Comparing the effects of sitting meditation and body scan on working memory in undergraduate healthcare students: a single-blind randomised trial.

Suicide is one of the leading causes of death among adolescents worldwide and constitutes a major public health challenge. Globally, approximately 100,000 suicide deaths occur annually among individuals aged 15–29, making it the fourth leading cause of death in this age group []. Beyond mortality, suicidal behaviors—including ideation, plans, and attempts–exert a profound impact on adolescents’ long-term development and affect family and societal stability. In China, suicide ranked as the fourth leading cause of injury-related death in 2021 and the second among those aged 15–44 []. In the United States, emergency department visits for suicidal ideation or attempts among youth aged 5–18 doubled between 2007 and 2015 []. A multinational study involving adolescents aged 12–15 from 83 countries reported global prevalence rates of 16.5% for suicidal ideation, 16.5% for plans, and 16.4% for attempts [], indicating that non-fatal suicidal behaviors are widespread among adolescents worldwide. Existing evidence suggests that adolescent suicidal behaviors result from the interplay of multiple factors, including demographic characteristics (e.g., gender, race/ethnicity), psychosocial factors (e.g., academic pressure, interpersonal relationships), health behaviors (e.g., smoking, alcohol consumption, sleep duration), and mental health conditions (e.g., depression, anxiety) [–]. Among these factors, sleep has emerged as an important determinant of adolescent mental health and well-being. Healthy sleep is characterized by adequate duration, regular timing, good quality, stable circadian rhythms, and the absence of disturbances or disorders. As the most intuitive and quantifiable indicator of sleep health, sleep duration is widely used in research examining the relationship between sleep and health outcomes []. Numerous studies have shown that optimal sleep enhances attention, behavioral control, cognitive function, and emotional regulation, thereby promoting adolescents’ physical and mental well-being [–]. The traditional “U-shaped” association hypothesis posits that both short sleep (typically < 6 h per night) and long sleep (> 8 h per night) are associated with adverse mental health outcomes and may be linked to suicidal behaviors [, ].