Developing a Transdiagnostic Unified Protocol for Nigerian Cultural Context: Adapting Evidence-Based Treatment for Emotional Disorders Across Cultural Boundaries

The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders is an evidence-based treatment targeting shared psychological mechanisms across anxiety and depression disorders, yet no culturally adapted version exists for Nigerian populations, representing a critical clinical research gap. This study develops and conducts a preliminary randomised controlled trial of a culturally adapted Nigerian Unified Protocol across three Nigerian cultural communities. Phase 1 applies systematic cultural adaptation methodology including qualitative focus groups with 30 clinical psychologists and 40 patients from Yoruba, Hausa-Fulani, and Igbo communities to identify required cultural modifications. Phase 2 conducts a pilot randomised controlled trial comparing the Nigerian Unified Protocol against waitlist control in 120 adults with emotional disorders (anxiety and depression) at three outpatient mental health clinics in Ibadan, Kano, and Enugu. The DASS-21, the Emotion Regulation Questionnaire, and neurobiological well-being markers including heart rate variability are assessed at baseline, post-treatment, and three-month follow-up. Mixed ANOVA and effect size analyses evaluate preliminary efficacy. Barlow's Unified Protocol Theory, the Cultural Adaptation of Evidence-Based Treatments Framework by Bernal, and the Cultural Formulation Model provide the theoretical framework. The original contribution is Nigeria's first culturally adapted transdiagnostic psychological treatment protocol, filling a critical gap in accessible evidence-based psychological care. Findings will directly advance clinical psychology practice across Nigerian mental health settings. Keywords: Unified Protocol, transdiagnostic treatment, cultural adaptation, emotional disorders, Nigeria.