Why Do People With PTSD Stay in Group Exposure Therapy Longer Than Individual Exposure Therapy?

Summary: A new study shows people with PTSD stay in group exposure therapy longer than they stay in individual exposure therapy.

Key Points:

• Prolonged exposure therapy (PE) is well-established as an effective treatment for reducing symptoms of post-traumatic stress disorder (PTSD).
• Typical PE therapy occurs in individual, one-on-one sessions in an outpatient context.
• Group PE is a type of prolonged exposure therapy designed for delivery/facilitation by trained providers in group context.
• A recent study on veterans with PTSD indicates peer support in the group context may promote increased retention, i.e. staying in treatment longer.

Exposure Therapy (PE) is Effective for PTSD

The symptoms of PTSD can be extremely disruptive and prevent people diagnosed with PTSD from full and productive functioning in many areas of life. Symptoms at any level of intensity – mild, moderate, or severe – can disrupt relationships and performance at work and school. However, intense, severe, complex PTSD can cause symptoms that completely impair function, and, for some patients, make participating in the basic activities of daily life virtually impossible.

The development of trauma-informed therapies and extensive work and fine-tuning on exposure-based therapies such as prolonged exposure therapy (PE) and eye movement desensitization and reprocessing therapy (EMDR) enables many patients with PTSD to decouple negative emotions from memories associated with traumatic events, which allows them to manage symptoms and participate fully in typical daily activities.

Exposure and related therapies are effective for severe PTSD, and can help people with complex trauma and people with severe PTSD – often military combat veterans – reduce and manage their most disruptive PTSD symptoms.

Research shows that retention – i.e. staying in – exposure therapy can be a problem for people in PTSD treatment, with veterans showing high dropout rates across the board, and consistently higher dropout rates than civilians.

A study published in 2021 comparing PTSD treatment dropout rates between veterans and civilians shows the following:

• Veterans: 32.9%
• Civilians: 17.2%

Another more recent meta-analysis – which we’ll discuss below – focuses on dropout rates among military personnel, with data indicating veterans with PTSD stay in group exposure therapy longer than individual exposure therapy.  For the rest of this article, we’ll share the relevant results from that study, and close with the possible reasons people with PTSD stay in group exposure therapy longer than individual exposure therapy.

Examining Dropout Rates in PTSD Treatment

The large-scale meta-analysis “The Protocol Matters: A Meta-Analysis of Psychotherapy Dropout From Specific PTSD Treatment Approaches in U.S. Service Members and Veterans,” published in 2025 by the American Psychological Association (APA), examined data from 181 studies PTSD with treatment information on 124,092 current and former military personnel with PTSD. Here’s their primary research goal:

“To estimate dropout among specific PTSD treatments in United States military populations.”

This was not only one of the largest studies on PTSD conducted to date, but it was also the only of its size to drill down on dropout rates and explore possible explanations for different dropout and retention rates associated with various therapies for PTSD. We’ll focus specifically on dropout rates for exposure therapies, and share other relevant data to add understanding and perspective.

First, let’s look at the overall dropout estimates after thorough statistical analysis.

All PTSD treatments:

• Cumulative dropout rate: 25.6%

While that’s lower than the dropout rates in the first study we cited, above, it’s 48 percent greater than the civilian dropout rate. Next, let’s look at what we’re most interested in: dropout rates for exposure therapies. Specifically, those delivered in weekly outpatient appointments with professional mental health providers.

All Weekly Outpatient Exposure Therapies Dropout Rates, Highest to Lowest

• Virtual Reality Exposure Therapy: 37.2%
• Prolonged exposure therapy (PE): 34.7%
• Eye movement desensitization and reprocessing (EMDR): 13.6%
• Written exposure therapy (WET): 19.8%
• Group-based exposure therapy (GBET): 6.9%

Those figures are, in a word, astounding.

Veterans drop out of standard, individual PE at a rate 400 percent greater than they drop out of group-based PE. Before we explore why, let’s take a look at estimated dropout rates for mindfulness-based approaches, which are gaining in acceptance and popularity in all PTSD populations, including veteran and civilian.

All Mindfulness PTSD Treatments: Dropout Rates Among Veterans

• Total dropout rate: 17.3%
• Nonspecific mindfulness protocols: 25.2%
• Mindfulness-based stress reduction (MBSR): 20.0%
• Transcendental meditation: 16.8%
• Mantram repetition program: 10.3%

These figures show us that retention in group PE is significantly greater than mindfulness based treatments, including the recently developed mantram approach, which involves combining mindful meditation with repeated verbal mantras.

We’ll discuss these outcomes below.

Why Group Exposure Therapy Over Individual Exposure Therapy?

Before we address that question, we’ll explain possible reasons this data on therapy for veterans can transfer to therapy for the civilian population.

First, decades of evidence shows that PTSD treatment for veterans also works for civilians, and effective treatments for veterans are particularly effective for civilians with complex trauma and complex PTSD. Second, the Veterans Administration has studied PTSD more extensively than any other public research body, and their data receives significant scrutiny before publication. Finally, people who identify with the military ethos – to oversimplify, we mean the strong silent types – are notoriously resistant to therapy, psychotherapy, discussing their feelings, and revealing anything that may be a sign of weakness, which is exactly what happens in PTSD treatment.

Since veterans are among the most likely to resist treatment related to emotional difficulties, it’s logical to propose we can learn lessons from treatments veterans will accept, commit to, and complete, and apply those lessons to civilians who may share an overlapping ethos or resist PTSD treatment for similar reasons.

The study authors theorize the greater retention rates for group PE compared to individual PE revolve around the presence of peers and other related factors.

Group PE vs. Individual PE: Possible Reasons for Retention

• Use of cohesion building exercises with other group members
• Common practice of arranging ways for group members to connect with other group members before starting group therapy sessions.
• Regular use of peer-based homework, e.g. peer group members call one another between sessions to complete therapy assignments
• Immediate peer support – i.e. they’re present during exposure – may make exposure more tolerable than during on-on-one treatment
• Focus on shared experiences of moral injury
• Focus on shared experiences of grief, shame, and guilt

What we take away from those points is this:

There’s safety in numbers, and more safety when those numbers, i.e. people, share a similar experience, similar responses, and similar psychological and emotional challenges stemming from a shared, similar experience.

With this point of view, it’s possible to create group PE groups made up of patients with similar backgrounds and similar traumatic experiences. Members may be more willing to listen, share, and learn from those who’ve been through something they can relate to and identify, rather than engaging in the same process in one-on-one, individual exposure therapy.