APA Dictionary of Psychology

a research study designed to evaluate strategies that delay, reduce, or prevent the onset of a disease or health condition. These trials may include participants who are generally healthy as well as those with specific risk factors or characteristics that make them more susceptible to the condition under study. For example, a prevention trial could investigate whether digital mental health interventions, mindfulness-based programs, or physical activity initiatives can reduce the risk of anxiety or depression in adolescents and young adults experiencing chronic stress.