Background:The rising prevalence of mental health issues in adolescents and young adults (AYA) has become an escalating public health issue, impacting approximately 10% to 20% of AYA on a global scale. Positive psychology interventions (PPIs) can act as powerful mental health promotion tools, offering an effective means to reach wide-ranging audiences that might otherwise be challenging to access.
Objective:We aimed to conduct a comprehensive synthesis of all randomized controlled trials (RCTs) involving AYA, encompassing both clinical and non-clinical populations, to comprehensively evaluate the effectiveness of digital PPIs within this age group, through a systematic review and meta-analysis.Methods: After a literature search in 9 electronic databases uptil 12 January 2023, and grey literature uptil April 2023, we carried out a systematic review for 35 articles and a meta-analysis of 18 individual studies. PPIs included positive psychology online, digital or smartphone-based interventions in children, adolescents, and young adults with a mean age < 35 years. Outcomes of PPIs were defined as well-being and ill-being. We followed the PRISMA guidelines for studies selection and data extraction, and the CONSORT guidelines for the quality assessment of the studies. Standard mean differences (Hedge's g) were calculated as measures of effect sizes.Results: PPIs included various components, such as online meditation and mindfulness (25.7%), positive psychology and selfcompassion (28.6%), gratitude and acts of kindness (8.6%), optimism and positive emotion (14.3%), relationship satisfaction and acceptance (5.7%), purpose and well-being (14.3%). 74.4% of the included studies focused on ill-being outcomes. For wellbeing outcomes, meta-analytic results showed that PPIs augmented the feeling of purpose, gratitude, and hope, compassion, positive coping behaviors, body-image related outcomes, and positive mindset predisposition. For ill-being outcomes, PPIs reduced cognitive biases, negative emtoions and mood, and stress levels. To note, larger effect sizes were found when a waiting list control group was considered versus digital control group.Conclusions: There's strong evidence that PPIs benefit AYA's well-being, from boosting positive feelings to reducing negative emotions. Digital platforms offer a unique way to address their mental health challenges. Future research should explore how how different PPIs increase well-being compared to other digital interventions.