Understanding and Defining Young People's Involvement and Under-Representation in Mental Health Research: A Delphi Study

Introduction: The mental health of young people (aged 16-25 years) is a growing public health concern in the United Kingdom due to the increasing numbers of young people experiencing mental health difficulties, with many not in contact with mental health services. To design services that meet the needs of all young people, a diversity of young people must be involved in mental health research, beyond being participants. This Delphi study aimed to identify different types of 'involvement' and to define and describe 'under-representation' in young people's involvement in mental health research.

Methods: Twenty-seven experts in young people's mental health research completed a series of online questionnaires. The experts were academic researchers, patient and public involvement (PPI) professionals and young 'experts by experience'. Round 1 generated panellists' views on 'involvement' and 'under-representation'. Round 2 summarised panellists' responses from Round 1 and sought consensus (minimum 70% agreement) in nine question areas. Round 3 validated the findings of the previous rounds.

Results: Consensus was achieved in eight out of nine areas, resulting in a matrix (with definitions) of the different types of young people's involvement in mental health research, from being advisors to involvement ambassadors. The findings generated an agreed-upon definition of under-representation, an identification of when in the research process there is under-representation and the characteristics of the young people who are under-represented. Experts further agreed on demographic data that should be collected to improve reporting on involvement.

Conclusions: This study adds to our understanding of involvement and under-representation in the context of young people's mental health research through expert consensus. It provides a practical resource for researchers considering involving young people in the research process and suggests the data that should be collected to improve reporting on the diversity of the young people involved.

Patient And Public Contribution: A research oversight group of five young people advised on this study. They contributed throughout the project-from endorsing the research question to commenting on the findings and dissemination. Two of the group reviewed all participant materials and piloted the initial questionnaire.