It is estimated that over one in ten young people worldwide experiences a diagnosable mental health disorder [1, 2]. Many young people also experience issues with general well-being, requiring support without necessarily fulfilling diagnostic criteria [3]. Left untreated, mental health issues in adolescence can continue into adulthood and cause lasting and disabling effects [4]. Therefore, childhood and adolescence are seen as key periods of mental health intervention [3, 5, 6]. With this in mind, improving young people’s access to services is a main priority [3].
Specialist mental health services are in place for young people but are under increasing pressure, with evidence suggesting a rise in waiting times and high demand for limited resources [5, 7]. Young people may also face barriers to accessing these kinds of professional services, due to fear of stigma, feelings of embarrassment or poor symptom recognition [3, 8]. Many other young people find that they fall below the threshold for specialist care but still suffer the disruptive effects of their mental health experiences [9], with impacts including academic performance, peer and family relationships and self-esteem. This suggests the need for an integrated approach, whereby support systems are woven into other sectors, such as education, to address needs at different levels [3]. Given that young people spend much of their time in school, the development of this setting as a platform for mental health input is a key priority [3, 6].
An increasing number of schools are using peer-led interventions to better integrate mental health support into education [10]. These involve students providing support or education for other young people in their school. These interventions can address a range of issues, such as bullying, school transitions, physical health issues and others. The versatility of peer support makes it a difficult concept to define; however, widely used definitions focus on a number of key components: (1) the intervention is delivered by a peer, to a peer; (2) the intervention is delivered in a structured way, involving training and supervision for the supporters and involvement of the school; and (3) the intervention can be designed to provide education, support or information [11, 12]. Early studies have suggested mixed outcomes following these interventions, but the evidence base remains limited [10, 12, 13].
A proposed model of school-based mental health provision in high-income countries is a three-tiered approach to treatment. This includes (1) ‘universal’ interventions, which target all students in a school or classroom; (2) ‘selective’ interventions, targeting populations deemed at risk of developing mental health issues; and (3) ‘indicated’ interventions, which target young people already exhibiting mental health symptoms [6]. This model has an emerging and encouraging evidence base [14, 15]. Schools may elect to operate a peer support programme within the context of any one of these tiers; interestingly, a survey of peer support programmes in the UK suggested that secondary schools mostly operate targeted peer interventions, while primary schools favour a more universal approach [10]. A separate systematic review and meta-analysis of youth mentoring programmes across all school ages found particularly positive effects of interventions targeted at at-risk young people, though the included studies were not all ‘peer-to-peer’ or conducted within the school environment [16]. This opens up an interesting argument about the most suitable model for implementing peer support programmes in schools.
There are a number of factors that make peer-led interventions suitable to the school setting. Firstly, a major appeal is the potential for peer support programmes to benefit those giving and receiving the intervention, i.e. peer supporters and those they support, in areas such as social skills, communication and self-esteem [10, 13]. Secondly, schools implementing peer-led programmes can select from a large pool of potential peer supporters and, likewise, offer a very accessible service to a broad group of possible users. This could make access simpler and more readily available for young people and can reduce costs and resources for the school. These interventions also have the potential for scalability, that is, sizing up or down depending on demand.
Lastly, neurodevelopmental changes in the adolescent brain mean that peer relationships grow in importance and can strongly influence decision-making, suggesting social influences within their age group play a key role in behaviour [17, 18]. Therefore, young people may be more likely to access this kind of peer-led service compared to more traditional interventions with an adult professional [3]. Close peer support networks have been shown to buffer peer conflict and decrease risky behaviours [18], as well as help young people regulate their responses to stress factors [18] which, given the likelihood of stressors in the school context, justifies the consideration of more formalised school-based peer support systems. Conversely, however, young people have also been shown to display more risky behaviours when accompanied or observed by their peers [17], which suggests the adverse potential of some adolescent dynamics. The significant role of peer influence in adolescent decision-making is clearly complex and warrants further exploration in the context of delivering peer-led mental health interventions.
Examples of peer support programmes exist internationally in schools, colleges and universities. A survey of English primary and secondary schools conducted in 2009 [10], the most recent data available, suggested that around 60% of schools operate some kind of formal peer support scheme. Some of these programmes focus on mental health outcomes specifically, while others address issues more specific to the environment, such as academic attainment, school transitions and bullying. These programmes come under the banner of peer support, peer mentorship, peer counselling, peer buddying, peer befriending and more [10]. There is an identified need within the global literature to understand the connection between these common types and establish an overarching definition of the concept of peer-led intervention in the school context.
Despite the apparent popularity of these interventions, there has been no systematic review to date that specifically examines the mental health outcomes of peer-led interventions in schools.
However, similar reviews have been conducted which show mostly positive, yet inconclusive results. A meta-analysis by Whiston et al. [19] compared the efficacy of different school-based counselling interventions evaluated in both published and unpublished literature. Despite an overall significant average effect size, the authors could not provide clear evidence in support of peer facilitation and mentoring programmes as the outcome measures were largely heterogenous. The analysis may also be limited in its reach by only featuring studies published in the USA.
A separate systematic review and meta-analysis [16] looked at mentoring programmes in both school and community settings for ‘youth’ (pre-kindergarten to secondary school) using ‘non-parental adults or older youth’ as mentors. The study identified 73 eligible studies and a total of 83 separate intervention evaluations within them. Positive effects were observed for most domains, and benefits were particularly noted when ‘older youths’ were the chosen mentors, which supports the evidence for peer-led interventions. The review also identifies four conditions that can influence programme effectiveness: characteristics of youth, mentor recruitment and selection, criteria for matching youth with mentors and mentor-role expectations.
There is evidence of growing governmental interest in peer support. In 2014, the Department of Health published ‘Future in Mind’ [7], which highlighted the importance of mental health support in schools and focuses on peer support as a key area for development. In 2017, the Department for Education commissioned a review of the evidence for peer support programmes in schools [20]. The review found mixed evidence for efficacy but highlighted a lack of reliable data in the field and confusion over definitions and terminology. The report acknowledges the potential benefits of peer support interventions in schools. While not exhaustive, the review gives a helpful overview of some recent large-scale peer support projects and identifies gaps in the evidence base, such as long-term impacts, financial cost of interventions and sufficient comparison with other types of intervention.
Objective of the current review
The evidence base around peer-led interventions in schools is emerging, and there is increasing national and international interest. It is therefore timely to better scrutinise the existing evidence base to understand the potential impact of this approach. This review aims to address this knowledge gap by (1) mapping the range of different peer-led, school-based interventions that have been evaluated in the literature and (2) critically examining the evidence base around the mental health and well-being outcomes of peer-led interventions in school-based settings. This protocol was developed using the PRISMA-P [21] checklist for guidance. The completed checklist can be found as an Additional file 1 to this document.
