A holistic lifestyle mobile health intervention for the prevention of type 2 diabetes and common mental disorders in Asian women with a history of gestational diabetes: a randomised control trial with 3-year follow-up protocol.

BACKGROUND: Women with a history of gestational diabetes mellitus (GDM) are 12-fold more likely to develop type 2 diabetes (T2D) 4-6 years after delivery than women without GDM. Similarly, GDM is associated with the development of common mental disorders (CMDs) (e.g. anxiety and depression). Evidence shows that holistic lifestyle interventions focusing on physical activity (PA), dietary intake, sleep, and mental well-being strategies can prevent T2D and CMDs. This study aims to assess the effectiveness of a holistic lifestyle mobile health intervention (mHealth) with post-GDM women in preventing T2D and CMDs in a community setting in Singapore. METHODS: The study consists of a 1-year randomised controlled trial (RCT) with a 3-year follow-up period. Post-GDM women with no current diabetes diagnosis and not planning to become pregnant will be eligible for the study. In addition, participants will complete mental well-being questionnaires (e.g. depression, anxiety, sleep) and their child's socio-emotional and cognitive development. The participants will be randomised to either Group 1 (Intervention) or Group 2 (comparison). The intervention group will receive the "LVL UP App", a smartphone-based, conversational agent-delivered holistic lifestyle intervention focused on three pillars: Move More (PA), Eat Well (Diet), and Stress Less (mental wellbeing). The intervention consists of health literacy and psychoeducational coaching sessions, daily "Life Hacks" (healthy activity suggestions), slow-paced breathing exercises, a step tracker (including brisk steps), a low-burden food diary, and a journaling tool. Women from both groups will be provided with an Oura ring for tracking physical activity, sleep, and heart rate variability (a proxy for stress), and the "HAPPY App", a mHealth app which provides health promotion information about PA, diet, sleep, and mental wellbeing, as well as display body mass index, blood pressure, and results from the oral glucose tolerance tests. Short-term aggregate effects will be assessed at 26/27 weeks (midpoint) and a 1-year visit, followed by a 2, 3, and 4-year follow-up period. DISCUSSION: High rates of progression of T2D and CMDs in women with post-GDM suggest an urgent need to promote a healthy lifestyle, including diet, PA, sleep, and mental well-being. Preventive interventions through a holistic, healthy lifestyle may be the solution, considering the inextricable relationship between physical and psychological health. We expect that holistic lifestyle mHealth may effectively support behavioural changes among women with a history of GDM to prevent T2D and CMDs. TRIAL STATUS: The protocol study was approved by the National Healthcare Group in Singapore, Domain Specific Review Board (DSRB) [2023/00178]; June 2023. Recruitment began on October 18, 2023. TRIAL REGISTRATION: ClinicalTrials.gov NCT05949957. The first submission date is June 08, 2023.

[Prevention of psychiatric illness]. / La prévention des maladies psychiatriques.

Prevention and early intervention in the field of mental health are recognized as key elements in minimizing the impact of any potentially serious mental health condition. However, early intervention in the field of young people's health is an objective that is underdeveloped. There are several possible avenues of prevention: selective preventive interventions for individuals whose risk of developing a mental disorder is significantly higher than the rest of the population, interventions for individuals who are no longer asymptomatic, secondary prevention strategies aimed at mitigating the onset of negative prognostic factors, and tertiary prevention strategies aimed at remedying resistance to treatment and psychosocial dysfunction. Epigenetics will undoubtedly be a promising area for the prevention of mental disorders in the future. Epigenetic processes, which can be modified by preventive measures such as physical activity, could lead to resilience to mental disorders. Finally, lifestyle factors (physical exercise, diet, smoking, lack of sleep) could also play a role in the emergence or prevention of mental illness.

La prévention et l'intervention précoce dans le domaine de la santé mentale sont reconnues comme des éléments-clés pour minimiser l'impact de tout état de santé mental potentiellement grave. Cependant, l'intervention précoce dans le domaine de la santé des jeunes est un objectif qui n'est qu'insuffisamment développé. Plusieurs axes de prévention peuvent se rencontrer : les interventions de prévention sélective chez des individus dont le risque de développer un trouble mental est significativement plus élevé que le reste de la population, les interventions indiquées chez des individus qui ne sont plus asymptomatiques, les stratégies de prévention secondaire visant à atténuer l'apparition de facteurs pronostiques négatifs, les stratégies de prévention tertiaire visant à remédier à la résistance au traitement et au dysfonctionnement psychosocial. L'épigénétique constituera, sans aucun doute, à l'avenir, un domaine prometteur pour la prévention des troubles mentaux. Les processus épigénétiques, modifiables par des mesures préventives comme l'activité physique, pourraient conduire à la résilience des troubles mentaux. Enfin, des facteurs liés au mode de vie (exercice physique, alimentation, tabac, manque de sommeil) pourraient également jouer un rôle dans l'émergence ou la prévention des maladies mentales.

The Role of School-based Interventions and Communities for Mental Health Prevention, Tiered Levels of Care, and Access to Care.

This article highlights the key role of schools in addressing rising mental health disorders among youth. It champions collaboration between health and educational sectors, emphasizing child and adolescent psychiatrists' significant contribution to school-based mental health literacy and interventions. This article encourages for child and adolescent psychiatrists' involvement in policy advocacy for accessible and inclusive mental health care, championing sustainable mental health services through advocating for funding, training, and policy support.

Sibling-Support for Adolescent Girls (SSAGE): A study protocol for a pilot randomized-controlled trial of a whole-family, gender transformative approach to preventing mental illness among forcibly displaced adolescent girls.

BACKGROUND: Forcibly displaced adolescents face increased risks for mental illness and distress, with adolescent girls disproportionately affected in part due to heightened gender inequity. Although the family unit has the potential to promote healthy development in adolescents, few family interventions have employed a gender transformative approach or included male siblings to maximize benefits for adolescent girls. METHODS: This study will assess a whole-family and gender transformative intervention-Sibling Support for Adolescent Girls in Emergencies (SSAGE)-to prevent mental health disorders among adolescent girls in Colombia who were recently and forcibly displaced from Venezuela. The study will employ a hybrid type 1 effectiveness-implementation pilot randomized control trial (RCT) to test the program's effectiveness to explore determinants of implementation to establish the feasibility, acceptability, and fidelity of SSAGE. To address these aims, we will enroll 180 recently arrived, forcibly displaced adolescent girls in an RCT and examine the program's effectiveness in the prevention of mental illness (through reduction in anxiety, depression, interpersonal sensitivity, and somatization symptoms) one-month post-intervention. We will use contextually adapted to collect data on the hypothesized mechanistic pathways, including family attachment, gender-equitable family functioning, self-esteem, and coping strategies. The implementation evaluation will employ mixed methods to assess the program's feasibility, acceptability, fidelity, and barriers and facilitators to successful implementation. DISCUSSION: Findings can support humanitarian program implementation, as well as inform policy to support adolescent girls' mental health and to prevent the myriad disorders that can arise as a result of exposure to displacement, conflict, and inequitable gender norms.

Effectiveness of combining prevention psychological interventions with interventions that address the social determinants of mental health in low and middle-income countries: protocol of a systematic review and meta-analysis.

INTRODUCTION: Common mental health conditions (CMHCs), including depression, anxiety and post-traumatic stress disorder (PTSD), are highly prevalent in low and middle-income countries (LMICs). Preventive strategies combining psychological interventions with interventions addressing the social determinants of mental health may represent a key strategy for effectively preventing CMHCs. However, no systematic reviews have evaluated the effectiveness of these combined intervention strategies for preventing CMHCs. METHODS AND ANALYSIS: This systematic review will include randomised controlled trials (RCTs) focused on the effectiveness of interventions that combine preventive psychological interventions with interventions that address the social determinants of mental health in LMICs. Primary outcome is the frequency of depression, anxiety or PTSD at postintervention as determined by a formal diagnostic tool or any other standardised criteria. We will search Epistemonikos, Cochrane Controlled Trials Register (CENTRAL), MEDLINE, Embase, PsycINFO, CINAHL, Global Index Medicus, ClinicalTrials.gov (Ctgov), International Clinical Trials Registry Platform (ICTRP). Two reviewers will independently extract the data and evaluate the risk of bias of included studies using the Cochrane risk of bias tool 2. Random-effects meta-analyses will be performed, and certainty of evidence will be rated using the Grading of Recommendations Assessment, Development and Evaluation approach. ETHICS AND DISSEMINATION: This study uses data from published studies; therefore, ethical review is not required. Findings will be presented in a published manuscript. TRIAL REGISTRATION NUMBER: CRD42023451072.

Developing a hope-focused intervention to prevent mental health problems and improve social outcomes for young women who are not in education, employment, or training (NEET): A qualitative co-design study in deprived coastal communities in South-East England.

Young women who are not in education, employment, or training (NEET) experience poorer health and social outcomes compared to non-NEET young women and to NEET young men, especially in deprived areas with intersecting inequalities. The evidence on effective public health approaches is scarce. Interventions that target hope, which NEET young women notably lack, offer a promising theory-driven and intuitive means to prevent mental health problems and improve social outcomes. Hope can be defined as a goal-focused mindset comprising self-agency (motivation and self-belief) and pathways (identifying routes to achieving goals). Hope is implicated in a variety of evidence-based psychosocial interventions for young people, but is not directly targeted by existing prevention programmes for NEET populations. The current study used a phased qualitative research design and participatory methods to model a hope-focused intervention for NEET young women. Phase 1 investigated population needs and intervention parameters through semi-structured interviews with 28 key informants living or working in disadvantaged coastal communities in South-East England. The sample comprised eight NEET young women, four family members, and 16 practitioners from relevant support organisations. Phase 2 refined intervention parameters and outcomes through co-design sessions with four NEET young women, followed by a theory of change workshop with 10 practitioners. The resulting intervention model is articulated as a mentor-supported, in-person psychosocial intervention that builds hope by enhancing positive sense of self and time spent in meaningful activities, before explicitly teaching the skills needed to identify, set, and pursue personally meaningful goals.

An urgent call to address work-related psychosocial hazards and improve worker well-being.

Work-related psychosocial hazards are on the verge of surpassing many other occupational hazards in their contribution to ill-health, injury, disability, direct and indirect costs, and impact on business and national productivity. The risks associated with exposure to psychosocial hazards at work are compounded by the increasing background prevalence of mental health disorders in the working-age population. The extensive and cumulative impacts of these exposures represent an alarming public health problem that merits immediate, increased attention. In this paper, we review the linkage between work-related psychosocial hazards and adverse effects, their economic burden, and interventions to prevent and control these hazards. We identify six crucial societal actions: (1) increase awareness of this critical issue through a comprehensive public campaign; (2) increase etiologic, intervention, and implementation research; (3) initiate or augment surveillance efforts; (4) increase translation of research findings into guidance for employers and workers; (5) increase the number and diversity of professionals skilled in preventing and addressing psychosocial hazards; and (6) develop a national regulatory or consensus standard to prevent and control work-related psychosocial hazards.

[The German Center for Mental Health : Innovative translational research to promote prevention, targeted intervention and resilience]. / Das Deutsche Zentrum für Psychische Gesundheit : Innovative Translationsforschung zur Förderung von Prävention, zielgerichteter Intervention und Resilienz.

BACKGROUND: Due to the high disease burden, the early onset and often long-term trajectories mental disorders are among the most widespread diseases with growing significance. The German Center for Mental Health (DZPG) was established to enhance research conditions and expedite the translation of clinically relevant findings into practice. OBJECTIVE: The aim of the DZPG is to optimize mental healthcare in Germany, influence modifiable social causes and to develop best practice models of care for vulnerable groups. It seeks to promote mental health and resilience, combat the stigmatization associated with mental disorders, and contribute to the enhancement of treatment across all age groups. MATERIAL AND METHODS: The DZPG employs a translational research program that accelerates the translation of basic research findings into clinical studies and general practice. University hospitals and outpatient departments, other university disciplines, and extramural research institutions are working together to establish a collaboratively coordinated infrastructure for accelerated translation and innovation. RESEARCH PRIORITIES: The research areas encompass 1) the interaction of somatic and mental risk and resilience factors and disorders across the lifespan, 2) influencing relevant modifiable environmental factors and 3) based on this personalized prevention and intervention. CONCLUSION: The DZPG aims to develop innovative preventive and therapeutic tools that enable an improvement in care for individuals with mental disorders. It involves a comprehensive integration of experts with experience at all levels of decision-making and employs trilogue and participatory approaches in all research projects.

A 'Vocal Locals' social network campaign is associated with increased frequency of conversations about mental health and improved engagement in wellbeing-promoting activities in an Australian farming community.

BACKGROUND: Farmers face numerous barriers to accessing professional mental health services and instead report a preference for informal support systems, such as lay or peer networks. Farmers also experience barriers to investing time in maintaining or improving their wellbeing, stemming from sociocultural norms and attitudes that are widespread in agricultural communities. The Vocal Locals social network campaign is an ifarmwell initiative that aims to promote conversations about wellbeing and challenge attitudes and behaviours that contribute to farmers' poor mental health. METHODS: The Vocal Locals campaign was underpinned by the socio-ecological model which explains human behaviour as stemming from interactions between the individual, their closest social circle, the community, and broader society. The campaign ran in Loxton, South Australia, from June to August 2022. Ten community members (8/10 farmers) became 'Vocal Locals' and were supported to share 'calls-to-action' to encourage people in their social networks to engage in wellbeing-promoting activities. A broader communications campaign reinforced key messages and amplified Vocal Locals' activities in the community. The intrapersonal and community-level impacts of the campaign were evaluated via pre- and post-campaign surveys of Vocal Locals and community members respectively. RESULTS: Vocal Locals reported significantly lower psychological distress (p = .014), and higher positive mental wellbeing (p = .011), levels of general mental health knowledge (p = .022), and confidence helping someone with poor mental health (p = .004) following the intervention. However, changes in stigmatising beliefs about mental illness, confidence recognising poor mental health, and confidence and comfort speaking to others about mental health were non-significant. Community members who were familiar with the campaign reported having significantly more wellbeing-related conversations post-campaign compared to before (p = .015). Respondents also reported being more comfortable speaking to others about mental health or wellbeing (p = .001) and engaging more in activities to maintain or improve their wellbeing (p = .012) following the campaign. CONCLUSIONS: The Vocal Locals social network campaign is an example of how science and community can be brought together to achieve meaningful outcomes. The campaign may serve as a model for others who wish to challenge attitudinal or knowledge-related barriers to help-seeking and improve engagement in wellbeing-promoting activities in difficult-to-reach communities.

Stress First Aid for Health-care Workers: An Indicated Mental Illness Prevention Program for Nursing Education.

Spurred by a global pandemic, the incidence and prevalence of stress-related injury and illness continues to increase amid an overburdened nursing workforce that has remarkably and reliably performed on the frontlines of health care. Indicated mental illness prevention programs such as Stress First Aid for Healthcare Workers create an opportunity to target the acute and chronic expressions of stress experienced by nurses earlier through coordinated peer support with the goals of preserving life, preventing further harm, and promoting recovery. This article will describe how a Stress First Aid program was operationalized at a school of nursing at a private university.

Effectiveness of information technology assisted relapse prevention program on relapse among people who live with severe mental disorders.

BACKGROUND: Severe Mental Disorders (SMDs) cause mental health worldwide challenges because of several relapses and extensive recovery periods of hospitalization, which put a lot of economic and social burden on families and governments. Therefore, interventions are necessary to decrease the relapse of these disorders. AIM: This study was conducted to investigate the effect of Information Technology Assisted Relapse Prevention Program (ITAREP) on relapse among people who live with SMDs. METHOD: This study was a randomized clinical trial with intervention and control groups. ITAREP is a remote intervention based on monitoring the Early Warning Signs (EWS) to decrease the number of potential relapses. Using convenience sampling, people with SMDs admitted to Sina Juneqan Psychiatric Hospital and their caregivers were recruited in this study and randomly allocated to the control and intervention groups. Two checklists of the EWS for the patient and the patient's caregiver were used for monitoring the relapse signs. Data were collected at baseline and 90 days after discharge and were analyzed using t-test and Chi-square statistical tests and linear regression in SPSS software. RESULTS: Fifty-two patients who lived with SMDs participated in this study (26 in the intervention group and 26 in the control group). The two groups were homogeneous regarding age, gender, type of mental disorder, and duration of the disorder. Forty-two males and ten females participated in this research. Most of the participants were diagnosed with schizophrenia. The results showed that the number of relapses in the intervention group was significantly lower than in the control group in the post-test. CONCLUSION: Social workers, as the case managers and a member of the interdisciplinary psychiatric team, can actively perform follow-up measures after discharge using ITAREP, and it can be expected that these interventions will reduce the number of relapses among patients who live with SMDs.

Effectiveness of gamified digital interventions in mental health prevention and health promotion among adults: a scoping review.

BACKGROUND: Though still a young field of research, gamified digital interventions have demonstrated potential in exerting a favourable impact on health and overall well-being. With the increasing use of the internet and digital devices, the integration of game elements presents novel opportunities for preventing mental disorders and enhancing mental health. Hence, this review aims to assess the effectiveness of gamified interventions focusing on preventing mental disorders or promoting mental health among adults. METHODS: Based on a scoping review across four databases (MEDLINE, Embase, PsycInfo and Web of Science), 7,953 studies were initially identified. After removing duplicates and screening titles, abstracts and full texts, 16 studies were identified as suitable for inclusion in a narrative synthesis of findings. We included interventional studies encompassing an intervention and a control group aiming to investigate the effectiveness of the use of gamified digital mental health interventions and the use of gamified digital elements. RESULTS: Overall, positive effects of gamified interventions on mental health-related outcomes were identified. In particular, beneficial consequences for psychological well-being and depressive symptoms were observed in all studies. However, further outcomes, such as resilience, anxiety, stress or satisfaction with life, showed heterogenous findings. Most game elements used were reward, sensation and progress, whilst the quantity of elements was not consistent and, therefore, no substantiated conclusion regarding the (optimal) quantity or composition of game elements can be drawn. Further, the outcomes, measurements and analyses differed greatly between the 16 included studies making comparisons difficult. CONCLUSION: In summary, this review demonstrates the potential of integrating digital game elements on mental health and well-being with still a great gap of research. A taxonomy is needed to adequately address relevant game elements in the field of mental health promotion and prevention of mental disorders. Therefore, future studies should explicitly focus on the mechanisms of effect and apply rigorous study designs.

Guidelines toward more socially just mental health screening in schools.

Mental health screening is a pivotal practice for promoting the social-emotional-behavioral (SEB) health and well-being of youth in schools. However, some aspects of traditional mental health screening practices may inadvertently perpetuate structural racism and unintentionally facilitate oppression and SEB disparities. We address this issue constructively by presenting an intentional approach to guide school psychologists and related professionals in implementing more socially just mental health screening in schools. Our guidelines are grounded within the four phases of the Participatory Culture-Specific Intervention Modeling (PCSIM) framework: system entry, culture-specific model development, culture-specific program development, and program continuation or extension. We propose that conceptualizing mental health screening within PCSIM methodology promotes more socially just practices by (a) displacing the implicit power of professionals, (b) giving transparent representation to local communities, and (c) employing methods that are recursive, culturally relevant, and intended to build capacity for sustained transformative change. Within each PCSIM phase, we recommend culturally responsive practices for professionals that foster equity in screening and SEB outcomes and discuss ways to resist practices that perpetuate oppression and disparities. We aim to convey a method for mental health screening that is not done to students and schools but rather done in partnership with and for the benefit of students and schools. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effectiveness of trauma-focused cognitive behavioral therapy compared to psychosocial counseling in reducing HIV risk behaviors, substance use, and mental health problems among orphans and vulnerable children in Zambia: a community-based randomized controlled trial.

Orphans and vulnerable children (OVC) in sub-Saharan Africa are at high risk for HIV infection and transmission. HIV prevention and treatment efforts with OVC are hindered by mental health and substance use problems. This randomized controlled trial compared a mental health intervention, Trauma Focused Cognitive Behavioral Therapy (TF-CBT), to an enhanced version of an existing HIV Psychosocial Counseling (PC+) program among 610 adolescents who met PEPFAR criteria for OVC and had HIV risk behaviors in Lusaka, Zambia. Outcomes included HIV risk behaviors (e.g., risky sexual behaviors), mental health (internalizing symptoms, externalizing behaviors, PTSD) and substance use. At 12-month follow-up, there were significant within group reductions in both groups for all outcomes, with the only significant between group difference being for substance use, in which OVC who received TF-CBT had significantly greater reductions than OVC who received PC+. In a subgroup analysis of OVC with high levels of PTSD symptoms, TF-CBT was superior to PC + in reducing internalizing symptoms, functional impairment, and substance use. Findings support TF-CBT for reducing substance use among OVC. Subgroup analysis results suggest that a robust intervention such as TF-CBT is warranted for OVC with significant mental and behavioral health comorbidities. The similar performance of TF-CBT and PC + in the overall sample for risky sexual behavior and mild mental health problems indicates that enhancing existing psychosocial programs, such as PC, with standard implementation factors like having a defined training and supervision schedule (as was done to create PC+) may improve the efficacy of HIV risk reduction efforts.Clinical Trials Number: NCT02054780.

Editorial: Prevention is the best cure - or is it? A cautionary tale.

In large parts of the Western world prevention is considered a necessary, core component of successful youth care practice. Yet, mental health problems in young people do not appear to have declined over the past decades. How to explain this paradox? In this editorial for the Journal of Child Psychology and Psychiatry, several possible explanations are explored, one of which centers around how prevention is being operationalized-primarily, nowadays, as a screen-and-resolve 'troubleshooting' approach, rather than as an approach that supports the development of good health, competence, and resilience.

Increasing chronic disease preventive care in community mental health services: clinician-generated strategies.

BACKGROUND: People with a mental health condition experience a high prevalence of chronic disease risk behaviours e.g., tobacco smoking and physical inactivity. Recommended 'preventive care' to address these risks is infrequently provided by community mental health services. This study aimed to elucidate, among community mental health managers and clinicians, suggestions for strategies to support provision of preventive care. METHODS: Three qualitative focus groups (n = 14 clinicians) were undertaken in one regional community mental health service to gather perspectives of barriers to preventive care provision, deductively coded against the domains of the Theoretical Domains Framework (TDF). Drawing on the learnings from the focus groups, individual interviews (n = 15 managers and clinicians) were conducted in two services to identify suggestions for strategies to increase preventive care. Strategies were inductively coded and mapped into TDF domains. RESULTS: Barriers were identified across a wide range of TDF domains, most notably knowledge and environmental context and resources. Nine strategies were identified across three themes: training, resources and systems changes; mapping to all 14 TDF domains. CONCLUSION: Future research seeking to increase implementation of preventive care may be guided by these findings. There is need for greater recognition and resourcing of preventive care as a priority and integral component of mental health treatment.

Wellbeing-responsive community: a growth target for intentional mental health promotion.

With mental illness remaining a significant burden of disease, there is an ongoing need for community-based health promotion, prevention, and responses (or "mental health promotion activities"). The health promotion, community development, and positive psychology literature identifies significant heterogeneity in the design and delivery of these activities. This variability spans: (1) individual vs. group outcomes, (2) psychological vs. sociological determinants of change, (3) promoting wellbeing vs. reducing mental health symptoms, and (4) the degree activities are contextualized vs. standardized in design and delivery. Mental health promotion activities do not easily accomplish this level of complexity within design and implementation. This has led to the emergence of the complexity-informed health promotion literature and the need for innovative tools, methods, and theories to drive this endeavor. This article directly responds to this call. It introduces "wellbeing-responsive community": a vision and outcome hierarchy (or growth target) for intentionally delivered mental health promotion. The construct enables the design and implementation of interventions that intentionally respond to complexity and contextualization through the drivers of co-creation, intentionality, and local empowerment. It represents a community (support team, programme, agency, network, school, or region) that has the shared language, knowledge, methods, and skills to work together in shared intent. In other words, to integrate best-practice science with their local knowledge systems and existing strengths, and intentionally co-create and deliver contextualized wellbeing solutions at both the individual and community levels that span the "system" (e.g., whole-of-community) to the "moment" (e.g., intentional support and care). Co-creation, as applied through a transdisciplinary lens, is emerging as an evidence-based method to respond to complexity. This article describes the rationale and evidence underpinning the conceptualization of a wellbeing-responsive community through the integration of three key disciplines: (1) positive psychology, (2) ecological or systems approaches, and (3) intentional practice (implementation science). A definitional, contextual, and applied overview of the wellbeing-responsive community is provided, including a hierarchy of outcomes and associated definitions. Its purported application across education, mental health, community service, and organizational settings is discussed, including its potential role in making complexity-informed health promotion practical for all knowledge users.

Population-level effectiveness of alternative approaches to preventing mental disorders in adolescents and young adults.

Preventive interventions that are effective in reducing the incidence of mental disorders in adolescence and early adulthood may impact substantially on lifetime economic, educational, and health outcomes; however, relatively few studies have examined the capacity of alternative approaches to preventing youth mental disorders (specifically, universal, selective, and indicated prevention) to reduce disorder incidence at a population level. Using a dynamic model of the onset of non-specific, relatively mild symptoms and progression to more severe disease, we show that: (1) indicated preventive interventions, targeting adolescents and young adults experiencing subthreshold symptoms, may often be more effective in reducing mental disorder prevalence than universal interventions delivered to the general population (contrary to the widely accepted view that a 'high risk' prevention strategy, focussing on those individuals with the greatest risk of developing a disorder, will generally be less effective than a whole-population strategy); and (2) the ability of selective preventive interventions (targeting vulnerable, asymptomatic youth) to alter the prevalence of mental disorders is severely restricted by an inverse relationship between the prevalence of significant risk factors for mental illness and the relative risk of developing symptoms.