The Global Burden of Mental & Substance Use Disorders

Findings from the Global Burden of Disease Study

2010

Professor Harvey Whiteford

Queensland Centre for Mental Health Research

School of Population Health, The University of Queensland

Brisbane, Australia

Outline

1.  The Global Burden of Disease Study (GBD)

2.  Calculation of disability-adjusted life years (DALYs)

a)  Years of life lost due to premature mortality (YLLs)

b)  Years lived with disability (YLDs)

3.  Results:

a)  DALYs

b)  YLDs

c)  YLLs

4.  Implications for global health

The Global Burden of Disease Study

Institute for Health Metrics and Evaluation. DALY - GBD 2010 Poster. Washington, USA: Institute for Health Metrics and Evaluation; 2012.

The Global Burden of Disease Study (GBD) aims to quantifying the global burden attributable to different diseases, injuries, and risks.

DALY = YLD + YLL

GBD 1990 The first GBD study, GBD 1990, quantified burden for 107 causes across 8 world regions.

GBD 1990 included these disorders which grouped under neuropsychiatric

disorders:

•  Unipolar major depression

•  Anxiety disorders (GAD, PTSD and panic disorder separately)

•  Bipolar disorder

•  Schizophrenia

•  Drug use

•  Alcohol use

GBD 1990 found depression to be the leading cause of disability (YLDs) .

5 of the 10 leading causes of global disability were mental and substance use

disorders.

Murray CJL, Lopez AD, eds. The Global Burden of Disease: a comprehensive assessment of mortality and disability from diseases, injuries, and risk factors in 1990 and projected to 2020. USA: World Health Organization, Harvard School of Public Health, World Bank.; 1996. Global burden of disease and injury series; No. Volume 1.

GBD 2010 GBD 2010 quantified burden for 291 diseases, injuries and risks for 187 countries, 21 world regions, 6 super-regions and the world.

This included 13 mental disorders categorised into 9 groups:

•  Depressive disorders – MDD and dysthymia •  Anxiety disorders

•  Schizophrenia

•  Bipolar disorder •  Eating disorders – anorexia and bulimia

•  Disruptive behavioural disorders – conduct disorder and ADHD •  Pervasive developmental disorders – autism and Asperger’s disorder

•  Idiopathic intellectual disability

•  Other mental disorders

Murray CJL, Ezzati M, Flaxman AD, Lim S, Lozano R, Michaud C, et al. GBD 2010: design, definitions, and metrics. The Lancet 2012;380:2063-2066.

GBD 2010 continued GBD 2010 quantified burden for 291 diseases, injuries and risks for 187 countries, 21 world regions, 6 super-regions and the world.

This also included five drug disorders along with alcohol use disorders:

•  Cannabis

•  Cocaine

•  Amphetamines

•  Opioids

•  Alcohol use disorders

Murray CJL, Ezzati M, Flaxman AD, Lim S, Lozano R, Michaud C, et al. GBD 2010: design, definitions, and metrics. The Lancet 2012;380:2063-2066.

Calculation of YLLs and YLDs YLLs = Attributable Deaths x Life Expectancy

YLDs = Prevalent Cases x Disability Weight Prevalent cases:

•  Systematic review and extraction of epidemiological data.

•  Modelling the epidemiological data in DisMod-MR.

•  Use of prevalence output and population data to ascertain prevalent cases.

Disability weights:

•  Disability was defined as ‘any short or long term health loss due to a particular cause’.

•  Population and online surveys with lay descriptions presented as pairwise

comparisons.

•  Fixed on a 0 to 1 scale.

•  Adjusted for severity distributions and comorbidity.

Vos T, Flaxman AD, Naghavi M, et al. Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990-2010: a systematic analysis for the Global Burden of Disease Study 2010. The Lancet. 2012; 380(9859):2163-2196.

Total DALYs (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Mental & Substance Use Disorder DALYs (2010)

Whiteford HA, Degenhardt L, Rehm JT, et al. The Global Burden of Mental and Substance Use Disorders, 2010. The Lancet. 2013; In press.

Total DALYs (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Developed

Developing

DALY Rates and Proportions

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

This map shows the age-standardised DALY rates per 100,000 people for mental and substance use disorders.

DALY Rates By Country (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Total DALYs (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Total YLDs (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Total YLDs (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Total YLLs (2010)

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Global Rankings (2010) DALYS YLDs YLLs

Institute for Health Metrics and Evaluation. GBD Compare. 2013; http://viz.healthmetricsandevaluation.org/gbd-compare/.

Implications •  Global disease burden has shifted:

•  From communicable to non-communicable diseases

•  From YLLs to YLDs

•  Mental and substance use disorders make up a significant component of

the changing global picture.

•  While comprehensive, the mental and substance use disorders presented

here do not represent the full picture of mental and substance use burden.

•  Current estimates need to be regularly updated.

Whiteford HA, Degenhardt L, Rehm JT, et al. The Global Burden of Mental and Substance Use Disorders, 2010. The Lancet. 2013; In press.