**Background:** Fibromyalgia (FM) is a chronic disorder affecting 1–5% of adults worldwide, characterized by generalized pain, fatigue, sleep problems, mood difficulties, and cognitive dysfunction. Treatment guidelines recommend a multidisciplinary approach including education, pharmacological, exercise, and psychological therapies. Acceptance and Commitment Therapy (ACT) is an evidence-based psychological treatment that aims to improve psychological flexibility—the ability to accept moment-by-moment experiences without judgment and to behave in alignment with personal values. Psychological flexibility comprises six core processes: contact with the present moment, cognitive defusion, acceptance, self as context, values, and committed action. Conversely, psychological inflexibility (the opposite processes) is associated with increased suffering and psychopathology. Many persons with FM face barriers to accessing professional psychotherapy and often turn to online peer support groups (OPSGs), with approximately 25% having participated in such groups. Previous research suggested that some FM patients view OPSGs as a potential substitute for professional mental health services. This study aimed to assess whether content posted in FM Facebook OPSGs emulates the psychological flexibility principles underlying ACT.
**Methods:** The authors conducted a complete re-analysis of previously collected data from three large FM Facebook OPSGs (minimum 500 members each). Data were collected using nonparticipatory observational methodology over a 7-day period, plus archived posts from the same 7-day period of the previous two months (14 days for one group due to technical limitations). Approximately 600 posts and associated responses (>33,000 kilobytes of data) from 1121 unique members were collected. Most participants appeared to be North American women, with illness duration ranging from months to decades and ages from 20s to 70s. Fewer than 10 members self-identified as male or non-North American. Deductive thematic analysis was guided by the psychological flexibility/inflexibility model, using a coding template developed from the works of Hayes and Harris, reviewed by two external clinical psychologists. The first author coded all posts and responses using NVIVO-12 software, keeping an audit trail and engaging in discussion with the second author and laboratory colleagues to ensure trustworthiness.
**Key Results:** Content aligning with psychological flexibility processes occurred sporadically and generally elicited brief, vaguely supportive responses (e.g., smiley emoji, “thank you for sharing”). In contrast, content aligning with psychological inflexibility processes was consistently posted and highly salient across all three groups. Individual posts often reflected more than one inflexibility process. Inflexible content frequently provoked multiple responses conveying solidarity or validating aspects of psychological inflexibility. Specific findings for each process pair: (1) Contact vs loss of contact with the present moment: Present-focused posts were rare and positively received; past- or future-oriented posts were common, with members worrying about anticipated symptoms or longing for life before FM. (2) Cognitive defusion vs fusion: Defusion posts were rare (e.g., pointing out that setting boundaries is not “ugly”); fusion posts were very prominent, with members expressing unquestioning belief in negative thoughts and perceived helplessness. (3) Acceptance vs experiential avoidance: Acceptance was rarely expressed explicitly; experiential avoidance was frequently advised (e.g., medication, supplements, resting, avoiding stressors). (4) Self as context vs fusion with a conceptualized self: Self-as-context content was very scarce; fusion with negative self-concepts (e.g., “worthless”, “useless”) or with a “warrior” identity was common. (5) Values vs lack of values clarity: Values were discussed uncommonly; when mentioned, they were often couched in content about increased symptoms from values-based activities. Many members described struggling with socially dictated standards without clarifying why they were valued. (6) Committed action vs unworkable action: Committed action occurred periodically (e.g., “I make memories wherever I can”); unworkable action was prominent, with members prioritizing avoidance of distress over valued activities. No notable differences were found between the three groups.
**Clinical Implications:** The findings indicate that FM OPSGs are more likely to expose members to psychologically inflexible content than flexible content, which is concerning because psychological inflexibility is consistently associated with negative outcomes in chronic pain populations. The authors suggest that a combination of individual characteristics (e.g., high internalized inflexibility, lack of opportunities to learn flexible approaches, stigmatization) and group mechanisms (e.g., rules requiring kindness that may discourage challenging inflexible beliefs, the structure of OPSGs that may promote past/future focus) likely contribute to this prominence. FM OPSGs should not be considered a substitute for professionally delivered ACT, but they may serve a valuable role in providing foundational emotional support for individuals not yet ready for active psychotherapy. Clinicians should discuss the pros and cons of OPSG participation with patients to help them make informed choices. Limitations include the inability to collect demographic data or assess members' internalized flexibility, and the possibility that groups with more flexible content exist but were not included. Future research should explore professionally moderated ACT-based Facebook groups as a potential accessible resource.