This paper reviews the current evidence and synthesizes fifteen years of real-world development, testing, and implementation of digital mental health interventions (DMHIs) for young people. Drawing on the work of Orygen Digital, we outline the evolution of interventions including the Moderated Online Social Therapy (MOST) platform, the Mello app, and a suite of virtual reality-based therapies; all developed to meet the complex clinical, developmental, and service needs of youth aged 12 to 25.We identify ten key challenges and opportunities encountered in designing, developing and implementing these DMHIs: (1) meaningful co-design; (2) sustained user engagement; (3) personalization and transdiagnostic targeting; (4) optimizing intensities of human support; (5) leveraging peer support and social networking; (6) embedding DMHIs in clinical services; (7) blending digital and face-to-face care; (8) building data infrastructure and learning health systems; (9) developing sustainable and scalable business models; and (10) preparing DMHIs for large language models. Each theme reflects both achievements and persistent challenges, and is illustrated through a synthesis of the current evidence and real-world insights from our clinical trials and national-scale service implementations.Our approach is grounded in various frameworks including clinical staging, self-determination theory, supportive accountability, and minimally disruptive medicine. Emerging innovations such as just-in-time adaptive interventions, extended reality (XR) therapies, stratified treatment models, and large language models offer promising future pathways for greater personalization, engagement, effectiveness, and scalability.Our findings highlight the potential value of context-sensitive, co-designed, and system-integrated DMHIs, while also emphasising enduring limitations such as variable engagement, implementation barriers, and population-specific adaptation. Moving beyond controlled efficacy trials toward agile, real-world learning health systems will be essential to realising the full potential of DMHIs in transforming youth mental health care.

BackgroundThird-wave psychological treatments such as acceptance and commitment therapy can be effective for improving depression and anxiety in youth. However, third-wave therapeutic techniques such as cognitive defusion can be abstract, challenging to learn, and difficult to apply in real-world settings. Translating these techniques into virtual reality (VR) may provide interactive, enjoyable, and concrete learning opportunities, potentially enhancing engagement and effectiveness. This study evaluated a novel VR application that translates the technique of cognitive defusion into a brief, gamified VR experience. ObjectiveThe objectives of this study were to evaluate the feasibility, acceptability, usability, and safety of the VR cognitive defusion application; examine whether it could improve negative thinking and mood states; and understand how it compared to a non-VR cognitive defusion exercise. MethodsIn a mixed methods experimental study, 20 young people completed both a VR and audio cognitive defusion exercise in a randomized order within a single session. Quantitative state-based measures were taken before and after each exercise, and a qualitative interview at the end focused on how the two experiences compared. ResultsIt was feasible to recruit participants, and all participants completed both exercises and assessments. Both the VR and audio exercises were acceptable to participants, with qualitative themes highlighting a preference for VR due to the novel and engaging format; however, there was a need for better guidance and more personalized environments. No severe adverse events were reported, although one participant experienced distress during the VR exercise. Pretest-posttest effects showed improvements in thought discomfort, cognitive defusion, and state anger for both the VR and audio conditions (P<.05), with the latter showing broader improvements, including thought negativity, rumination, tension, depression, distress, and confusion (P<.05). ConclusionsThe VR cognitive defusion application was feasible, safe, and acceptable for young people, with potential to enhance mental health treatment through an engaging and enjoyable approach to learning third-wave cognitive behavioral therapy techniques. While VR was preferred by participants, further refinements could improve effectiveness. Future research should focus on enhancing the VR application design based on user feedback, incorporating audio guidance, and conducting a larger trial in real-world settings to thoroughly evaluate the effectiveness and implementation of the VR application.

With origins in video gaming, 3D virtual worlds (VWs) are digital environments where people engage and interact synchronously using digital characters called avatars. VWs may have future potential for delivering youth mental health (YMH) services. Despite progress in developing VW-based YMH interventions, limited consultation with young people may be contributing to mixed uptake and engagement. This study aimed to understand how young people with experiences accessing YMH services view the potential (i.e., hypothetical) use of VWs for YMH service delivery to understand qualitative factors influencing uptake. Eleven 18–25-year-old consumers (M = 22.91 years; five women, five men, and one non-binary person) took part in one-on-one, semi-structured interviews via videoconferencing. Interviews explored anticipated ease of use, helpfulness, and perceived intention to use VW-based YMH interventions if they were made available. Interviews were analysed using reflexive thematic analysis. Four themes were produced: (1) VWs as unique therapeutic spaces; (2) creative engagement for therapy; (3) VW communication promoting both connection and distance; (4) flexible access. All participants expressed a level of openness towards the potential use of VWs for YMH interventions. Features such as creative world-building and avatar customisation, increased anonymity, and remote accessibility were seen as ways to improve access to convenient, personalised, and engaging mental healthcare. Concerns included technology misuse, privacy risks, and reduced physical and emotional presence. Future research and service development should test real-world outcomes to ensure clinical benefit and employ codesign approaches that leverage servicer-users’ expectations to ensure accessible and acceptable delivery.

Online virtual worlds are platforms that allow users, represented as avatars, to meet and interact with other users in real time within 3D virtual environments. These platforms have potential utility as vehicles to deliver/receive clinical services, especially as a preference to video-conferencing-based telehealth. However, commercial virtual worlds (e.g.,“Second Life”) are often deemed unsuitable due to privacy and safety concerns. The aim of this study was therefore to co-develop and test a bespoke virtual world platform to deliver routine youth mental health services. We undertook a participatory-design process to develop the platform (Orygen Virtual Worlds) involving 10 young people with lived experience of mental health difficulties, researchers, software designers and mental health clinicians. We then tested two types of clinic-led interventions delivered through the virtual world (a structured therapy group and an individual therapy) in a public youth mental health service setting in Australia. Participants were patients receiving treatment in the service. The main outcomes were acceptability and feasibility; we also measured symptom change, usability, presence and therapeutic alliance. We conducted qualitative interviews post-intervention with the participants and analysed these interviews using thematic analysis. 15 young people were recruited to the structured group (27% consented from referred) and 8 were recruited to the individual therapy (36% consented from referred). Drop out was higher in the individual therapy than the structured group therapy (38% versus 80%). Acceptability ratings were high for both therapy approaches and there were no significant safety events attributed to using the platform. There were no significant pre-post differences in the symptom outcome measures in either the structured group intervention or individual therapy. The platform was perceived as being comfortable and safe, enjoyable, fun and interactive, and was not confusing to navigate or difficult to use. The qualitative themes included the platform being fun and engaging, making treatment more accessible, providing a safe and inclusive place, fostering connections, positively impacting wellbeing and providing a catalyst for real life functional change. Young people perceived decreased barriers, increased comfort with help-seeking and reduced social stress facilitated by the avatar, communication options (emoji, text, voice) and accessibility from home. Our findings indicate that online virtual world platforms, such as the one we have designed, hold considerable promise for providing interventions for young people in clinical services. Virtual worlds can provide fun and engaging experiences of therapeutic interventions for young people with mental health difficulties which are safe and inclusive, especially for harder to reach groups.

BACKGROUND:Current treatments for schizophrenia and other psychotic disorders have limited efficacy, with high rates of nonresponse to "gold standard" treatments. New approaches are therefore urgently required. OBJECTIVE:The aims of this pilot study are to investigate the feasibility, acceptability, safety, and usability of Hybrid treatment (primary aim); and to explore Hybrid's treatment efficacy and engagement of treatment targets (secondary aim). The primary aim will be assessed via face-to-face user experience surveys on a (self-assessed) 5-point Likert scale (and qualitative open-ended questions) examining: (1) acceptability, (2) helpfulness, (3) engagement, and (4) perceived safety. We will also examine consent and completion rates, and the number of sessions attended. Our threshold for moving on to efficacy trials will be at least 70% of our participants to rate 3 and above (which corresponds to agree or strongly agree) that the intervention package was acceptable, feasible, and safe. The secondary aims will be assessed by observing whether individuals achieve self-directed modulation of high-β neurophysiological activity (neural target) and progression upwards through the VR-based exposure hierarchy (psychological target), and by assessing symptom change scores. This study developed a new treatment approach for auditory verbal hallucinations, a major symptom of psychotic disorders, that integrates advances in psychological therapy (cognitive behavioral therapy for psychosis), technology (virtual reality, VR), and neuroscience (electroencephalography-based neurofeedback). METHODS:Hybrid takes a "symptom capture" approach using individually tailored VR-based exposure exercises. Participants (N=10) will receive the intervention package weekly over 12 face-to-face sessions. Here, participants will be progressively exposed to symptom triggers and develop methods of downregulating neural activity associated with these symptoms (neurofeedback component) while concurrently receiving clinician-delivered cognitive behavioral therapy for psychosis. RESULTS:As of February 2025, Hybrid has commenced (unblinded) recruitment activities from Orygen clinical services in Northwestern Melbourne, Australia. A total of 75 individuals have been approached and 64 individuals have been prescreened (41 individuals were deemed eligible, 15 individuals were ineligible, and 8 individuals declined or did not respond to contact attempts) and 5 individuals have been included in the study. Of the 5 individuals who have commenced the Hybrid treatment, 4 are actively engaged in the program and 1 individual has withdrawn. We expect recruitment to conclude in July 2025 and for the results to be published in 2026. CONCLUSIONS:The Hybrid study is piloting a novel approach that has the potential to address the shortcomings of current treatments for psychotic symptoms. If there is favorable evidence for the acceptability, feasibility, safety and usability of Hybrid, the study team will move on to efficacy trials. TRIAL REGISTRATION:Australian New Zealand Clinical Trials Registry ACTRN12624000357550; https://tinyurl.com/24ey8hpy. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID):PRR1-10.2196/63405.

Delusions are one of the core symptoms of schizophrenia spectrum disorders (SSD), associated with distress and impaired functioning. Traditional Cognitive Behavioral Therapy (CBT) approaches are less effective for delusions, require significant resources, and specialized staff training. Symptom-specific therapy approaches, which target factors involved in the development and maintenance of psychotic symptoms, provide a valid alternative. Recent research demonstrates the efficacy of coping strategies as an intervention element, however, so far, only in the context of auditory hallucinations. Digital technologies, such as ecological momentary assessment (EMA) and ecological momentary intervention (EMI), are gaining attention in mental health, providing enhanced assessment and intervention opportunities. The present single-arm trial aimed to investigate the feasibility, acceptability, and preliminary outcomes of a smartphone-based blended EMA/I psychological therapy approach focusing on improving coping strategies for delusions in SSD. In total, N = 10 participants received four face-toface therapy sessions alongside German university-level treatment-as-usual over an intervention period of four to six weeks. Feasibility was assessed by completion rates of the EMA/I questionnaires, use of the application between sessions and recruitment rates. Acceptability was assessed by a satisfaction questionnaire, open feedback, and analysis of adverse effects. Clinical outcomes included self-rated and rater-based intensity and distress of delusions and comorbid symptoms at pre- and post-intervention. Findings supported the feasibility and acceptability of the DICE (DICE- Delusion Ideation in the Context of Everyday life intervention) intervention, with high retention (10/13 participants, 77 %) and completion rates for the EMA- (59 %) and EMI-questionnaires (72 %), as well as a high protocol adherence (90-97 %), exceeding all predefined benchmarks. Open feedback indicated good satisfaction, with all participants using the application between sessions, reflecting a high engagement level. Clinical outcomes displayed relevant changes in ameliorating the intensity of delusions when being measured by the Psychotic Symptom Rating Scales as well as by the Green Paranoid Thought Scale, and self-rated improvements in distress and depressive symptoms. Changes in the intensity and distress of delusions might be explained by improved coping behaviour. Further research with control conditions is needed to validate findings and analyze the efficacy as well as mechanisms of actions of the intervention in a fully powered trial.

The expanding domain of digital mental health is transitioning beyond traditional telehealth to incorporate smartphone apps, virtual reality, and generative artificial intelligence, including large language models. While industry setbacks and methodological critiques have highlighted gaps in evidence and challenges in scaling these technologies, emerging solutions rooted in co-design, rigorous evaluation, and implementation science offer promising pathways forward. This paper underscores the dual necessity of advancing the scientific foundations of digital mental health and increasing its real-world applicability through five themes. First, we discuss recent technological advances in digital phenotyping, virtual reality, and generative artificial intelligence. Progress in this latter area, specifically designed to create new outputs such as conversations and images, holds unique potential for the mental health field. Given the spread of smartphone apps, we then evaluate the evidence supporting their utility across various mental health contexts, including well-being, depression, anxiety, schizophrenia, eating disorders, and substance use disorders. This broad view of the field highlights the need for a new generation of more rigorous, placebo-controlled, and real-world studies. We subsequently explore engagement challenges that hamper all digital mental health tools, and propose solutions, including human support, digital navigators, just-in-time adaptive interventions, and personalized approaches. We then analyze implementation issues, emphasizing clinician engagement, service integration, and scalable delivery models. We finally consider the need to ensure that innovations work for all people and thus can bridge digital health disparities, reviewing the evidence on tailoring digital tools for historically marginalized populations and low- and middle-income countries. Regarding digital mental health innovations as tools to augment and extend care, we conclude that smartphone apps, virtual reality, and large language models can positively impact mental health care if deployed correctly.

BackgroundFear of relapse into psychosis is an independent risk factor for future relapse events, indicating its importance as a novel intervention target.MethodsTwenty-five participants responded to daily ecological momentary assessment prompts assessing common early warning signs of relapse and self-reported positive experiences like feeling supported by others. We conducted multilevel vector auto-regression using common symptoms assessed in early warning signs monitoring relapse prevention while controlling for positive self-reported experiences like feeling supported by others to estimate three networks (to explore concurrent, temporal and overall relationships).ResultsReporting fear of relapse was positively associated (within the same cross-sectional time window) with hearing voices, alongside anxiety, negative affect and sleep change. Fear of relapse appeared to predict anxiety, negative affect and greater fear of relapse on the next consecutive day. However, none of the typical early warning signs predicted fear of relapse within the temporal window, and the observed relationships were small.DiscussionEarly warning signs appeared to be poor predictors of experiencing fear of relapse in this study. Fear of relapse predicts later anxiety and negative affect and may be a valuable intervention target within the daily life of people diagnosed with schizophrenia.

Background Digital health interventions (DHIs) have significant potential to upscale treatment access to people experiencing psychosis but raise questions around patient safety. Adverse event (AE) monitoring is used to identify, record, and manage safety issues in clinical trials, but little is known about the specific content and context contained within extant AE reports. This study aimed to assess current AE reporting in DHIs.Study Design A systematic literature search was conducted by the iCharts network (representing academic, clinical, and experts by experience) to identify trials of DHIs in psychosis. Authors were invited to share AE reports recorded in their trials. A content analysis was conducted on the shared reports.Study Results We identified 593 AE reports from 18 DHI evaluations, yielding 19 codes. Only 29 AEs (4.9% of total) were preidentified by those who shared AEs as being related to the intervention or trial procedures. While overall results support the safety of DHIs, DHIs were linked to mood problems and psychosis exacerbation in a few cases. Additionally, 27% of studies did not report information on relatedness for all or at least some AEs; 9.6% of AE reports were coded as unclear because it could not be determined what had happened to participants.Conclusions The results support the safety of DHIs, but AEs must be routinely monitored and evaluated according to best practice. Individual-level analyses of AEs have merit to understand safety in this emerging field. Recommendations for best practice reporting in future studies are provided.

This systematic review and meta-analysis examined the efficacy of digital mental health apps and the impact of persuasive design principles on engagement and clinical outcomes. Of 119 eligible randomised controlled trials, 92 studies (n=16,728) were included in the analysis. Results demonstrated that mental health apps significantly improved clinical outcomes compared to control groups (g = 0.43). Apps used between 1 and 12 persuasive design principles (mode = 5). Notably, only 76% of studies reported engagement data. Twenty-five engagement metrics were identified across studies and grouped into 10 categories. Meta-regression and correlation analyses found no significant association between persuasive design principles and app efficacy or engagement. Future research should prioritise standardising and documenting engagement metrics and persuasive design principles; differentiating between engagement with mental health apps and real-world behavioural change and exploring the integration of persuasive design with behaviour change models to more accurately assess their influence on engagement and outcomes.

Background:Artificial intelligence (AI) has been increasingly recognized as a potential solution to address mental health service challenges by automating tasks and providing new forms of support. Objective:This study is the first in a series which aims to estimate the current rates of AI technology use as well as perceived benefits, harms, and risks experienced by community members (CMs) and mental health professionals (MHPs). Methods:This study involved 2 web-based surveys conducted in Australia. The surveys collected data on demographics, technology comfort, attitudes toward AI, specific AI use cases, and experiences of benefits and harms from AI use. Descriptive statistics were calculated, and thematic analysis of open-ended responses were conducted. Results:The final sample consisted of 107 CMs and 86 MHPs. General attitudes toward AI varied, with CMs reporting neutral and MHPs reporting more positive attitudes. Regarding AI usage, 28% (30/108) of CMs used AI, primarily for quick support (18/30, 60%) and as a personal therapist (14/30, 47%). Among MHPs, 43% (37/86) used AI; mostly for research (24/37, 65%) and report writing (20/37, 54%). While the majority found AI to be generally beneficial (23/30, 77% of CMs and 34/37, 92% of MHPs), specific harms and concerns were experienced by 47% (14/30) of CMs and 51% (19/37) of MHPs. There was an equal mix of positive and negative sentiment toward the future of AI in mental health care in open feedback. Conclusions:Commercial AI tools are increasingly being used by CMs and MHPs. Respondents believe AI will offer future advantages for mental health care in terms of accessibility, cost reduction, personalization, and work efficiency. However, they were equally concerned about reducing human connection, ethics, privacy and regulation, medical errors, potential for misuse, and data security. Despite the immense potential, integration into mental health systems must be approached with caution, addressing legal and ethical concerns while developing safeguards to mitigate potential harms. Future surveys are planned to track use and acceptability of AI and associated issues over time.

Virtual reality (VR) has emerged as a promising tool in the field of mental health. Central to this technology are immersive environments, which enable exposure to highly controlled virtual experiences that feel real. In this Review, we elaborate on the active elements of immersive experiences and how VR-based treatments work. We provide an overview of developments in the use of VR to treat mental health conditions (anxiety, psychotic symptoms, post-traumatic stress, eating disorders, depression and stress management) with a focus on the core mechanisms that drive effective interventions. Artificial intelligence, biofeedback and gamification are emerging areas of development, and we discuss how they might enhance the accessibility, engagement and effectiveness of psychological treatments. Conducting rigorous studies with user-centred designs in diverse populations is a key research priority. As the use of VR in mental health continues to evolve, addressing ethical and implementation considerations is critical for ensuring ongoing treatment improvements. Virtual reality (VR) enables highly controlled exposure to environments that feel real, which can substantially improve mental health treatments. In this Review, Bell and colleagues describe current VR-based treatments and discuss technological and psychological tools that might promote enhanced immersive experiences.

Background The increasing rates of mental health challenges among young people highlight an urgent need for accessible and effective treatment. However, current mental health systems face unprecedented demand, leaving most young people globally with unmet mental health needs. Smartphones present a promising solution to this issue by offering in-the-moment support through innovative just-in-time adaptive interventions, which provide support based on real-time data. Objective This study explores young people’s experiences with Mello, a just-in-time adaptive intervention that focuses on the transdiagnostic mechanism of repetitive negative thinking (RNT), a significant factor contributing to youth depression and anxiety. Methods Semistructured qualitative interviews were conducted with 15 participants aged 16 to 25 years, all of whom had previously participated in a pilot randomized controlled trial of Mello. Of the 15 participants, 9 (60%) identified as women, 4 (27%) as men (including 1 transgender man), and 2 (13%) as nonbinary. Interviews focused on participants’ experiences with the Mello app, factors influencing engagement, perceived benefits and limitations, and suggestions for future improvements. Thematic analysis was used to analyze the data. Results The analysis identified three superordinate themes: Mello as a tool for intentional reflection; doing therapy your own way; and barriers to engagement during low mood, anxiety, and RNT. Theme 1 explored young people’s experiences of how the app facilitated active management of negative thoughts and supported the development of reflective habits, contrasting with their typical strategies of avoidance or resistance. Theme 2 highlighted the value of the app’s self-guided nature, with a particular focus on its flexibility and accessibility, particularly when compared to traditional face-to-face therapy. Finally, theme 3 addressed barriers to engagement, particularly during emotionally difficult times, with participants reporting feeling “stuck” in their negative thoughts. To mitigate these challenges, participants suggested incorporating gamification elements, such as progress-tracking visuals, to enhance motivation and increase engagement with the app. Conclusions Our findings underscored the value of Mello in promoting intentional engagement and reflection with RNT, consistent with prior research that emphasizes the effectiveness of tailored interventions. Although some users valued the self-guided nature of the application, others encountered difficulties with motivation. Future research should explore strategies to enhance engagement for young people with low mood and motivation, such as co-design methodologies, advanced personalization features, and gamification techniques.

AbstractBackgroundDepression and anxiety are prevalent in youth populations and typically emerge during adolescence. Repetitive negative thinking (RNT) is a putative transdiagnostic mechanism with consistent associations with depression and anxiety. Targeting transdiagnostic processes like RNT for youth depression and anxiety may offer more targeted, personalised and effective treatment.MethodsA meta-analysis was conducted to examine the effect of psychological treatments on RNT, depression and anxiety symptoms in young people with depression or anxiety, and a meta-regression to examine relationships between outcomes.ResultsTwenty-eight randomised controlled trials examining 17 different psychological interventions were included. Effect sizes were small to moderate across all outcomes (Hedge's g depression = −0.47, CI −0.77 to −0.17; anxiety = −0.42, CI −0.65 to −0.20; RNT = −0.45, CI −0.67 to −0.23). RNT-focused and non-RNT focused approaches had comparable effects; however, those focusing on modifying the process of RNT had significantly larger effects on RNT than those focusing on modifying negative thought content. Meta-regression revealed a significant relationship between RNT and depression outcomes only across all intervention types and with both depression and anxiety for RNT focused interventions only.ConclusionConsistent with findings in adults, this review provides evidence that reducing RNT with psychological treatment is associated with improvements in depression and anxiety in youth. Targeting RNT specifically may not lead to better outcomes compared to general approaches; however, focusing on modifying the process of RNT may be more effective than targeting content. Further research is needed to determine causal pathways.

Objective Integrating digital technologies with clinical practice promises to improve access and enhance care in the context of high service demand and constrained capacity. Method We outline the emerging research in the integration of digital tools in clinical care, known as blended care, and provide case examples of mental health technology platforms currently in use, summarise findings regarding novel technologies such as virtual reality, and outline real-world implementation challenges and potential solutions. Results Recent evidence shows that blended care approaches are clinically effective and improve service efficiency. Youth-specific technologies such as moderated online social therapy (MOST) are achieving a range of positive clinical and functional outcomes, while emerging technologies like virtual reality have strong evidence in anxiety disorder, and accumulating evidence in psychotic conditions. Implementation science frameworks show promise in helping overcome the common challenges faced in real-world adoption and ongoing use. Conclusion The integrated, blended use of digital mental health technologies with face-to-face clinical care has the potential to improve care quality for young people while helping overcome the growing challenges faced by youth mental health service providers.

The COVID-19 pandemic has presented profound disruptions to young people at a critical period of psychosocial development. The current study aimed to explore the perceived negative and positive impacts of the COVID-19 pandemic on young people's mental health and wellbeing across a spectrum of clinical needs. A cross-sectional online survey including both quantitative and qualitative responses captured positive and negative impacts of COVID-19 across 593 young people with and without mental health care needs. Findings revealed high levels of clinical depression (48%), anxiety (51%), and loneliness in both samples. Approximately 75% of young people in primary mental health care services, and over 80% in the general population, reported a negative impact on work, non-work activities and mental health and wellbeing. Open-ended responses reflected positive impacts in the domains of greater capacity for self-care and reflection due to the decreased pressures of daily life. Negative impacts reflected worsening mental health, disruptions to key developmental milestones regarding relationships with self and others, and limited capacity for self-care. Together, these data highlight the critical need for early intervention support for the psychosocial impacts experienced by young people due to the pandemic, particularly among those with existing mental health care needs.

Background Ecological momentary assessment (EMA) involves completing multiple surveys over time in daily life, capturing in-the-moment experiences in real-world contexts. EMA use in psychosis studies has surged over several decades. To critically examine EMA use in psychosis research and assist future researchers in designing new EMA studies, this systematic review aimed to summarize the methodological approaches used for positive symptoms in psychosis populations and evaluate feasibility with a focus on completion rates. Methods A systematic review of PubMed, PsycINFO, MEDLINE, Web of Science, EBSCOhost, and Embase databases using search terms related to EMA and psychosis was conducted. Excluding duplicate samples, a meta-analysis was conducted of EMA survey completion rates and meta-regression to examine predictors of completion. Results Sixty-eight studies were included in the review. Characteristics and reporting of EMA methodologies were variable across studies. The meta-mean EMA survey completion computed from the 39 unique studies that reported a mean completion rate was 67.15% (95% CI = 62.3, 71.9), with an average of 86.25% of the sample meeting a one-third EMA completion criterion. No significant predictors of completion were found in the meta-regression. A variety of EMA items were used to measure psychotic experiences, of which few were validated. Conclusions EMA methods have been widely applied in psychosis studies using a range of protocols. Completion rates are high, providing clear evidence of feasibility in psychosis populations. Recommendations for reporting in future studies are provided.

Background Repetitive negative thinking (RNT) is a key transdiagnostic mechanism underpinning depression and anxiety. Using “just-in-time adaptive interventions” via smartphones may disrupt RNT in real time, providing targeted and personalized intervention. Objective This pilot randomized controlled trial evaluates the feasibility, acceptability, and preliminary clinical outcomes and mechanisms of Mello—a fully automated, personalized, transdiagnostic, and mechanistic smartphone intervention targeting RNT in young people with depression and anxiety. Methods Participants with heightened depression, anxiety, and RNT were recruited via social media and randomized to receive Mello or a nonactive control over a 6-week intervention period. Assessments were completed via Zoom sessions at baseline and at 3 and 6 weeks after baseline. Results The findings supported feasibility and acceptability, with high rates of recruitment (N=55), uptake (55/64, 86% of eligible participants), and retention (52/55, 95% at 6 weeks). Engagement was high, with 90% (26/29) and 59% (17/29) of the participants in the Mello condition still using the app during the third and sixth weeks, respectively. Greater reductions in depression (Cohen d=0.50), anxiety (Cohen d=0.61), and RNT (Cohen d=0.87) were observed for Mello users versus controls. Mediation analyses suggested that changes in depression and anxiety were accounted for by changes in RNT. Conclusions The results indicate that mechanistic, targeted, and real-time technology-based solutions may provide scalable and effective interventions that advance the treatment of youth mental ill health. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN12621001701819; http://tinyurl.com/4d3jfj9f