Equipping young adolescents with wellbeing skills: does a universal, classroom-based CBT intervention promote positive mental health?


Poor mental health during adolescence has significant impacts and is associated with poor physical health, suicide, and self-harm (Zubrick et al., 2017). There is a need to develop interventions that promote positive mental health. One way of doing this is by enabling young adolescents to manage challenges and prevent the development of mental health difficulties.

Given that preventative interventions are offered en masse, schools are an ideal site for delivery as whole classes of adolescents can be targeted at once. Most of these interventions have tended to reduce mental health distress, for example, symptoms of depression or anxiety (Bastounis et al., 2016). However, not all have been effective in this aim (Kuyken et al., 2022).

However, it may be more appropriate to focus on promoting positive mental health, rather than reducing distress. One such intervention, process-based Cognitive Behaviour Therapy (CBT), developed by Martin O’Connor and colleagues in Dublin (2022) draws on key concepts from CBT including cognitive reappraisal and mindfulness. Sessions are 40 minutes long, and delivered weekly for 6 weeks, by school teachers trained to deliver them. Each classroom session includes an experiential exercise, a video, and individual and group activities. The focus of the current study was to evaluate this intervention.

Universal interventions designed to promote positive well-being in schools could be effective.

Universal interventions designed to promote positive well-being in schools could be effective.


To see if this intervention had the intended effects, O’Connor et al carried out a cluster randomised control trial. They recruited 29 elementary schools in Ireland to take part, each of which was randomly assigned to either the intervention (n=15) or the 12-week waitlist control (n=14). Within the schools, participants were pupils aged 10-13 years (Grades 5 & 6).

Participants completed self-report measures of positive mental health, resilience, mindfulness, and emotional literacy online, before the intervention, immediately after the intervention had finished, and at a 6-week follow-up. Participants also reported their satisfaction with the intervention.


In total, 604 students took part (44% of people invited), of which the majority were female (59.77%). 406 participants completed the intervention (or control) and measures at the 6-week follow-up; this means that around one in three did not complete follow-up measures, so we do not know if they benefit, or not. Significantly more participants dropped out of the intervention compared to the control group, however we do not know how many, as the authors have not stated that in the paper.

Reliability analyses of the content delivered in the intervention condition indicated very good agreement between the content delivered by teachers and the lesson plans. There were also encouraging findings in favour of the intervention from participants as they were satisfied with the intervention.

The authors were primarily interested in seeing whether those who received the intervention fared better in terms of ‘positive mental health’ than those who did not receive the intervention; they found that there were no significant differences between the groups (β=0.60, p=0.202). On the other outcomes of interest, the pattern of results was similar; there were no significant differences in the measures of resilience, mindfulness, or emotional literacy. When the authors specifically focused on those adolescents who were particularly struggling with their mental health (i.e., those with ‘languishing-to-moderate positive mental health’), those who received the intervention did make significant gains in mindfulness compared to those who did not receive the intervention.

The process-based CBT intervention did not improve well-being, but those struggling with their mental health did improve on mindfulness.

The process-based CBT intervention did not improve well-being, but those struggling with their mental health did improve on their mindfulness.


This study found that those young adolescents who received the process-based CBT intervention fared no better than those who did not receive the intervention on positive well-being overtime at up to 6-week follow-up. The same was true for resilience, emotional literacy, and mindfulness.

The only significant finding was that the intervention seemed to improve mindfulness in those adolescents who were struggling to begin with.

This process-based intervention, intentionally designed to promote positive well-being, was not found to be effective for early adolescents at the classroom level.

This process-based intervention, intentionally designed to promote positive well-being, was not found to be effective for early adolescents at the classroom level.

Strengths and limitations

Several aspects of this study are impressive; it was pre-registered on the public trials’ registry consistent with open science practices. Thorough training was provided to teaching staff to deliver session materials. There was good reliability between the session material and lesson plans meaning we can be confident that the intervention was delivered as intended.

However, there are some problems to highlight. Firstly, there is a disappointing lack of participants’ demographic information to enable us to contextualise the sample, such as ethnicity. It is not possible to tell whether marginalised groups were included in the study and/or engaged. This is important given that marginalised groups face significant barriers to accessing support for their mental health (Memon, 2016), thus universal, whole-class interventions in schools may be a useful way to access these populations and provide support. Secondly, and perhaps most concerningly, one-third of participants did not complete follow-up measures, and this was disproportionately so for participants in the intervention arm. It is not clear why, but it does beg the question of how the intervention was received and experienced. The authors reported that most participants were satisfied with the intervention, but this is based on those who completed post-intervention measures, rather than those who disengaged, meaning it is almost certainly positively skewed. Qualitative interviews post-intervention would have been helpful to understand how young people experienced the intervention and how it could be improved.

Furthermore, although the intervention was developed by an experienced clinical psychologist there was no consideration or inclusion of adolescents’ views on the content of the intervention. This is particularly relevant given the disengagement from completing study measures. Co-production is necessary to ensure the content and activities are practically viable and developmentally appropriate (Foulkes & Stapley, 2022).

The findings need to be interpreted with caution as a high proportion of participants did not complete the follow-up measures.

The findings need to be interpreted with caution as a high proportion of participants did not complete the follow-up measures.

Implications for practice

Given that one in six young people experienced a mental health problem in 2021 (NHS Digital, 2019), there is an urgent need to provide more mental health support and provision to this population. Schools offer an important environment for adolescents to learn and develop life skills, including those related to mental health. It may be that schools that were allocated to the ‘no intervention condition’ in the current study were already doing well in providing mental health promotion activities. Thus there was no additional benefit from O’Connor et al.’s (2022) intervention. Or it may be that we are still fundamentally unsure of how to effectively equip adolescents with these skills, and/or how and when to meaningfully measure outcomes to detect the benefits that these kinds of interventions have.

Currently, there is no “gold standard” intervention for adolescents. A vast array of mental health interventions in schools have been trialled such as CBT, mindfulness, and mental health education with mixed results (Nawaz & Cross 2021 on Clark et al., 2021). Unfortunately, the current study adds to this confusing and rather disappointing picture. However, it is interesting to note that the current study found improvements in mindfulness in adolescents with ‘languishing-to-moderate’ positive mental health, suggesting that targeting at-risk adolescents may be a more effective approach than all adolescents of a certain age.

This study may be a confirmation that we all need to go back to the drawing board. We need to gather all relevant stakeholders and consider our aims, hopes and ways to achieve the identification and evaluation of an effective intervention. Prevention means we are playing the long game; short-term benefits might be what is most feasible to evaluate as a researcher, who has an end date to their project, funding, or resources, but long-term gains are really what we are trying to achieve.

Although many interventions are available and have been trialled at schools, the support is mixed and the path ahead is still unclear.

Although many interventions are available and have been trialled in schools, the support is mixed and the path ahead is still unclear.

Statement of interests

No conflicts of interest with the study reviewed here. However, Emily Hards (EH) is funded by the Economic and Social Research Council (ESRC Post-Doctoral Fellowship). The views in this publication are her own and not necessarily the ESRC. Dr Maria Loades (Development and Skills Enhancement Award, 302367) is funded by the National Institute for Health Research (NIHR) for this research project with EH. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR, NHS, or the UK Department of Health and Social Care.


Primary paper

O’Connor M, O’Reilly G, Murphy E, Connaughton L, Hoctor E, McHugh L. Universal process-based CBT for positive mental health in early adolescence: A cluster randomized controlled trial. Behav Res Ther. 2022 Jul 1;154:104120.

Other references

Bastounis A, Callaghan P, Banerjee A, Michail M (2016). The effectiveness of the Penn Resiliency Programme (PRP) and its adapted versions in reducing depression and anxiety and improving explanatory style: A systematic review and meta-analysis. J Adolesc. 2016 52:37–48.

Chorpita, B. F., Yim, L., Moffitt, C., Umemoto, L. A., & Francis, S. E. (2000). Assessment of symptoms of DSM-IV anxiety and depression in children: A revised child anxiety and depression scale. Behaviour Research and Therapy, 2000 38(8), 835- 855.

Clarke, A., Sorgenfrei, M., Mulcahy, J., Davie, P., Friedrich, C. & McBride, T. (2021). Adolescent mental health: A systematic review on the effectiveness of school-based interventions. Early Intervention Foundation.

Foulkes, L., & Stapley, E. (2022). Want to improve school mental health interventions? Ask young people what they actually think. Journal of Philosophy of Education, 2022 56(1), 41–50.

Kuyken W, Ball S, Crane C, Ganguli P, Jones B, Montero-Marin J, et al. (2022). Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial. Evid Based Ment Health. 2022 ;25(3):99–109.

Memon, A., Taylor, K., Mohebati, L. M., Sundin, J., Cooper, M., Scanlon, T., & De Visser, R. (2016). Perceived barriers to accessing mental health services among black and minority ethnic (BME) communities: a qualitative study in Southeast England. BMJ Open. 2016; 6(11), e012337.

Nawaz, R. F., & Cross, L. School-based mental health interventions: reducing depression, anxiety and aggressive behaviour. The Mental Elf, 6 Oct 2021

NHS Digital. (2021). Mental Health of Children and Young People in England 2021- wave 2 follow up to the 2017 survey. 2021.

Zubrick SR, Hafekost J, Johnson SE, Sawyer MG, Patton G, Lawrence D. (2017). The continuity and duration of depression and its relationship to non-suicidal self-harm and suicidal ideation and behavior in adolescents 12–17. J Affect Disord 2017; 220:49–56.

Share on Facebook Tweet this on Twitter Share on LinkedIn Share on Google+
Mark as read
Create a personal elf note about this blog
Profile photo of Emily Hards

Emily Hards

Emily is a Lecturer and Post-Doctoral Research Fellow at the University of Bath. Emily, with the support of the Economic and Social Research Council (ESRC) will continue to develop her research over a 2 year period. She obtained her PhD from the University of Reading in 2019 and has since taught across undergraduate and postgraduate psychology programs. Her primary research interest is centred around self-evaluation i.e., how individuals view themselves across a range of mental health problems including depression, anxiety, and also among those young people with chronic illness. Emily is also interested in how self-evaluation is distorted in relation to eating disorders and those who self-harm. Her interests include loneliness and mental health in young people, adolescent mental health, in particular anything related to self-evaluation, and adolescent depression, and adolescent anxiety.

More posts

Follow me here –

Profile photo of Maria Loades

Maria Loades

Maria is a Reader in Clinical Psychology at the University of Bath, UK. Maria obtained her Doctorate in Clinical Psychology from the University of East Anglia in 2008. She has since worked clinically in the National Health Service across a variety of mental health settings, including community Child and Adolescent Mental Health Services (CAMHS) and a children’s inpatient unit. She completed a post-graduate diploma in cognitive behaviour therapy (CBT) for children, young people, and families at the Anna Freud Centre/University College London in 2013, and a Postgraduate Certificate in the Supervision of Applied Psychology Practice at the University of Oxford in 2015. Maria secured a prestigious NIHR doctoral research fellowship (2016-2022) to further her research into depression in adolescents, specifically those with chronic fatigue syndrome (CFS). She is currently funded by an NIHR Development and Skills Enhancement Award (2022-2023) in which she is developing her work into brief, scalable early help for adolescents with depression symptoms, and has established an informal research group at the University of Bath, spotLight on Adolescent Mood Problems (LAMP), with an embedded young person’s advisory group. Maria’s research interests include: Developing and delivering Cognitive and/or Behavioural treatments for young people with depression symptoms, including those with chronic illnesses, and those who may not otherwise access help; mental health literacy; therapist competence in delivering CBT, particularly in the field of child and adolescent mental health; and CBT supervision. 

More posts

Follow me here –