Elsevier

The Lancet

Volume 382, Issue 9904, 9–15 November 2013, Pages 1575-1586
The Lancet

Articles
Global burden of disease attributable to mental and substance use disorders: findings from the Global Burden of Disease Study 2010

https://doi.org/10.1016/S0140-6736(13)61611-6Get rights and content

Summary

Background

We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to estimate the burden of disease attributable to mental and substance use disorders in terms of disability-adjusted life years (DALYs), years of life lost to premature mortality (YLLs), and years lived with disability (YLDs).

Methods

For each of the 20 mental and substance use disorders included in GBD 2010, we systematically reviewed epidemiological data and used a Bayesian meta-regression tool, DisMod-MR, to model prevalence by age, sex, country, region, and year. We obtained disability weights from representative community surveys and an internet-based survey to calculate YLDs. We calculated premature mortality as YLLs from cause of death estimates for 1980–2010 for 20 age groups, both sexes, and 187 countries. We derived DALYs from the sum of YLDs and YLLs. We adjusted burden estimates for comorbidity and present them with 95% uncertainty intervals.

Findings

In 2010, mental and substance use disorders accounted for 183·9 million DALYs (95% UI 153·5 million–216·7 million), or 7·4% (6·2–8·6) of all DALYs worldwide. Such disorders accounted for 8·6 million YLLs (6·5 million–12·1 million; 0·5% [0·4–0·7] of all YLLs) and 175·3 million YLDs (144·5 million–207·8 million; 22·9% [18·6–27·2] of all YLDs). Mental and substance use disorders were the leading cause of YLDs worldwide. Depressive disorders accounted for 40·5% (31·7–49·2) of DALYs caused by mental and substance use disorders, with anxiety disorders accounting for 14·6% (11·2–18·4), illicit drug use disorders for 10·9% (8·9–13·2), alcohol use disorders for 9·6% (7·7–11·8), schizophrenia for 7·4% (5·0–9·8), bipolar disorder for 7·0% (4·4–10·3), pervasive developmental disorders for 4·2% (3·2–5·3), childhood behavioural disorders for 3·4% (2·2–4·7), and eating disorders for 1·2% (0·9–1·5). DALYs varied by age and sex, with the highest proportion of total DALYs occurring in people aged 10–29 years. The burden of mental and substance use disorders increased by 37·6% between 1990 and 2010, which for most disorders was driven by population growth and ageing.

Interpretation

Despite the apparently small contribution of YLLs—with deaths in people with mental disorders coded to the physical cause of death and suicide coded to the category of injuries under self-harm—our findings show the striking and growing challenge that these disorders pose for health systems in developed and developing regions. In view of the magnitude of their contribution, improvement in population health is only possible if countries make the prevention and treatment of mental and substance use disorders a public health priority.

Funding

Queensland Department of Health, National Health and Medical Research Council of Australia, National Drug and Alcohol Research Centre-University of New South Wales, Bill & Melinda Gates Foundation, University of Toronto, Technische Universität, Ontario Ministry of Health and Long Term Care, and the US National Institute of Alcohol Abuse and Alcoholism.

Introduction

Historically, mental and substance use disorders were not a global health priority, especially when compared with communicable diseases and non-communicable diseases such as cancer or cardiovascular disease. Services for mental and substance use disorders have typically been neglected, and in many countries were segregated from mainstream health care with resourcing not commensurate with the burden.1, 2 Since the 1993 World Development Report3 by the World Bank, global attention has been focused on the relative burden associated with disease morbidity, rather than mortality alone. The move to incorporate the effects of disease morbidity has been key in emphasising the importance of mental and substance use disorders. An international effort to improve the mental health of populations around the world is now underway.4

The first Global Burden of Disease study in 1990 (GBD 1990), showed that neuropsychiatric disorders—a grouping that included neurological disorders and dementia as well as mental and substance use disorders—accounted for more than a quarter of all non-fatal burden, measured in years lived with disability (YLD).5 Five of the top ten causes of disability were included in the neuropsychiatric disorder category. Depression was the most disabling disorder worldwide measured in YLDs, and the fourth leading cause of overall disease burden measured in disability-adjusted life years (DALYs), which combines premature mortality as years of life lost (YLLs) and disability as YLDs.6 Estimates for selected disorders were revised in the early 2000s with updated epidemiological evidence and, for some disorders, modified health states and disability weights.7, 8 These selected disorders were mood disorders (depression and bipolar disorder), anxiety disorders (panic disorder, obsessive-compulsive disorder, and post-traumatic stress disorder), and schizophrenia.9 Drug use disorders were shown as a combined estimate including harmful use and dependence of opioids and cocaine. A single estimate was also given for alcohol use disorders which encompassed alcohol-induced psychoses, alcohol dependence, and alcohol abuse.5 A notable limitation was the failure to capture some common disorders (eg, cannabis dependence, generalised anxiety disorder, eating disorders, and most childhood onset disorders).

In 2007, a new GBD study was launched10 and high level results for the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) were reported in December, 2012.11, 12, 13, 14, 15, 16, 17 GBD 2010 was a comprehensive reanalysis of burden for 291 causes, 20 age groups, both sexes, and 187 countries in 21 world regions for 1990 and 2010. The definition of world regions was based on geographical proximity and epidemiological similarity in terms of child and adult mortality.11 These regions were further grouped into seven super-regions (based on cause of death patterns) to permit imputation of data for regions where no information was available

The number of specific mental and substance use disorders was expanded in GBD 2010 to include 20 disorders, consisting of all anxiety disorders (compared with three in the original study), eating disorders (anorexia nervosa and bulimia nervosa), childhood behavioural disorders (attention-deficit/hyperactivity disorder and conduct disorder), pervasive developmental disorders (autism and Asperger's syndrome), and idiopathic intellectual disability, a residual category capturing intellectual disability not attributed to any of the other diseases and injuries. Existing disorder categories were also expanded; for example, bipolar disorder captured cyclothymic disorder in 2010 and unipolar depression was modelled as major depressive disorder and dysthymia. Substance use disorders were expanded to include burden for alcohol use disorders (alcohol dependence and fetal alcohol syndrome) and illicit drug use disorders (opioid dependence, cannabis dependence, cocaine dependence, and amphetamine dependence). Two residual categories capturing other mental and substance use disorders were also estimated. Harmful use or abuse of drugs and alcohol were not included in GBD 2010. The burden estimation techniques changed substantially in GBD 2010: notably, prevalent rather than incident based YLDs were estimated without age weighting and discounting. Because of changes in methodology, estimates for the years 1990 and 2010 were re-calculated for GBD 2010 to allow meaningful comparisons in burden across time.

In this report, we aimed to summarise fatal, non-fatal, and total burden for eleven classes of mental and substance use disorders for 2010 with reference to changes in burden since 1990.

Section snippets

Definitions of mental and substance use disorders

To be included, specific mental and substance use disorders had to meet the threshold for a case according to criteria described in the Diagnostic and Statistical Manual of Mental Disorders (DSM)18 or the International Classification of Diseases (ICD).19 To obtain the most comprehensive dataset possible, we included all clinically relevant case definitions that would map to DSM or ICD diagnostic criteria. We tested for differential case-finding properties of different diagnostic criteria in a

Results

Worldwide, mental and substance use disorders accounted for 183·9 million DALYs (95% UI 153·5 million–216·7 million), or 7·4% (6·2–8·6) of total disease burden in 2010 (table). Overall, mental and substance use disorders were the fifth leading disorder category of global DALYs (table).

Within the mental and substance use disorders group, depressive disorders accounted for most DALYs, followed by anxiety disorders, drug use disorders, and alcohol use disorders (figure 1). Eating disorders,

Discussion

Mental and substance use disorders are notable contributors to the global burden of disease, directly accounting for about 7·4% of disease burden worldwide (panel). These disorders were responsible for more of the global burden than were HIV/AIDS and tuberculosis, diabetes, or transport injuries. GBD 2010 provides a comprehensive picture of burden compared with previous estimates in view of the wide range of disorders included, improved definitions, data, and methods used. The inclusion of

References (77)

  • L Degenhardt et al.

    What data are available on the extent of illicit drug use and dependence globally? Results of four systematic reviews

    Drug Alcohol Depend

    (2011)
  • L Degenhardt et al.

    Mortality among cocaine users: a systematic review of cohort studies

    Drug Alcohol Depend

    (2011)
  • AJ Ferrari et al.

    A systematic review of the global distribution and availability of prevalence data for bipolar disorder

    J Affect Disord

    (2011)
  • DP Schopflocher et al.

    What difference does dependent comorbidity make in burden of disease studies? A survey analysis and simulation. Global Health Metrics and Evaluation. Seattle, USA

    Lancet

    (2013)
  • BM Mathers et al.

    HIV prevention, treatment, and care services for people who inject drugs: a systematic review of global, regional, and national coverage

    Lancet

    (2010)
  • PS Wang et al.

    Use of mental health services for anxiety, mood, and substance disorders in 17 countries in the WHO world mental health surveys

    Lancet

    (2007)
  • J Rehm et al.

    Modeling the impact of alcohol dependence on mortality burden and the effect of available treatment interventions in the European Union

    Eur Neuropsychopharmacol

    (2013)
  • S Saxena et al.

    Resources for mental health: scarcity, inequity, and inefficiency

    Lancet

    (2007)
  • A Kleinman

    Global mental health: a failure of humanity

    Lancet

    (2009)
  • V Patel et al.

    Treatment and prevention of mental disorders in low-income and middle-income countries

    Lancet

    (2007)
  • WA Tol et al.

    Mental health and psychosocial support in humanitarian settings: linking practice and research

    Lancet

    (2011)
  • B Saraceno et al.

    Barriers to improvement of mental health services in low-income and middle-income countries

    Lancet

    (2007)
  • J Eaton et al.

    Scale up of services for mental health in low-income and middle-income countries

    Lancet

    (2011)
  • S Moussavi et al.

    Depression, chronic diseases, and decrements in health: results from the World Health Surveys

    Lancet

    (2007)
  • Z Li et al.

    Attributable risk of psychiatric and socio-economic factors for suicide from individual-level, population-based studies: a systematic review

    Soc Sci Med

    (2011)
  • Z Li et al.

    Attributable risk of psychiatric and socio-economic factors for suicide from individual-level, population-based studies: a systematic review

    Soc Sci Med

    (2011)
  • MR Phillips et al.

    Prevalence, treatment, and associated disability of mental disorders in four provinces in China during 2001-05: an epidemiological survey

    Lancet

    (2009)
  • SM Chang et al.

    Cross-national difference in the prevalence of depression caused by the diagnostic threshold

    J Affect Disord

    (2008)
  • L Degenhardt et al.

    Estimating the burden of disease attributable to illicit drug use and mental disorders: what is ‘Global Burden of Disease 2005’ and why does it matter?

    Addiction

    (2009)
  • TB Ustün

    The global burden of mental disorders

    Am J Public Health

    (1999)
  • World Development Report 1993. Investing in health: world development indicators

    (1993)
  • CJ Murray et al.

    Quantifying disability: data, methods and results

    Bull World Health Organ

    (1994)
  • AD Lopez et al.

    The global burden of disease, 1990–2020

    Nat Med

    (1998)
  • CD Mathers et al.

    Global Burden of Disease 2000: version 2 methods and results

    (2002)
  • The global burden of disease: 2004 update

    (2008)
  • Diagnostic and statistical manual of mental disorders (DSM-IV-TR)

    (2000)
  • The ICD-10 classification of mental and behavioural disorders: diagnostic criteria for research

    (1993)
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