The prevalence of mental health problems is estimated at almost 14% among individuals aged 15-19 years, representing the highest rate across all age groups up to 24 years [1]. According to the Global Burden of Disease study by the Institute for Health Metrics and Evaluation (IHME), anxiety and depression account for approximately 40% of these cases [2]. Adolescents with anxiety or depression often experience persistent sadness, irritability, low energy, or hopelessness [3-7], which can lead to social withdrawal, school avoidance, poor academic performance, and various health-related challenges [8-11]. When such difficulties occur during adolescence, a period of critical developmental changes, including identity formation, emotional regulation, and evolving social relationships [12-18], they can negatively shape future well-being. Without appropriate support, these challenges may persist into adult life, negatively affecting employment opportunities, interpersonal relationships, and overall quality of life [19-25].

Early intervention is essential, both to prevent the worsening of symptoms and to reach young people during a critical developmental stage, particularly as an increasing number of adolescents are experiencing anxiety and depression [26-30]. However, public mental health services frequently involve long waiting times [31,32]. In the United Kingdom at the end of 2023, only about one-third of adolescents with referrals to Child and Adolescent Mental Health Services (CAMHS) were able to access support within a year [33]. These delays highlight a gap between the growing demand for mental health services and the limited capacity of available professionals [34], creating barriers to accessing care. This problem can disproportionately affect individuals from ethnic minority groups or disadvantaged socioeconomic backgrounds, who may be more likely to experience such mental health difficulties [35,36]. Digital mental health interventions offer a promising avenue to bridge this gap, reduce inequalities, and deliver timely, accessible support to those who need it most.

The widespread use of digital devices, with as many as 96.5% of young people aged 12-17 years owning a smartphone in the United Kingdom [37], has paved the way for new approaches to delivering mental health support. Among these, digital interventions have emerged as valuable tools for helping young people manage anxiety, depression, and other mental health challenges [38]. Such tools can further offer the privacy, convenience, and flexibility that many young people seek [39-41], making mental health support more accessible. In addition to meeting the needs of young people, digital mental health interventions also offer a cost-effective approach [42] that could help alleviate the burden on mental health services by complementing existing care. By improving mental health literacy, these tools can also equip adolescents with skills required to better manage their symptoms and recognize when to seek professional help [43,44].

A wide range of digital mental health interventions has been developed in recent years, including those targeting anxiety and depression in adolescents [45-49]. These interventions are primarily delivered through mobile apps (eg, We Click [UNSW Sydney Brain Sciences] [50], CARE [Child and Adolescent Research in Emotion Lab] [51], and MoodHwb [Cardiff University] [52]), websites (eg, Grasping the Opportunity [53], An Enhanced Psychological Mindset Session [54], and MoodGYM [55]), or online platforms (eg, BetterHelp and Thriveworks). They draw on a variety of theoretical frameworks, such as positive psychology (eg, Bite Back [Black Dog Institute] [56]), mindfulness (eg, CARE [51], Tita [University of Turku] [57]), and growth mindset (eg, Project YES [Youth Empowerment & Support; Lab for Scalable Mental Health and Koko] [58] and Shamiri [Shamiri Institute] [59]), among others, but cognitive behavioral therapy (CBT; eg, Stressbusters [team from Manchester, The Institute of Psychiatry, London and Australia] [60], CATCH-IT [Competent Adulthood Transition with Cognitive Behavioral, Humanistic, and Interpersonal Training; University of Chicago] [61], and SPARX [The University of Auckland] [62]) remains the most commonly used framework. Digital interventions can address a broad spectrum of mental health challenges, such as eating disorders [63], posttraumatic stress symptoms [64], or sleep problems [65,66]. Some tools are intended for individuals with neurodevelopmental disorders [67] or chronic diseases [68], whereas others are aimed at the general population or at individuals experiencing elevated symptoms, as a form of prevention [69] or early support [70]. Some serve as a medium for delivering conventional therapy [71] or are designed to complement traditional approaches by offering additional resources or activities between sessions (eg, ChilledOut Online [Macquarie University] [72]), whereas others are intended to function independently, without direct support from a mental health professional [73].

Despite the growing number of such interventions, there remains a significant gap between their development, rigorous evaluation, and application in real-world settings. While many digital mental health interventions are publicly accessible, a substantial number have not undergone empirical evaluation [45,74,75], raising concerns about their effectiveness and safety. At the same time, few digital interventions targeting anxiety and depression that have been evaluated in research studies are actually implemented or widely accessible outside research settings [69,73,76]. Additionally, such interventions are still seldom developed with the involvement of the target population, which may limit their effectiveness [77-80]. This highlights a need for co-designed, practical interventions that are both evidence-based and accessible to adolescents beyond controlled research environments.

While assessing the effectiveness of an intervention is crucial, the success of digital mental health interventions also depends on how adolescents engage with them in real-world contexts. Even the most well-designed tools can fall short if they fail to capture users’ attention, meet their needs, or resonate with their lived experiences. Research has shown that adolescents often disengage from digital interventions due to issues such as limited interactivity, concerns about privacy, or unclear and unrelatable content [81-83]. Engagement itself is a complex construct that goes beyond simple metrics such as usage frequency or duration. It is important that user interactions with the intervention are meaningful and sufficient to support positive behavior change [84]. Therefore, investigating targeted user experiences with the interventions is essential to ensure that digital mental health interventions are effectively engaging and consequently beneficial for those experiencing mental health difficulties [85].

Existing qualitative evidence has highlighted that adolescents value interventions that feel relevant to their age, culture, and experiences [81-83,86,87]. Interactive and personalized features, ease of use, privacy, flexibility, and confidentiality further support engagement with interventions [82,83,87,88]. Concerns about privacy and perceptions that interventions are overly text-heavy or too clinical have been identified as barriers to engagement [82,89]. This supports the view that qualitative research plays a vital role in understanding adolescents’ experiences and perspectives on digital mental health interventions. User feedback obtained through qualitative methods helps ensure that interventions remain engaging, relevant, and responsive to the specific needs of adolescents [90]. Thus, understanding individual perspectives can provide deeper insights into what makes digital interventions acceptable, meaningful, and helpful, and further inform the refinement of intervention content and design beyond what quantitative measures alone can capture.

This qualitative study aimed to examine young people’s views and experiences of 2 distinct digital mental health interventions (Bite Back [56] and Project YES [58]) designed to address anxiety and depressive symptoms. Both interventions were used as reference points for adolescents and were not directly compared to one another because they differ considerably in design and content. The study explores key factors that influence how young people in the United Kingdom interact with these interventions, including specific features and content they may find beneficial or unhelpful, their preferences, and perceived usefulness and effectiveness. By examining the views of users who differ slightly in age and culture from the original target user population, this study seeks to contribute to our understanding of potential barriers to implementation and the need for adaptation of user-centered digital mental health interventions, supporting efforts to enhance their accessibility, relevance, and impact for a wider range of young people.

This study was guided by the following research questions: (1) What are the barriers and facilitators to engagement with 2 distinct interventions (Bite Back and Project YES) among UK users aged 16-19 years? (2) What are young people’s preferred design features and content when comparing Bite Back and Project YES? (3) What are young people’s perceptions of the potential usefulness and helpfulness of Bite Back and Project YES for their mental health?

Ethical approval was granted by the University of Bristol ethics board (reference number 21829), and the qualitative study protocol was registered on the Open Science Framework (OSF) [91]. This paper adhered to the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist [92].

This qualitative study explored participants’ experiences of 2 distinct mental health interventions through 1-hour semistructured online interviews, analyzed using pragmatic thematic analysis. Adolescents aged 16-19 years living in the United Kingdom, with access to a smartphone or laptop and an internet connection, were eligible to take part in the study. Twenty-two adolescents aged 18-19 years were included in the final sample. Those who reported experiencing mental health symptoms that severely impacted their lives or who had ever been hospitalized due to mental health–related reasons were excluded from the study. These criteria were chosen primarily to complement the “Sleep Well” study, which recruited a nonclinical sample of mostly 16-18-year-olds. This age range was slightly expanded to include young people just above the age range in which Bite Back and Project YES had previously been evaluated, to explore how these interventions were experienced by slightly older adolescents.

Convenience sampling was implemented due to recruitment challenges, and as a result, purposive sampling based on age and ethnicity was not feasible. Most recruitment was facilitated through a university’s experimental-hours scheme, through which psychology students can earn course credit for participation in research. Five mental health charities working with adolescents were approached; only 1 agreed to assist with recruitment, while the remaining charities were unavailable. Interested adolescents first completed an online eligibility questionnaire. Those who met the inclusion criteria were invited to a brief video call with the researcher (via Microsoft Teams). During this call, which was not recorded, participants verified their nationality and age by presenting a valid photo ID. Eligible participants then received a Qualtrics (Qualtrics International Inc) link to the consent form and additional well-being, anxiety, and depression questionnaires. No relationship with participants was established prior to the start of the study. Participants received a £20 (£1=US $1.26 as of March 2025) Love2shop voucher or 2 experimental hours credits to compensate them for their time spent using the interventions and participating in the interview.

Participants provided consent and completed questionnaires (see Standardized Measures section) before they gained access to the interventions. They were then invited to engage with Bite Back and Project YES for a total of approximately 1 hour (30 minutes with each intervention) over a 2-week period, in the order they preferred. This duration was chosen to ensure that all participants had comparable exposure to both interventions while taking into account their academic commitments and the single 30-minute-session design of Project YES. As both interventions were freely available external programs, the actual time spent using the interventions was not formally tracked. Following this 2-week period, participants took part in a 1-hour, semistructured online interview that explored their views and preferences regarding these interventions.

To determine a sample size for this study, the concept of “information power” was applied [93]. This study incorporates relatively narrow aims and a fairly specific sample, focusing on UK adolescents aged 16-19 years and their views and experiences of 2 distinct digital mental health interventions. However, the use of convenience and purposive sampling to recruit participants may limit how targeted the sample could be. In addition, the study is not guided by a single established theoretical framework. Although the data were generated through 1-hour semistructured interviews that support rich interview data, both PK and MC were novice interviewers with some prior interviewing experience. Inductive thematic analysis is used to identify patterns across participants’ accounts. Taken together, these factors indicate that a sample size of 20 participants was considered adequate to provide the necessary information power to fully address the research questions.

Bite Back and Project YES were chosen through a systematic review [73] that was conducted as part of the “Sleep Well” study (ISRCTN14480620) [94], which focused on creating stepped care that aimed to help adolescents with their sleep, anxiety, and depressive symptoms. Within this review, both Bite Back and Project YES were identified as promising interventions based on effectiveness, risk of bias, and real-world applicability, and were the only freely available options in this category [73]. This evaluation was conducted independently, with none of the authors having any investment in either intervention.

An inductive thematic analysis [103] using a pragmatic epistemological approach was adopted, allowing the researcher to actively construct themes from qualitative data while ensuring that the findings reflected participants’ perspectives without using a preexisting framework. The themes remained closely grounded in participants’ views and experiences and, consistent with a pragmatic approach, focused on findings of practical relevance for intervention development and improvement. Data analysis was conducted independently by the primary researcher (PK), who had prior training in qualitative research methods. All authors were involved in discussing and refining the coding framework to enhance the credibility of the findings. The process followed the step-by-step approach to thematic analysis outlined by Braun and Clarke [103]. This involved familiarization with the transcripts, development of initial codes, and an iterative process of grouping and refining patterns across the dataset until the final themes were established. NVivo (Lumivero) software was used to manage the data [104].

As a researcher with a background in psychology and an interest in improving young people’s mental health, the primary researcher (PK) approached this study with a strong belief in the potential benefits of digital interventions. While PK had no affiliations with the digital mental health tools studied in this project, her personal interests may have influenced how she interpreted participants’ experiences, particularly if she unintentionally elicited or prioritized positive feedback. PK strove to balance her personal interest in improving mental health with an open-minded approach to understanding young people’s views and preferences. The potential influence of the researcher’s positionality, prior assumptions, and values about the topic was addressed through ongoing reflection, grounding interpretations in the interview data, and actively looking for examples that did not fit the developing patterns.

The results are based on 22 interviews. Most participants were White (n=16, 73%), 5 (23%) identified as Asian or Asian British, and one (5%) identified as having a mixed ethnic background. Participants were either 18 years old (n=8, 36%) or 19 years old (n=14, 64%). The majority were women (n=18, 82%), and most had no prior experience with online mental health interventions (n=15, 68%). Almost all participants had low-severity scores for depression (n=19, 86%), anxiety (n=20, 91%), and total RCADS-25 (n=19, 86%) scores, indicating that symptom levels were within the nonclinical range. Participants’ mean SWEMWBS score was 23.35 (SD 3.13), with higher scores indicating more positive mental well-being [105]. Detailed participant characteristics are presented in Table 1.

Relatability refers to whether participants felt that the interventions were relevant to their age, personal experiences, and the cultural references used within the content. Interventions targeted at younger audiences, those containing culturally mismatched information, or those failing to reflect participants’ lived experiences could affect young people’s engagement. See Figure 1 for an overview of all identified themes.

Participants frequently reflected on whether the tone, language, and content of the interventions felt appropriate for their stage of life. Many felt that some parts were targeted toward a younger audience, such as secondary school students. They reported that the information was overly simplified or that the language felt too basic. While most participants found this off-putting, others appreciated content that was accessible, clear, and welcoming to a range of age groups. A few described how more complex or mature content would have made it feel more suitable for them and encouraged them to continue using the intervention.

Familiarity with cultural references also influenced how relatable participants found the interventions. Some individuals found it difficult to connect with content that included Australian or US-based brands, examples, or language rather than references that felt familiar within a UK context. However, not all participants mentioned such cultural discrepancies.

Some participants indicated that other people’s experiences made the intervention feel more personal. However, others pointed out that, although the stories felt like a valuable component of the intervention, they became less impactful when unrelated to their current stage of life.

Some participants queried the inclusion of questionnaires at the beginning of the interventions. They expressed uncertainty about their purpose and how, or whether, the responses were used. For these participants, the questionnaires felt unnecessary and uninformative. Although questionnaires in both interventions were not used for tailoring, Bite Back users received some feedback depending on their scores, which some participants valued. However, most participants did not question the relevance of these questionnaires.

Transparency relates to the clarity of instructions, openness about participants’ data use, and the reliability of the interventions’ content. A lack of clarity around what the tasks involved or where participants’ information was going could affect adolescents’ willingness to fully engage with the interventions.

A few participants highlighted that the statistical content provided in Project YES made the information feel more legitimate and helpful. This was the only aspect of either intervention that participants specifically identified as contributing to a sense of reliability.

Several participants expressed uncertainty about what would happen to the information they shared. Some felt uneasy when the intervention did not clearly explain how their responses would be used or stored. This lack of clarity could lead to discomfort, which might act as a potential barrier to engagement.

A few participants suggested that clearer guidance on how to begin and navigate the interventions would be helpful. They described moments of uncertainty about how to start tasks or move through sessions. These suggestions highlight the importance of having explicit, well-structured instructions to support smoother engagement.

Design and usability refer to the structure, presentation, and navigation of the interventions. Adolescents commented on the visual appeal, clarity of layout, and how easy it was to use and understand the content. A user-friendly layout, inviting appearance, and clarity of delivery could influence how adolescents interacted with the interventions.

Participants addressed the tone and presentation of the interventions. Bite Back was generally described as inviting, welcoming, and engaging, while Project YES was occasionally seen as more like a formal survey or test. Some participants who described feeling this way about Project YES also noted that it made them feel bored. A welcoming and well-structured website may influence the level of user participation.

Participants commented on the formatting and structure of the interventions. Bite Back was described by some as professional and well-designed. A few participants noted that the weekly format and content organized in smaller chunks made the sessions feel shorter and easier to follow. A few also noted that the weekly format made it easy to forget about the intervention. One participant said they would have preferred that the content take up more space on the screen.

In contrast, participants described Project YES as having a simpler design. Some said the platform was not user-friendly and mentioned that scrolling through pages was a long process. The presentation was occasionally compared to a textbook or “Wikipedia” page, and some felt that the large number of slides with minimal information elongated the experience. Suggestions included reducing the amount of text and making it more interactive.

Both interventions were described by many participants as easy to use. Bite Back was reported as having clear instructions, a straightforward interface, and short, accessible activities. Some said it was easy to start using and to return to the page if they had to leave. However, a few participants mentioned that logging back in required effort, and one noted that signing up took time. Others described needing to refresh the website or listen again to audio to be able to move to the next week’s session when the connection was lost.

Several participants said Project YES was easy to start using because no login was required, and some described the interface as clear and the navigation as straightforward. Others, however, said it was less easy to use, with one reporting difficulty navigating through the sessions and another stating it took more effort to use than Bite Back. A few participants also mentioned that getting through the sessions was a long process. Difficulties with logging in or navigating could create barriers to participants’ engagement with the interventions.

Visual elements such as colors, fonts, and images contributed to how appealing and approachable the interventions felt. Participants described the colors and variety of fonts as uplifting and inviting. Images, especially cartoons or symbolic visuals, were positively received when they complemented the session content.

Participants expressed mixed views on the content of both interventions. Some described the content in both interventions as familiar or “common sense,” reporting that it often felt like a repetition of information they already knew. While a few participants found this repetitive or not educational, others appreciated the opportunity to revisit known material and considered it a helpful reminder. Several participants mentioned that the concepts were explained using simple language. For some, this contributed to perceptions that the content was overly simplified or infantilizing. However, there were some participants who valued the inclusion of psychological concepts that were explained simply or described the content as scientific.

Autonomy and personalization refer to features that allow participants the freedom of choice, control, and flexibility within the interventions. Participants referred to existing features such as selecting sessions, receiving feedback, and viewing progress. Suggestions to save progress and comments on format preferences reflected a desire for greater control over when and how they interact with the material.

Most participants liked or were positively surprised by the feature that allowed them to choose which session to work on in Project YES. Some said that having this choice made the intervention feel more tailored to them.

Participants described the use of scores and ratings in Bite Back as a reflective and engaging feature. Several reported that receiving a score helped them learn more about themselves, visualize their progress, or feel more motivated to continue. Questions were generally viewed as clear, age-appropriate, and easy to use. However, one participant noted that receiving a low score could potentially be demotivating for some users.

Participants referred to Bite Back’s progress bar as a feature that helped them track their progress through a session. While not all participants mentioned it, those who did described it as helpful and motivating. Some said it gave a clear sense of progression and an end point to work toward. A few mentioned missing a similar feature in Project YES.

Some participants suggested that the ability to save their responses to tasks could improve their experience with the interventions. A few mentioned that it would be helpful to revisit previous answers as a way to reflect on or recall how they felt at a particular time.

Participants expressed varied preferences for how information was delivered. Some preferred reading text over listening to audio or watching videos, noting that reading was quicker, easier to process, or better suited to their learning style. However, many participants appreciated having multiple formats available, such as audio, video, and text, and described this as helpful or accessible. The ability to revisit the same content in different formats, such as having text that repeated video content, was seen by some as useful, while others felt that such repetition should be avoided. Several participants mentioned that bullet points would make the text easier to follow, particularly if they missed parts of a video.

Patterns of engagement describe how participants interacted with the interventions over time. This theme includes when and how they used the content, which sessions they continued with or disengaged from, and how they perceived the interventions in terms of accessibility and commitment.

Participants described varying patterns in when and how long they engaged with the interventions. Some completed multiple sessions in one sitting, often influenced by having free time or wanting a distraction. Others reported using the interventions in response to specific emotional states, such as feeling stressed, down, or frustrated. The time spent on each session ranged from 20 to 40 minutes, which many participants viewed as an appropriate or optimal duration. A few appreciated the short and manageable structure of both interventions.

Participants noted that not all sessions were equally appealing, and some expressed a desire for more flexibility in how they moved through the interventions, as this influenced how far they progressed. Several mentioned wanting to skip sessions they found less engaging, particularly the mindfulness session in Bite Back, which was sometimes seen as requiring a specific mindset. A few participants reported stopping their use of the intervention when they reached this session, suggesting that being unable to move past less preferred content could discourage continued engagement.

A few participants described the interventions as low-commitment or a more accessible alternative to more formal support services, such as university counseling.

Interactive and motivational elements refer to intervention features that could encourage engagement and support a more active experience. This theme includes both the elements present in Bite Back and Project YES, as well as participants’ suggestions for enhancing interactivity and motivation. It encompasses subthemes such as the unlocking feature, activities, gamification, an app version, and notifications.

Participants expressed mixed views about the unlocking structure of sessions in Bite Back. Several described it as motivating, noting that progressing through the weeks felt like achieving small goals or even like playing a game. Some said it encouraged consistency and ensured they moved through the content gradually. However, a few participants preferred having all sessions available from the start so they could choose content most relevant to them. One participant noted that the unlocking structure shortened their time spent using the intervention.

Participants expressed a range of views about the activities included in both interventions. Many found the interactive components engaging and reflective, with some describing them as encouraging deeper thinking about personal experiences or relationships. Activities involving giving advice were often highlighted as particularly engaging and meaningful, though a few participants noted that these tasks could feel irrelevant when based on scenarios they had not personally experienced. In Bite Back, short, varied activities were generally well received, with participants appreciating their manageable length and real-life applicability. In contrast, some participants felt the tasks in Project YES became repetitive, overly focused on writing, or difficult to complete. Suggestions included incorporating a greater variety of scenarios and making the tasks more general so that more people could relate to them.

Some participants suggested that incorporating game-like features could make the interventions more engaging. One participant said that receiving a reward at the end of a session would feel motivating and similar to playing a game.

Several participants suggested that having access to the interventions through a dedicated mobile app would improve convenience and usability. An app-based format was seen as a way to encourage more consistent use by reducing barriers such as having to log in via a browser or remembering to return to the website after taking a break.

Most participants identified notifications as a potentially helpful feature for supporting consistent engagement with the interventions. They suggested that reminders could encourage them to return to the platform regularly, helping them stay on track with sessions and avoid forgetting about the program over time.

Perceptions of usefulness capture participants’ reflections on how the interventions supported their mental health and well-being. Adolescents discussed overall helpfulness, impact on mood, and how the interventions encouraged positive habits.

Most participants perceived Bite Back as more helpful than Project YES. Many said they would be willing to recommend it to younger friends or family members. However, there were some participants who found Project YES beneficial, while others felt that both interventions offered useful elements. A few expressed a desire to revisit Bite Back to explore additional sessions.

Several participants mentioned that using Bite Back made them feel calmer and more positive afterward and indicated that the intervention was a good starting point for improving their well-being. Some also reported positive changes after using Project YES.

When recommending Bite Back to others, some participants emphasized its potential to support the development of positive daily habits, even though not all reported forming these habits themselves.

This qualitative study used 2 distinct and widely available digital mental health platforms (Bite Back and Project YES) to help understand what supports or hinders young people’s engagement, what design features they prefer, and how useful they find these interventions. Participants frequently reflected on whether the tone, language, and content of the interventions felt age-appropriate, culturally relevant, and connected to their personal experiences. Clarity of instructions, transparency around data use, ease of navigation, and flexibility in how the interventions could be used also appeared to influence engagement. Participants generally preferred features that were interactive, visually engaging, and personalized, and many valued being able to track progress or choose content. Bite Back was often described as helpful, although some participants also found Project YES beneficial and identified useful elements in both interventions. These findings highlight a number of factors that may influence how young people engage with and perceive digital mental health interventions.

Facilitators and barriers to engagement were shaped by multiple, interconnected factors. Relatability and transparency were among these, with participants preferring interventions that used culturally relevant, age-appropriate content that aligned with their stage of life, supporting previous research emphasizing the value of content that resonates with adolescents’ lived experiences [81-83,86,87]. It is important to note that although participants in this qualitative study were only slightly older than the intended user age group, many described the content and design of both interventions as age-inappropriate. This indicates that even small age differences may affect perceived relevance and adds to existing research showing that developmental stage matters in digital mental health intervention design [106,107]. This highlights the need to involve young people across different adolescent age ranges in intervention development, especially when designing interventions targeting broader age groups. Although tailoring content to very narrow age bands may enhance relevance, this is not always practical in real-world settings. A more feasible approach may involve developing interventions that are adaptable to different developmental stages. In the future, artificial intelligence may offer scalable ways to personalize content dynamically based on age, preferences, or individual needs. Transparency regarding the purpose of the interventions, confidentiality, and instructions was of particular importance to participants, supporting previous research identifying transparency as a key factor in building trust and engagement [81]. Participants expressed a need for clear explanations on what happens to their data, how they could benefit from such interventions, and the purpose of certain tasks. The way transparency is communicated could matter, while clear information might foster trust, overly detailed or complex explanations might be overwhelming and may conversely hinder engagement. This suggests that interventions should balance providing essential information in a clear and accessible manner while avoiding information overload, ensuring young people feel informed and confident in engaging with digital mental health interventions.

Autonomy and personalization, patterns of engagement, and interactive and motivational elements were also identified as important factors influencing engagement, further aligning with previous research demonstrating their role in supporting young people’s use of digital mental health interventions. Participants valued the ability to track their progress and choose the order or type of content they engaged with [82,87], supporting a sense of control and relevance. Patterns of engagement indicated a general preference for shorter sessions [82,83,87], with some participants expressing that digital mental health interventions felt less demanding and required less commitment than student counseling services. Most participants engaged with the interventions only once without returning, describing differences in motivation for when to use them, which was often shaped by their mood, available time, or daily routines. This highlights the need for interventions to allow flexible use that aligns with adolescents’ lives, in line with broader research showing that ease of access and fit with everyday routines can influence how young people engage with digital mental health platforms [82,83,86,87,108]. Some participants suggested that the existing feature of session unlocking could help sustain motivation and recommended additional elements such as gamification, a mobile app version, or notification reminders to further encourage uptake and engagement. However, preferences varied, with some participants expressing the need for notifications as reminders and an app version for ease of access. Some participants preferred having all sessions unlocked to be able to choose those that were most appropriate for them, which is consistent with findings from the broader literature [82]. This reflects the importance of offering customizable interactive features to cater to individual preferences.

Participants preferred design features and content that offered clear and simple information, were easy to navigate, and featured a colorful, pleasing appearance. The ability to choose the order of sessions and to track progress was valued [82,87], which might have provided a sense of control and accomplishment. Informative content was appreciated, particularly when it was available in various formats, such as text, audio, or video, allowing participants to engage with material in ways that suited their preferences. These findings indicate that visually pleasing design, flexible use, and access to content in multiple formats are valued by young people and may further influence their engagement with digital mental health interventions. This is consistent with broader mHealth design research, which highlights navigation, presentation of information, personalization, and aesthetics as features associated with stronger user engagement [109].

Participants described the interventions as grounding and as a good starting point for improving well-being, with some expressing willingness to revisit them in the future. Participants’ views on the usefulness of the interventions suggest that even when an intervention includes therapeutic, evidence-based content, this may not be enough on its own for young people to find it helpful. This aligns with previous qualitative research highlighting the importance of perceived usefulness in sustaining young people’s engagement with digital mental health interventions [81,108].

All themes identified in this study are interconnected and collectively may shape how young people engage with digital mental health interventions and what they perceive as helpful within them. Design features and content preferences may influence whether young people find interventions appealing, practical, and worth returning to, which in turn may affect how much they benefit from using them. This highlights the importance of involving the target group in intervention development to ensure that interventions reflect young people’s needs and preferences. Overall, the findings support a broader body of research suggesting that helpfulness and engagement are shaped not only by intervention content, but also by whether digital mental health tools feel relevant, easy to use, and trustworthy to young people in practice [110].

The use of a think-aloud component in an interview setting is a relatively novel approach and was generally perceived as a helpful technique for aiding recall and encouraging reflection on the interventions. Most participants noted that the prompts made it easier to remember and discuss specific aspects they might have otherwise overlooked, which could have enhanced the depth of feedback they provided. However, some participants found it challenging, suggesting that while think-aloud can enrich data collection, it should be introduced carefully to ensure participants feel comfortable sharing their perspectives.

Convenience sampling resulted in a participant pool that primarily consisted of university-educated individuals, including psychology students, who did not have elevated anxiety or depression and who might have greater familiarity with mental health concepts and digital tools, potentially shaping their perspectives. Although the study initially intended to use purposive sampling based on age and ethnicity, recruitment challenges contributed to the limited participation of individuals aged 16-17 years. As a result, 16-17-year-olds were not represented in the final sample, which meant that potential age-related differences in preferences and engagement with digital mental health interventions could not be explored. This is particularly relevant as the examined interventions have been evaluated with slightly younger adolescents (Bite Back for aged 12-18 years, Project YES for aged 11-17 years), which may have influenced how participants perceived and interacted with the content. Furthermore, as the interventions were designed to support young people experiencing symptoms of anxiety or depression, our participants’ generally low symptom levels may have affected how useful they found these interventions.

Participants were asked to use each intervention for approximately 30 minutes over a 2-week period. This decision was made to ensure consistency in the amount of time participants spent using each intervention, as Project YES was designed to be completed in a single 30-minute session, while also accommodating participants’ academic schedules. While this approach allowed participants to experience and compare both interventions within the same timeframe, it provided limited exposure to Bite Back, which is designed as a 6-week program (around 10 minutes per session), and may not have allowed participants sufficient time to fully engage with its features and content. Additionally, the short engagement period within a longer timeframe may have affected participants’ recall of content for both interventions, potentially influencing their perceptions and the depth of their feedback. To mitigate these limitations and aid recall, a think-aloud component was included, although it is acknowledged that the shortened engagement period may still have impacted the depth of participants’ experiences with the interventions.

This study highlights the importance of involving young people in the co-design of digital mental health interventions to ensure content is age-appropriate, relatable, and engaging. In particular, future designs should consider the varying needs across different age ranges, as even small differences in age can affect how content is perceived and whether it feels relevant. Transparent communication about data use and the purpose of interventions should be clear and accessible while avoiding information overload. Future qualitative research could explore accessible and informative ways of communicating essential information, such as data use or the purpose of tasks, to build trust while maintaining engagement within digital mental health interventions.

This study contributes to the growing body of knowledge by identifying 7 interconnected themes that could shape how young people engage with digital mental health interventions. These findings emphasize that young people value interventions that feel relevant to their age, culture, and stage of life, and that are transparent about their purpose, data use, and content. Even slight differences in age appeared to influence how appropriate the interventions felt to participants, highlighting the importance of involving young people in the design process to ensure interventions reflect their needs and preferences and clearly convey information that could support their engagement.