Online IFS Therapy for PTSD: Feasibility, Acceptability & Trial Results

A new study suggests that a group-based therapy approach rooted in Internal Family Systems (IFS) may offer a feasible and acceptable way to treat posttraumatic stress disorder (PTSD). The research, initially focused on feasibility and acceptability, builds on the growing body of evidence supporting IFS as a valuable tool in mental health care, particularly for complex trauma. This approach is particularly notable for its potential to reach individuals who might not otherwise engage with traditional treatment models.

Understanding Internal Family Systems

Internal Family Systems is a model of psychotherapy that views the mind as comprised of various “parts”—subpersonalities—each with its own unique perspective, feelings and motivations. These parts aren’t seen as pathological, but rather as distinct elements within a complex internal system. IFS therapy aims to support individuals understand and harmonize these parts, fostering self-compassion and inner healing. A core tenet of IFS is the belief in the “Self,” a core of wisdom, compassion, and calmness that exists within everyone. Psychology Today offers a detailed overview of the IFS model, explaining how it differs from other approaches.

Proof-of-Concept and Expanding Research

The initial proof-of-concept study, published in Psychological Trauma: Theory, Research, Practice, and Policy in 2024, evaluated an online, group-based IFS program called the Program for Alleviating and Resolving Trauma and Stress (PARTS). Researchers, led by Alexandra Comeau and Zev Schuman-Olivier, assessed the feasibility and acceptability of the program for individuals diagnosed with PTSD. The study involved 10 participants and focused on whether the program could be delivered effectively online and whether participants found it helpful and would recommend it to others. The findings were promising, with high ratings of acceptability (86%) and willingness to refer a friend (92%), and a 70% completion rate.

Building on this initial work, a larger randomized controlled trial (RCT) is underway, further investigating the efficacy of the PARTS program. Details of this ongoing RCT were published in advance online in the same journal in March 2025. The study details outline the rigorous methodology being employed to assess the impact of online group-based IFS therapy on PTSD symptoms.

Addressing Comorbidity: PTSD and Substance Use

Recent research highlights the particular relevance of IFS for individuals experiencing both PTSD and substance use disorder (SUD). These co-occurring conditions are common and often present significant challenges for treatment. Traditional interventions have shown limited efficacy and high attrition rates. The PARTS-SUD program, a variation of the PARTS program, specifically targets this population. A pilot study of PARTS-SUD, involving ten adults with comorbid PTSD and SUD, demonstrated not only acceptability and feasibility but also reductions in both PTSD symptom severity (1.7 points/week reduction) and craving (0.25 points/week reduction). These findings, published in Frontiers in Psychiatry, suggest that an online IFS intervention can be a viable treatment option for this complex population. The National Institutes of Health’s PubMed database provides access to the full study.

What the Research Tells Us – and Doesn’t

It’s important to note the limitations of these studies. The initial proof-of-concept study and the PARTS-SUD pilot both involved small sample sizes (10 participants each). While the results are encouraging, they cannot be generalized to the broader population of individuals with PTSD or PTSD-SUD. The pilot studies were also single-arm designs, meaning there was no control group for comparison. This makes it difficult to determine whether the observed improvements were directly attributable to the IFS intervention or to other factors, such as natural recovery or the therapeutic relationship. The ongoing RCT is designed to address these limitations by including a control group and a larger, more diverse sample.

the studies primarily assessed acceptability, feasibility, and preliminary clinical outcomes. While reductions in PTSD symptoms and craving were observed in the PARTS-SUD pilot, further research is needed to determine the long-term effects of the intervention and to identify the mechanisms of action that contribute to its effectiveness. The researchers emphasize the need for a larger, randomized controlled trial to confirm these findings.

The Rise of Telehealth and Group Therapy

The increasing use of online and group-based therapy formats is a significant trend in mental health care. Telehealth offers several advantages, including increased accessibility, convenience, and affordability. Group therapy provides a supportive environment where individuals can share their experiences and learn from others. The combination of these two modalities—online group-based IFS therapy—may be particularly well-suited for addressing the needs of individuals with PTSD and related conditions. The Substance Abuse and Mental Health Services Administration (SAMHSA) offers resources for finding mental health support, including telehealth options.

Next Steps: Ongoing Trials and Future Directions

The current randomized controlled trial of the PARTS program is a crucial next step in evaluating the efficacy of this intervention. The results of this trial will provide more definitive evidence regarding the benefits of online group-based IFS therapy for PTSD. Researchers are also exploring the potential of IFS to address other mental health conditions, such as anxiety, depression, and eating disorders. Further investigation into the specific mechanisms of action underlying IFS—how it works to promote healing and well-being—is also warranted. The field will be watching for the full publication of the RCT results, which will inform future clinical practice and research directions.