Assessing Similarities and Differences in Thematic Content Across Online Mental Health Communities Dedicated to Trauma-Related Mental Health Conditions

Objective: Large online mental health communities exist for both posttraumatic stress disorder (PTSD) and complex posttraumatic stress disorder (CPTSD) on Reddit. These communities have not been sufficiently understood through prior work. Method: Posts (N = 86,267) from r/ptsd and r/CPTSD subreddits from December 2020 to December 2022 were collected, processed, and assessed. A modified reflexive thematic analysis was used to generate themes and codes from corpus data and Bidirectional Encoder Representation from Transformers topic models. Representative posts (N = 397) were coded. Chi-square analyses were used to compare the frequency of themes and codes across r/ptsd and r/CPTSD. Results: Most sampled posts in r/ptsd and r/CPTSD were focused on posting for oneself. Venting was significantly more common in r/CPTSD (p < .01), whereas seeking advice was more frequent in r/ptsd (p < .01). Traumatic experiences, mental health symptoms, treatment, diagnosis, and relationships were discussed frequently in both communities. Discussions of noninterpersonal trauma, anxiety symptoms, sleep-related symptoms, flashback/reexperiencing symptoms, somatic symptoms, diagnosis, and medication use were significantly more prevalent in r/ptsd compared to r/CPTSD (p < .01). Discussions of depression/mood symptoms, resources/coping tools, and interpersonal conflict were significantly more common in r/CPTSD (p < .01). Conclusions: Findings suggest that trauma-related online mental health communities may allow users to fulfill different objectives (i.e., seeking support, venting, or asking for advice) related to a wide range of discussion themes. Findings may be used to help inform the design and delivery of informal and formal interventions directed at these communities.