Globally, mental health disorders and substance use disorders (SUDs) contribute significantly to the overall burden of disease, with many of these conditions emerging during adolescence. Once dismissed as mere “growing pains”, these conditions significantly affect quality of life and social functioning. It has previously been estimated that each year, around 25% of adolescents experience a mental health disorder, increasing to 33% over their lifetime (Kessler et al., 2007).
As emphasised by Beth Cumber in her recent Mental Elf blog, early intervention is necessary for improving mental health outcomes in this population. Similarly, in his 2022 blog, Alejandro Arguelles Bullon highlighted the importance of age-stratified analyses to understand risk patterns during adolescence, as it allows researchers to identify particular points of vulnerability and potential intervention.
Against this backdrop, Kieling et al. (2024) used the latest 2019 Global Burden of Disease (GBD) data to analyse the global prevalence and health burden of mental health disorders and substance use disorders (SUDs) among different age groups across childhood and adolescence. Their findings reveal critical characteristics of mental health disorders during adolescence and offer clear directions for early intervention, providing vital evidence for policymakers and healthcare workers.
The importance of early intervention and prevention in child and adolescent mental health is increasingly recognised, with age-stratified analyses allowing researchers to identify trends and points of intervention.
Methods
The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) is a huge population study that started in the early 1990s to quantify levels and trends in health across the globe.
The current study by Kieling et al. (2024) analysed the global prevalence and health burden of mental disorders and SUDs among 2,516 million individuals aged 5–24 years using data from the 2019 GBD study. Data sources included national health surveys, hospital records, and international reports. Data were stratified by distinct age groups (5–9, 10–14, 15–19, and 20–24 years) and gender. Findings were cross-validated with independent datasets to ensure reliability. The Cause of Death Ensemble Model (CODEm) was conducted to adjust for comorbidities. Health burden was quantified using Years Lived with Disability (YLDs).
Results
In 2019, 11.63% of individuals aged 5-24 years (approximately 293 million) had at least one mental health disorder, while 1.22% (approximately 31 million) had a SUD (see Table 1 below). Anxiety disorders were the most prevalent (3.35%; 84 million), and schizophrenia was the least common (0.08%; 2 million). Boys showed higher rates of neurodevelopmental disorders such as autism and attention-deficit hyperactivity disorder (ADHD), while girls had greater prevalence of anxiety, mood, and eating disorders.
Regarding health burden, mental health disorders accounted for 20.27% (31.14 million of 153.59 million) of YLDs in children and youths aged 5-24 years, the highest among all health conditions. SUDs contributed to 4.30 million YLDs. YLDs increased dramatically with age, with almost 5-fold increases in the number of YLDs in the age 20-24 years, compared to the age 5-9 years. The most stark increase was for depressive disorders, where the number of YLDs rose 35-fold from 5-9 years to 20-24 years.
From a broader life course perspective across all ages, 24.85% (31.14 million of 125.29 million) of total YLDs associated with mental disorders occur in the age 5 to 24 years, highlighting their significant burden compared to other health conditions like cardiovascular diseases (5.30%) and diabetes (3.15%).
Table 1. Prevalence of at least one mental health disorder across age groups
| Age group (years) | Prevalence (% [95% CI]) |
| 5 to 9 | 6.81% [5.60 to 8.03] |
| 10 to 14 | 12.42% [10.57 to 14.45] |
| 15 to 19 | 13.96% [12.37 to 15.78] |
| 20 to 24 | 13.63% [11.91 to 15.53] |
| 5 to 24 (all) | 11.63% (weighted mean) |
In 2019, approximately 293 million children and adolescents aged 5-24 years experienced at least one mental health disorder, with anxiety disorders being the most prevalent.
Conclusions
This study by Kieling and colleagues (2024) highlights the global prevalence of mental health disorders in children and adolescents aged 5–24 years, with anxiety disorders and mood disorders being the primary contributors. Mental health disorders account for 20.27% of non-fatal health burdens from all GBD disorders in individuals aged 5-24 years. Moreover, over the life course, 24.85% of all health burden attributable to mental health disorders was found in people aged 5-24 years, reversing the typical patterns observed in other health conditions such as cardiovascular diseases and diabetes.
These mental health conditions have a profound impact on education, social participation, and economic opportunities, with the burden particularly high in low- and middle-income countries (LMICs). As such, this study emphasises the pressing need for an increased focus on early screening and intervention efforts, age-specific resource allocation, and prioritising adolescent mental health as a global health concern. Policymakers are urged to address these challenges through evidence-based interventions and sustainable mental health policies.
Between the ages of 5-9 and 20-24 years, the prevalence of having at least one mental health disorder doubles, highlighting the importance of early intervention and prevention efforts during this developmental period.
Strengths and limitations
Strengths
- The study adopts an age-stratified analysis, offering detailed insights into mental health disorder prevalence and health burden across distinct age groups across childhood and adolescence. It also provides evidence-based recommendations, emphasizing the importance of age-specific data for resource allocation and targeted interventions.
- The study used the data from GBD, which is collected from across 204 countries and regions and includes a wide range of data sources, such as systematic reviews, government reports, and international databases. This worldwide coverage allows for cross-regional comparisons, supporting more inclusive and culturally sensitive health policies.
- The study employs a comorbidity adjustment mechanism to address the overlap of multiple disorders within individuals, reducing bias and ensuring independent and accurate estimates of each disorder’s burden across age, gender, and region.
Limitations
- Data from LMICs are limited in quality, with over 170 million children and youths living in data-scarce regions. Additionally, high-risk groups such as LGBTQIA+ youth and Indigenous adolescents are underrepresented. Such regional differences in data collection and reporting further affect cross-region comparability.
- Data sources vary by age group, with parental reports used for younger children and self-reports for adolescents, causing inconsistencies in data interpretation. Exclusion of subclinical presentations also potentially underestimates the true burden of mental health issues.
- The study relies on 2019 cross-sectional data, limiting insights into longitudinal impacts of these mental health conditions. Furthermore, it does not account for the impact of the COVID-19 pandemic, which had a widespread negative impact on the mental health of children and adolescents.
- Variations in diagnostic standards, cultural perceptions, and reporting practices across regions may introduce observer bias, affecting the accuracy and comparability of prevalence estimates. Although the data were adjusted to account for known biases, there remains some uncertainty about their accuracy.
While the use of a global dataset allows for cross-regional comparisons, there is limited data from low- and middle-income countries, alongside underrepresentation from high-risk groups.
Implications for practice
This study highlights the urgent need for early intervention and age-specific mental health strategies at a global scale. Policies must prioritise adequate funding, stigma reduction, and accessible healthcare for children and adolescents, especially in LMICs.
During my internship at a psychiatric hospital in China, I observed that parents often sought professional help only when their children’s academic performance had declined, and after a critical incident, such as self-harm or suicide. Earlier signs of mental distress were overlooked or not recognised. This lack of awareness may lead to delayed intervention, which can further negatively impact academic performance, emotional stability, interpersonal relationships, and personal development, all of which I witnessed during my intervention.
Additionally, mental health stigma remains a major barrier to timely access to professional help (Golberstein et al., 2008). Addressing mental health in childhood and adolescence requires not only clinical interventions but cultural shifts—fostering awareness, acceptance, and proactive support systems throughout society. This necessitates increased communication between different systems, such as schools and healthcare services.
During my internship, I noticed that schools often lacked the diagnostic tools and training necessary to identify and address mental health issues at an early stage, whereas healthcare systems frequently operated in isolation, with limited communication and collaboration with schools and families. This caused many missed opportunities for early intervention.
In order to increase timely access to mental health support, we need to improve awareness of the early signs of mental distress in children and adolescents.
Statement of interests
None.
Links
Primary paper
Kieling, C., Buchweitz, C., Caye, A., Silvani, J., Ameis, S. H., Brunoni, A. R., … & Szatmari, P. (2024). Worldwide prevalence and disability from mental disorders across childhood and adolescence: evidence from the global burden of disease study. JAMA Psychiatry, 81(4), 347-356.
Other references
Bullon, A. A. (2022). Global burden of disease from mental disorders remains high. The Mental Elf.
Cumber, B. (2024). Prevention is where it’s at for children and young people’s mental health. The Mental Elf.
Golberstein, E., Eisenberg, D., & Gollust, S. E. (2008). Perceived stigma and mental health care seeking. Psychiatric Services, 59(4), 392-399.
Kessler, R. C., Berglund, P., Demler, O., Jin, R., Merikangas, K. R., & Walters, E. E. (2005). Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Archives of General Psychiatry, 62(6), 593-602.
