Mental health difficulties in children and young people (CYP) are rising, with one in five CYP reporting a probable mental health condition (Newlove-Delgado et al., 2022). Despite this, many CYP struggling with their mental health are unable to access mental health services in clinical settings due to lengthy waiting times, stigma and failure to meet criteria for referral (Shing et al., 2021). As a result, school-based interventions for the prevention and treatment of mental health conditions have been developed, implemented and evaluated.
Many studies have presented findings that support the use of school-based mental health interventions, such as a meta-analysis by Werner-Seidler et al. (2021; see Ariadna’s blog for an overview). However, evidence suggesting that school-based mental health interventions can lead to harm is also emerging. Specifically, both quantitative and qualitative studies have indicated that interventions that utilise the principles of cognitive behavioural therapy (CBT) and mindfulness can lead to elevated depressive symptoms, feelings of failure, and frustration (Bastounis et al., 2017; Miller et al., 2023; Stallard et al., 2013).
The present scoping review by Guzman-Holst and colleagues (2025) aimed to synthesise the existing literature outlining and explaining the potential harms of group school-based mental health interventions utilising CBT or mindfulness principles. Additionally, the review explored whether specific subgroups of CYP are susceptible to experiencing potential harm from school-based mental health interventions.

As clinical mental health interventions are difficult to access, school-based mental health interventions are being implemented to prevent and treat mental health difficulties in young people.
Methods
Eight databases were searched for controlled trials of school-based mental health interventions involving mindfulness and/or CBT. Unpublished works, book chapters and doctoral theses were also included. Studies were excluded if they were not exclusively mindfulness/CBT-focused, had a one-to-one format, did not have a control group, or had an active control group receiving another mental health intervention.
Titles and abstracts were independently screened by two researchers. One researcher independently conducted the full-text screening, with an additional researcher checking 10% of the papers. Inter-rater reliability for the full-text screening was high (k = .88). The Cochrane revised tool for risk of bias (RoB-2; Higgins et al., 2011) was used to assess the quality of the included studies. Characteristics of each study, intervention and negative outcome reported were then extracted.
Results
Study characteristics
Out of 112 intervention trials included in the scoping review, 11 studies on 10 intervention trials (8.93%) reported negative outcomes. These 10 studies included participants with mean ages between 12 and 16 years old, with samples sizes from 127 to 8,376 participants. All studies were randomised controlled trials (RCTs) based in high-income countries, and assessed universal interventions, meaning that all the interventions were delivered to whole classes of students. Six interventions used CBT techniques and four used mindfulness. In the quality assessment, five out of the 11 studies were rated as high quality (45.5%), four were rated as moderate quality (36.4%) and two were rated as low quality (18.2%).
Potential harms
A range of negative mental health outcomes followed the school-based interventions, including increases in internalising symptoms and negative cognitions typical of depression and anxiety. Hyperactivity, inattention and impulsivity was also found to increase in some studies, as well as negative outcomes linked to mindfulness and prosocial behaviour. Only three out of the 112 (2.68%) studies reported adverse events (e.g., self-harm), but none of the events were linked to the intervention. Half of the 112 included studies reported positive effects of the interventions.
Intriguingly, negative outcomes were more likely to be reported following an intervention in higher-quality studies. One third of studies with a low risk of bias reported negative outcomes, which is a considerably higher proportion than out of all included studies regardless of risk of bias (8.93%).
Subgroups
Negative outcomes were more likely to be reported by participants who received the intervention and were male, younger, received free school meals, had higher baseline symptoms and subclinical levels of depression in comparison to the same subgroup in the control condition. 55% of the 11 studies reported negative outcomes in a subgroup analysis, meaning that these specific subgroups are notable populations that should be the focus of future research on the harms of school-based interventions.
Explanations for harms
There was generally a lack of exploration into the mechanisms underlying a direct relationship between school-based mental health interventions and harm, with many studies looking to school, programme or participant-level factors. This includes the amount of training received by school staff to deliver the intervention with fidelity (Kuyken et al., 2022; Montero-Marin et al., 2022), the length of the intervention (Stoppelbein, 2003), and the engagement levels of participants (Stallard et al., 2012).

“Teaching mental health lessons to all young people might not always be appropriate as it could lead to potential harm.”
Conclusions
Although potential harms were only found for a minority of studies testing universal school-based mental health interventions, the effectiveness of universal interventions in improving CYP’s mental health remains questionable, with only half of the studies included in this review reporting positive effects.
It could be argued that using classroom-based strategies to improve and raise awareness of CYP’s mental health is not effective for both those with and without mental health difficulties, as it is inadequate in addressing their needs or viewed as unnecessary. As a result, other formats of school-based mental health interventions, such as targeted interventions, should be explored to evaluate whether they result in fewer negative outcomes.

Guzman-Holst et al. (2025) suggest that triaging young people into targeted school-based mental health interventions, which can be tailored to support individual needs, could be an alternative approach to universal interventions.
Strengths and limitations
This scoping review has many methodological strengths, including a comprehensive search strategy which was clearly outlined, and high inter-rater reliability between reviewers assessing the eligibility of the studies. This increases the likelihood that this review included all relevant studies in this research area.
However, this review did not include any interventions specifically adapted to subgroups of CYP in need, such as neurodivergent CYP or refugees. Assessing potential harms of school-based interventions for these subgroups is important, as they are more likely to develop mental health difficulties than the general population (Hameed et al., 2018; Kerns et al., 2020). As subgroup analyses were found to be important in this review, it is crucial to examine the outcomes of school-based interventions in additional subgroups.
Furthermore, this study limited its scope to in-person CBT and mindfulness-based interventions, which excludes online and adapted interventions (e.g., for those who have experienced trauma). It is important to explore whether online and adapted interventions lead to potential harms, as they become an increasingly prevalent option for supporting CYPs with their mental health within and outside of school (El-Khodary & Samara, 2020; Eschenbeck et al., 2019; Zhou et al., 2021).
It is important to note that while these results may be generalisable to 12–16-year-olds from the UK who receive a universal school-based mental health intervention, they cannot be generalised for younger and older children, those with special educational needs or neurodiversity, and those receiving targeted interventions.
Finally, this review was only a scoping review rather than a systematic review or meta-analysis, meaning that pooled statistics from the studies could not be analysed, and average effect sizes cannot be commented on. In future studies, it would be beneficial to estimate the overall negative effect of school-based mental health interventions so the extent of harm caused across different interventions can be quantified.

It has yet to be explored whether school-based mental health interventions delivered online or adapted for specific groups of young people also produce negative outcomes.
Implications for practice
This scoping review highlights the importance of practitioners evaluating the benefit-harm ratio of delivering universal school-based mental health interventions, informed by empirical evidence. As some studies have found that universal interventions can lead to negative outcomes, researchers and practitioners need to be confident that the benefits of an intervention outweigh any potential harms before implementing the intervention. This should be considered alongside the needs of the specific school population and individuals who are most at-risk for mental health difficulties.
Furthermore, there is a possibility that negative outcomes are underreported in the current evidence base, considering that higher quality studies in this review were more likely to report a negative outcome. CYP may also underreport adverse events such as self-harm due to the stigma surrounding these events (Mars et al., 2016; Waller et al., 2023). Therefore, future research on school-based mental health interventions should ensure negative outcomes are measured and sensitively encourage CYP to report any adverse events if they experience any following the intervention. This will help to more accurately establish the prevalence of potential harms and untangle their relationship with school-based interventions.
Negative outcomes could reflect the disadvantages of using a one-size-fits-all approach which is typical of universal interventions. This explanation is supported by Stallard et al. (2012), who proposes that CBT interventions delivered in classrooms or group settings may be unable to support those most in need. Thus, the symptoms of those in need of targeted support may have worsened over the course of the universal intervention. Furthermore, universal interventions may be viewed as irrelevant or frustrating to those who feel that they do not require mental health support (Miller et al., 2023). It would be interesting to explore whether targeted interventions and other whole-school approaches to wellbeing, such as social emotional learning, are effective in supporting CYP’s mental health, and whether they lead to the same extent of negative outcomes as universal interventions. The authors emphasise the importance of retaining the autonomy of CYP in deciding whether they receive a mental health intervention, and what type of intervention they receive. Targeted interventions may better respect this autonomy and an individual’s needs, as opposed to a one-size-fits-all approach to all children in the classroom.
Ultimately, it is difficult to judge whether and why universal school-based mental health interventions are harmful, based on the current evidence. Therefore, it is crucial that further research is conducted examining explanations for potential harms, including qualitative studies exploring the experiences of CYP who have received a school-based intervention.

It is important for researchers and practitioners to weigh up the benefits and harms of universal mental health interventions before they are implemented in schools.
Statement of interests
The author of this blog is currently involved in a separate research study examining the effectiveness of targeted school-based mental health interventions.
Links
Primary paper
Guzman‐Holst, C., Davis, R. S., Andrews, J. L., & Foulkes, L. (2025). Scoping review: potential harm from school‐based group mental health interventions. Child and Adolescent Mental Health, 2025.
Other references
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El-Khodary, B., & Samara, M. (2020). Effectiveness of a School-Based Intervention on the Students’ Mental Health After Exposure to War-Related Trauma. Frontiers in Psychiatry, 2020 10.
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