Trauma-related guilt is common and impairing among trauma survivors, particularly among Veterans with posttraumatic stress disorder (PTSD). The investigators' work shows that a brief treatment targeting trauma-related guilt, Trauma Informed Guilt Reduction Therapy (TrIGR), can reduce guilt and PTSD and depression symptoms. Whether TrIGR is no less effective than longer, more resource heavy PTSD treatments disseminated by by VA, like cognitive processing therapy (CPT), is the next critical question that this study will seek to answer. 158 Veterans across two VA sites will be randomized to TrIGR or CPT to evaluate changes in PTSD, depression, guilt and shame symptoms across the two treatments.

Trauma-related guilt is common and impairing among trauma survivors, particularly among treatment seeking Veterans with posttraumatic stress disorder (PTSD). Although evidence-based trauma-focused PTSD treatments such as Cognitive Processing Therapy (CPT) are effective to treat PTSD and trauma-related guilt, many still experience symptoms or maintain their diagnosis after treatment, and dropout from these generally 12+ session protocols is high. Veterans show lower response and higher dropout than others with PTSD. Delivering protocols that are generally 12 or more sessions challenges the Veterans Affairs (VA) healthcare system given high demand for mental health care. For these reasons, additional and less burdensome approaches are needed. Brief treatment that targets mechanisms that are distressing and associated with multiple problems and disorders may be an understudied but promising way to treat PTSD and other posttraumatic psychopathology. The investigators' work shows that a brief treatment targeting trauma-related guilt and shame, Trauma Informed Guilt Reduction Therapy (TrIGR), can reduce guilt, PTSD, depression, and distress among Veterans and help them reengage with activities they find meaningful. Whether TrIGR is no less effective than longer, more resource heavy evidence-based PTSD treatments disseminated across by VA, like CPT, is the next critical question.

The proposed randomized clinical trial (RCT) will be the first non-inferiority trial of TrIGR and the first to compare TrIGR to a first tier PTSD treatment, specifically CPT. It will also be the first to evaluate TrIGR with Veterans from all eras with guilt from any type of traumas, as the investigators previous work was exclusively with Veterans of the conflicts in Iraq and Afghanistan with deployment-related traumas. 158 Veterans across two VA sites will be randomized to TrIGR or CPT. Exclusion criteria will be minimal so that generalizability will be high. Treatment will be delivered in VA mental health clinics. The primary aim is to evaluate if TrIGR is non-inferior to CPT in reducing PTSD symptom severity among Veterans with PTSD who endorse trauma-related guilt. Secondary aims are to evaluate TrIGR's non-inferiority relative to CPT regarding depression severity. The investigators will explore potential mechanisms of treatment, such as the relationship between change in guilt and shame change in PTSD symptoms. The study is critical to establish whether TrIGR is effective for a much larger group of Veterans and whether it is as effective as longer treatments already available in VA to inform if TrIGR warrants further study and dissemination in VA.

Inclusion Criteria:

• U.S. Veterans age 18 or older;
• meets diagnostic criteria for PTSD or subthreshold PTSD;
• a score of 2 or higher ("true" to "extremely true") on feeling trauma-related guilt much or all of the time or scoring 3 or higher ("very true" or "extremely true") on at least one guilt cognition factor (hindsight bias/responsibility, wrongdoing, or lack of justification) on the Trauma Related Guilt Inventor.
• not currently receiving trauma-focused treatment such as CPT or PE; and
• willingness to attend psychotherapy and assessment sessions.

Exclusion Criteria:

• Impaired mental status as measured by the Montreal Cognitive Assessment (MoCA) (score < 21) and confirmed by a neuropsychologist,
• Veterans with significant current risk of suicidal/homicidal behavior will be referred to more appropriate treatment;
• Current severe substance use disorder (in the past two months) based on DSM-5 criteria;
• Current unmanaged psychosis or mania;
• life threatening or unstable medical illness; or
• inability to read.

A de-identified, anonymized dataset without personal identifiers will be generated and shared with those who request and are granted access (see access criteria). Any HIPAA identifiers, or combinations of variables that could be used for re-identification, will be excluded, as will any proprietary information. The plan does not include any access to individually identifiable or proprietary data. Therefore, this plan will ensure the protection of personal privacy, the confidentiality of individually identifiable private information, and the security of proprietary data and information.

After publication of the primary outcome paper.

Requests for access must be made in writing signed by a requester from the United States and include an email address for delivery and an assurance that the recipient will not attempt to identify or re-identify any individual. The request should reference the publication underlying the request.

A computer-generated masked randomization sequence will be provided and held by a statistician not otherwise involved in the study. Randomization will be stratified by site and gender.