1 Department of Educational and Counselling Psychology, McGill University, 3700 McTavish Street (Room 614), Montreal, QC, H3A 1Y2, Canada, 1 514-398-4242.
2 Department of Psychology, Carleton University, Ottawa, ON, Canada.
3 Department of Applied Psychology and Human Development, University of Toronto, Toronto, ON, Canada.
4 Campus Wellness and Support Services, Concordia University, Montreal, QC, Canada.
5 Office of the Deputy Provost, Student Life and Learning, McGill University, Montreal, QC, Canada.
6 Student Wellness Hub, McGill University, Montreal, QC, Canada.

Background: Mindfulness-based programming (MBP) is increasingly being implemented within university settings to support students' mental health, and it typically includes the instruction of formal mindfulness (FM) and informal mindfulness (IM) activities. However, recent evidence suggests that university students with a history of nonsuicidal self-injury (NSSI) may experience challenges in response to FM (eg, physical or psychological discomfort), whereas the flexibility and brevity inherent in IM may be better tolerated.

Objective: This randomized controlled trial compared web-based FM and IM programs to each other and to an inactive control condition in terms of (1) effectiveness and (2) acceptability as a function of NSSI history (NSSI or no NSSI) and time (1 week after the program or 1 month after the program). Indices of effectiveness included dispositional mindfulness, well-being, perceived stress, psychological need satisfaction, emotion regulation styles, and academic engagement.

Methods: Participants were university students with (n=127) and those without (n=100) past-year NSSI engagement. All procedures were conducted online. Once informed consent was obtained and eligibility was confirmed, participants were randomly assigned to 1 of 3 conditions: FM program, IM program, or inactive control condition. One week before the FM and IM programs commenced, all participants completed a baseline survey assessing all indices of effectiveness. Participants assigned to the FM and IM conditions then attended hour-long mindfulness program group sessions once per week over 4 consecutive weeks, while those assigned to the inactive control condition did not complete any study tasks during this time. Mindfulness program sessions were hosted on the videoconference platform Webex. The same survey completed at baseline was completed again 1 week and 1 month following the intervention period, with added acceptability measures for those who took part in the FM and IM programs.

Results: Overall, the results did not differ as a function of NSSI history. A series of 3-way analyses of covariance revealed that both the FM and IM programs were effective at improving dispositional mindfulness (P<.001; ?p2=0.07), nonjudging (P=.03; ?p2=0.04), describing (P=.007; ?p2=0.05), well-being (P=.04; ?p2=0.03), and psychological need satisfaction (P=.005; ?p2=0.05) immediately after the program, with these improvements sustained 1 month later. Neither program resulted in improved awareness, nonreacting, observing, stress, emotion regulation styles, or academic engagement (all P>.05). Moreover, 3-way ANOVAs revealed high acceptability of both the FM and IM programs, with a preference for IM immediately after the program (P=.03; ?p2=0.03).

Conclusions: The findings of this study underscore the effectiveness and acceptability of the FM and IM programs to MBP in the university context, as well as the potential value of explicitly teaching and similarly emphasizing both FM and IM, an approach that may be optimally responsive to diverse needs and preferences among students.