrant immediate attention (as determined by the Depressive Symptoms Index - Suicidality Subscale and the Self-Injurious Thoughts and Behaviors Interview short form) and corroborated by a clinical risk assessment by a credentialed provider.
5. Other psychiatric disorders severe enough to warrant designation as the primary disorder as determined by clinician judgment