Background: Scalable, low-threshold interventions for personality disorders and personality difficulties (ICD-11) remain limited. We developed GPM-I, a guided digital self-help adaptation of Good Psychiatric Management, to deliver structured psychoeducation and support early change efforts.

Methods: We conducted a naturalistic feasibility study in routine psychiatric care in Stockholm, Sweden. Feasibility outcomes included engagement and standard program completion (Modules 1-2) and optional advanced module uptake (Modules 3-6). Acceptability was assessed with the Client Satisfaction Questionnaire (CSQ-8) and negative effects with the Negative Effects Questionnaire (NEQ). Weekly distress (CORE-10) was analyzed using linear mixed-effects models.

Results: Of 131 patients offered access, 78 (59.5%) initiated the program by completing Module 1 (engagement threshold). Participants were 71.8% women; mean age was 35.2 years. Participants were categorized as having personality disorder (n = 18), personality difficulties (n = 22), or other diagnoses (n = 38). Among initiators, standard program completion (Modules 1-2) was observed in 40/78 participants (51.3%), and 13/78 (16.7%) completed all available modules (Modules 1-6). CSQ-8 respondents (28/78, 35.9%) reported moderate satisfaction, with 85.7% rating overall satisfaction in the two highest categories, but completion of CSQ-8 and NEQ was low. Negative effects were reported by 25/27 NEQ respondents (92.6%), most often increased stress/ pressure or emotional strain. CORE-10 decreased significantly over time with a small effect size.

Conclusion: GPM-I showed moderate engagement and moderate acceptability among respondents, alongside generally mild-to-moderate negative effects. Findings support continued refinement of the procedures and can inform the design of a controlled trial.