Abstract
INTRODUCTION: The prevalence of mental health and substance use disorders is rising globally, significantly affecting not only individuals but also their families, loved ones, and carers. These affected loved ones are often overlooked despite providing unique insights that can contribute to the development of resources/interventions for these disorders. Co-production, a participatory approach in which public members are involved as equal partners in research, offers a valuable framework for including these individuals. However, involving affected loved ones presents specific challenges due to their emotional and vulnerable position. METHODS: This systematic review aimed to address three questions: (1) What co-production procedures are used with affected loved ones in developing mental health and substance use resources/interventions? (2) How do researchers and stakeholders assess co-production experiences? (3) What components of co-production facilitate the involvement of the affected loved ones of those with mental health and substance use disorders or concerns? Eligible studies included at least one affected loved one in the co-production development of a mental health or substance use resource/intervention, provided a description of the co-production approach, and were in English. All dates were included in searches across seven databases using the Mixed Methods Appraisal tool and an adapted co-production checklist. RESULTS: Content and thematic analyses were conducted, revealing three key themes for the meaningful involvement of affected loved ones in co-production: creating a safe and trusting environment, facilitating accessibility and open dialogue, and integrating diverse perspectives. Additionally, the review found variability in the use of co-production terminology. DISCUSSION: These findings underscore the importance of prioritising inclusive, sensitive co-production approaches to ensure that the voices of those supporting individuals with mental health and substance use disorders are heard and valued. Future research should aim to clarify these terms and adopt standardised reporting styles to ensure sufficient detail and consistency in reports.