New research by żě˛ĄĘÓƵ doctoral candidate Cassandra Harmsen is shedding light on a form of trauma care that remains understudied and underused: online group therapy.
For people who have experienced trauma, early support is critical for regulating distress and restoring a sense of safety. But Harmsen, a PhD candidate in York’s Clinical‑Developmental Psychology program and the Trauma & Attachment Lab, notes that individualized, in‑person therapy isn’t always accessible. Cost, distance, time constraints, mobility challenges and a shortage of trained clinicians can all stand in the way.
During – and after – the COVID‑19 pandemic, many mental health services shifted online to reach more people, she explains. Alongside individual sessions, clinicians also began offering more virtual group formats. Trauma therapy in that format allows multiple survivors to receive care at once. The virtual format can foster a sense of shared understanding and may reduce stigma by helping participants see their responses as common, rather than isolating.
Despite its potential, Harmsen says group therapy remains an underused resource, in part because of lingering public hesitation. That gap helped inspire a research project she's been part of, now published in the International Journal of Group Psychotherapy, which tested whether online, skills‑based trauma groups could offer meaningful early‑stage support – and how to make them as effective as possible.
The project was developed by a team at York's Trauma & Attachment Lab, directed by psychology professor Robert T. Muller. Harmsen worked collaboratively with Muller and York postdoctoral fellow ł§˛ą°ů˛ąĚý¸é±đ±č±đ˛Ô»ĺ˛ą,Ěý±Ęłó¶ŮĚýł¦˛ą˛Ô»ĺľ±»ĺ˛ąłŮ±đĚýGeorge Langdon, and clinical psychologist Anna Baranowsky. The team designed an eight‑week, skills‑based trauma program delivered in partnership with the community organization Trauma Practice for Healthy Communities. The initiative was offered entirely online and focused on grounding, self‑regulation, basic coping strategies and psychoeducation – tools to help individuals manage distress safely, without detailed trauma disclosure.
“Our guiding goal was to understand how to create an online program that was informative, practical and helpful, particularly during a difficult time,” Harmsen says.
The study followed 178 adults who took part in a series of small, closed online groups between 2020 and 2024. To assess impact, the research team compared changes in participants’ symptoms before the group began with those measured after the final session.
The results were encouraging. PTSD symptoms declined much more after participants completed the program than during the waiting period beforehand, suggesting the program's success. About one‑third of people showed clinically meaningful improvements, with symptoms easing across areas such as intrusive memories, avoidance, and negative mood and thinking. More than a quarter of those who initially scored in the range associated with probable PTSD fell below that screening threshold by the end of the program.
Soon after completing that project, the research team conducted a follow‑up study to better understand why some participants benefited more than others. Although online trauma groups are increasingly used, Harmsen says far less research has examined the factors that help explain how and why they work.
“There are so many different types of therapy,” she says. “Identifying when online group therapy is most successful, and how to use it effectively, is important.”
The follow‑up study examined the experiences of 80 adults drawn from the same community‑based program. Those who participated completed symptom questionnaires before and after the experience, along with post‑program feedback on dynamics and satisfaction.
What stood out most was that satisfaction – not group climate – predicted improvement. Participants who felt the techniques were clearly explained, easy to understand and practical in everyday life showed the largest reductions in trauma‑related symptoms.
In the paper, the researchers note this does not mean the collective setting was unimportant; rather, the findings suggest that for early‑stage, skills‑based trauma groups, the primary value comes from expanding access and delivering practical tools safely and efficiently. Individual improvements, however, depend on how clearly those tools are taught and how easily they can be applied in daily life.
Harmsen stresses that more research is still needed, including randomized trials and longer‑term follow‑up. In the meantime, she hopes the work highlights how early stabilization in online group settings can be a valuable part of broader trauma‑care pathways, and encourages clinicians to think carefully about how similar programs are designed and facilitated.
“Understanding how to make online group therapy as effective as possible will help make services more accessible to those in need,” she says. “I hope this research encourages people to consider using online group therapy in their practices and provides some guidance on how to make the most of these groups.”