Exposure to a Mindfulness-Based Education Program Leads to Changes in Diurnal Cortisol in Early Adolescents

There has been a recent call to develop new approaches to promote adolescents’ health and deter the effects of everyday stress by drawing from recent innovations in social-emotional learning (SEL; Durlak et al., 2011). One potentially effective way to promote adolescents’ SEL is through practicing mindfulness (Greenberg & Harris, 2012). Cortisol is a major stress hormone in the human organism and as such is an objective measure to study of the effects of mindfulness interventions (Matousek, Dobkin, & Pruessner, 2010). Yet, to date there are no studies that have examined associations between changes in diurnal cortisol and exposure to a mindfulness intervention in early adolescence. To address this limitation, we examined the effectiveness of the MindUP program on changes in early adolescents’ diurnal cortisol. MindUP is a manualized classroom program designed to enhance children’s well-being via mindfulness practices associated with positive mental health and stress reduction.

Participants included 239 4^th to 7th graders drawn from public elementary schools in a large urban school district in Western Canada. The classrooms were randomly assigned to receive either the MindUP program or serve as controls. Of those students recruited, 91% received parental consent and gave their own assent. Diurnal salivary cortisol collection was facilitated by research assistants who came into participants’ classrooms to assist them throughout the collections at 9 a.m., 11:30 a.m. and 14:30 p.m. at pretest and again at posttest.

Cortisol values at each time point were regressed on the number of hours since awakening. In healthy persons not exposed to chronic stress, cortisol displays a robust diurnal rhythm, with values highest in the morning and gradually decreasing throughout the day. Higher (less negative) values indicate a flatter diurnal cortisol slope, while lower (more negative) values indicate a steeper diurnal cortisol slope. Analysis of Covariance (ANCOVA) with group (intervention vs. controls) as the independent variable and difference in slope from pretest to posttest as the dependent variable (controlling for age, gender, and ESL), revealed that MindUP children’s average slope became more negative (and healthy) from pre- to posttest (Mean = -.02, SD = .06), whereas the average slope for controls changed from a steeper and better regulated diurnal pattern to a flatter and less-regulated (unhealthy) pattern (Mean = .01, SD = .05), F(1, 234) = 11.43, p = 0.01, ES = 047. Feasibility and utility of collecting diurnal cortisol in elementary classrooms will be discussed.