The clinical implications of climate change for mental health.

Climate change affects mental health through multiple pathways, including direct and indirect impacts, physical health and awareness of the climate crisis. Climate change increases the magnitude and frequency of extreme events with little or no time for recovery. This Review aims to provide an overview of the current evidence to inform the mental health field's response to climate change. While further innovation is needed, promising approaches for health professionals are identified at the levels of interventions for individuals, community and system-wide responses, and advocacy and education. Health worker training is important, so we offer guidance on mental health assessment and clinical risks from climate change. We also outline strategies to enhance individual and community psychological resilience and promising approaches to working with people experiencing emerging climate-related disorders. Beyond clinical care, mental health professionals can lead on climate action and sustainability in health care and can research and educate on the health effects of climate change.

A comprehensive analysis of mortality-related health metrics associated with mental disorders: a nationwide, register-based cohort study.

BACKGROUND: Systematic reviews have consistently shown that individuals with mental disorders have an increased risk of premature mortality. Traditionally, this evidence has been based on relative risks or crude estimates of reduced life expectancy. The aim of this study was to compile a comprehensive analysis of mortality-related health metrics associated with mental disorders, including sex-specific and age-specific mortality rate ratios (MRRs) and life-years lost (LYLs), a measure that takes into account age of onset of the disorder. METHODS: In this population-based cohort study, we included all people younger than 95 years of age who lived in Denmark at some point between Jan 1, 1995, and Dec 31, 2015. Information on mental disorders was obtained from the Danish Psychiatric Central Research Register and the date and cause of death was obtained from the Danish Register of Causes of Death. We classified mental disorders into ten groups and causes of death into 11 groups, which were further categorised into natural causes (deaths from diseases and medical conditions) and external causes (suicide, homicide, and accidents). For each specific mental disorder, we estimated MRRs using Poisson regression models, adjusting for sex, age, and calendar time, and excess LYLs (ie, difference in LYLs between people with a mental disorder and the general population) for all-cause mortality and for each specific cause of death. FINDINGS: 7 369 926 people were included in our analysis. We found that mortality rates were higher for people with a diagnosis of a mental disorder than for the general Danish population (28·70 deaths [95% CI 28·57-28·82] vs 12·95 deaths [12·93-12·98] per 1000 person-years). Additionally, all types of disorders were associated with higher mortality rates, with MRRs ranging from 1·92 (95% CI 1·91-1·94) for mood disorders to 3·91 (3·87-3·94) for substance use disorders. All types of mental disorders were associated with shorter life expectancies, with excess LYLs ranging from 5·42 years (95% CI 5·36-5·48) for organic disorders in females to 14·84 years (14·70-14·99) for substance use disorders in males. When we examined specific causes of death, we found that males with any type of mental disorder lost fewer years due to neoplasm-related deaths compared with the general population, although their cancer mortality rates were higher. INTERPRETATION: Mental disorders are associated with premature mortality. We provide a comprehensive analysis of mortality by different types of disorders, presenting both MRRs and premature mortality based on LYLs, displayed by age, sex, and cause of death. By providing accurate estimates of premature mortality, we reveal previously underappreciated features related to competing risks and specific causes of death. FUNDING: Danish National Research Foundation.

Diseases, Injuries, and Risk Factors in Child and Adolescent Health, 1990 to 2017: Findings From the Global Burden of Diseases, Injuries, and Risk Factors 2017 Study.

Importance: Understanding causes and correlates of health loss among children and adolescents can identify areas of success, stagnation, and emerging threats and thereby facilitate effective improvement strategies. Objective: To estimate mortality and morbidity in children and adolescents from 1990 to 2017 by age and sex in 195 countries and territories. Design, Setting, and Participants: This study examined levels, trends, and spatiotemporal patterns of cause-specific mortality and nonfatal health outcomes using standardized approaches to data processing and statistical analysis. It also describes epidemiologic transitions by evaluating historical associations between disease indicators and the Socio-Demographic Index (SDI), a composite indicator of income, educational attainment, and fertility. Data collected from 1990 to 2017 on children and adolescents from birth through 19 years of age in 195 countries and territories were assessed. Data analysis occurred from January 2018 to August 2018. Exposures: Being under the age of 20 years between 1990 and 2017. Main Outcomes and Measures: Death and disability. All-cause and cause-specific deaths, disability-adjusted life years, years of life lost, and years of life lived with disability. Results: Child and adolescent deaths decreased 51.7% from 13.77 million (95% uncertainty interval [UI], 13.60-13.93 million) in 1990 to 6.64 million (95% UI, 6.44-6.87 million) in 2017, but in 2017, aggregate disability increased 4.7% to a total of 145 million (95% UI, 107-190 million) years lived with disability globally. Progress was uneven, and inequity increased, with low-SDI and low-middle-SDI locations experiencing 82.2% (95% UI, 81.6%-82.9%) of deaths, up from 70.9% (95% UI, 70.4%-71.4%) in 1990. The leading disaggregated causes of disability-adjusted life years in 2017 in the low-SDI quintile were neonatal disorders, lower respiratory infections, diarrhea, malaria, and congenital birth defects, whereas neonatal disorders, congenital birth defects, headache, dermatitis, and anxiety were highest-ranked in the high-SDI quintile. Conclusions and Relevance: Mortality reductions over this 27-year period mean that children are more likely than ever to reach their 20th birthdays. The concomitant expansion of nonfatal health loss and epidemiological transition in children and adolescents, especially in low-SDI and middle-SDI countries, has the potential to increase already overburdened health systems, will affect the human capital potential of societies, and may influence the trajectory of socioeconomic development. Continued monitoring of child and adolescent health loss is crucial to sustain the progress of the past 27 years.

Global Epidemiology and Burden of Schizophrenia: Findings From the Global Burden of Disease Study 2016.

Introduction: The global burden of disease (GBD) studies have derived detailed and comparable epidemiological and burden of disease estimates for schizophrenia. We report GBD 2016 estimates of schizophrenia prevalence and burden of disease with disaggregation by age, sex, year, and for all countries. Method: We conducted a systematic review to identify studies reporting the prevalence, incidence, remission, and/or excess mortality associated with schizophrenia. Reported estimates which met our inclusion criteria were entered into a Bayesian meta-regression tool used in GBD 2016 to derive prevalence for 20 age groups, 7 super-regions, 21 regions, and 195 countries and territories. Burden of disease estimates were derived for acute and residual states of schizophrenia by multiplying the age-, sex-, year-, and location-specific prevalence by 2 disability weights representative of the disability experienced during these states. Findings: The systematic review found a total of 129 individual data sources. The global age-standardized point prevalence of schizophrenia in 2016 was estimated to be 0.28% (95% uncertainty interval [UI]: 0.24-0.31). No sex differences were observed in prevalence. Age-standardized point prevalence rates did not vary widely across countries or regions. Globally, prevalent cases rose from 13.1 (95% UI: 11.6-14.8) million in 1990 to 20.9 (95% UI: 18.5-23.4) million cases in 2016. Schizophrenia contributes 13.4 (95% UI: 9.9-16.7) million years of life lived with disability to burden of disease globally. Conclusion: Although schizophrenia is a low prevalence disorder, the burden of disease is substantial. Our modeling suggests that significant population growth and aging has led to a large and increasing disease burden attributable to schizophrenia, particularly for middle income countries.

The State of US Health, 1990-2016: Burden of Diseases, Injuries, and Risk Factors Among US States.

Introduction: Several studies have measured health outcomes in the United States, but none have provided a comprehensive assessment of patterns of health by state. Objective: To use the results of the Global Burden of Disease Study (GBD) to report trends in the burden of diseases, injuries, and risk factors at the state level from 1990 to 2016. Design and Setting: A systematic analysis of published studies and available data sources estimates the burden of disease by age, sex, geography, and year. Main Outcomes and Measures: Prevalence, incidence, mortality, life expectancy, healthy life expectancy (HALE), years of life lost (YLLs) due to premature mortality, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 333 causes and 84 risk factors with 95% uncertainty intervals (UIs) were computed. Results: Between 1990 and 2016, overall death rates in the United States declined from 745.2 (95% UI, 740.6 to 749.8) per 100 000 persons to 578.0 (95% UI, 569.4 to 587.1) per 100 000 persons. The probability of death among adults aged 20 to 55 years declined in 31 states and Washington, DC from 1990 to 2016. In 2016, Hawaii had the highest life expectancy at birth (81.3 years) and Mississippi had the lowest (74.7 years), a 6.6-year difference. Minnesota had the highest HALE at birth (70.3 years), and West Virginia had the lowest (63.8 years), a 6.5-year difference. The leading causes of DALYs in the United States for 1990 and 2016 were ischemic heart disease and lung cancer, while the third leading cause in 1990 was low back pain, and the third leading cause in 2016 was chronic obstructive pulmonary disease. Opioid use disorders moved from the 11th leading cause of DALYs in 1990 to the 7th leading cause in 2016, representing a 74.5% (95% UI, 42.8% to 93.9%) change. In 2016, each of the following 6 risks individually accounted for more than 5% of risk-attributable DALYs: tobacco consumption, high body mass index (BMI), poor diet, alcohol and drug use, high fasting plasma glucose, and high blood pressure. Across all US states, the top risk factors in terms of attributable DALYs were due to 1 of the 3 following causes: tobacco consumption (32 states), high BMI (10 states), or alcohol and drug use (8 states). Conclusions and Relevance: There are wide differences in the burden of disease at the state level. Specific diseases and risk factors, such as drug use disorders, high BMI, poor diet, high fasting plasma glucose level, and alcohol use disorders are increasing and warrant increased attention. These data can be used to inform national health priorities for research, clinical care, and policy.

The prevalence and burden of mental and substance use disorders in Australia: Findings from the Global Burden of Disease Study 2015.

OBJECTIVES: Timely and accurate assessments of disease burden are essential for developing effective national health policies. We used the Global Burden of Disease Study 2015 to examine burden due to mental and substance use disorders in Australia. METHODS: For each of the 20 mental and substance use disorders included in Global Burden of Disease Study 2015, systematic reviews of epidemiological data were conducted, and data modelled using a Bayesian meta-regression tool to produce prevalence estimates by age, sex, geography and year. Prevalence for each disorder was then combined with a disorder-specific disability weight to give years lived with disability, as a measure of non-fatal burden. Fatal burden was measured as years of life lost due to premature mortality which were calculated by combining the number of deaths due to a disorder with the life expectancy remaining at the time of death. Disability-adjusted life years were calculated by summing years lived with disability and years of life lost to give a measure of total burden. Uncertainty was calculated around all burden estimates. RESULTS: Mental and substance use disorders were the leading cause of non-fatal burden in Australia in 2015, explaining 24.3% of total years lived with disability, and were the second leading cause of total burden, accounting for 14.6% of total disability-adjusted life years. There was no significant change in the age-standardised disability-adjusted life year rates for mental and substance use disorders from 1990 to 2015. CONCLUSION: Global Burden of Disease Study 2015 found that mental and substance use disorders were leading contributors to disease burden in Australia. Despite several decades of national reform, the burden of mental and substance use disorders remained largely unchanged between 1990 and 2015. To reduce this burden, effective population-level preventions strategies are required in addition to effective interventions of sufficient duration and coverage.

Prevalence of mental, neurological, and substance use disorders in China and India: a systematic analysis.

BACKGROUND: Population-representative prevalence data for mental, neurological, and substance use disorders are essential for evidence-based decision making. As a background to the China-India Mental Health Alliance Series, we aim to examine the availability of data and report prevalence for the most common mental, neurological, and substance use disorders in China and India from the Global Burden of Disease study 2013 (GBD 2013). METHODS: In this systematic analysis, data sources were identified from GBD 2013 for the prevalence of mental, neurological, and substance use disorders in China and India published up to Dec 31, 2013. We calculated the proportion of the population represented by the data with the adjusted population coverage (APC) method adjusting for age, sex, and population size. We developed prevalence models with DisMod-MR 2.0, a Bayesian meta-regression instrument used to pool population-representative epidemiological data as part of GBD 2013. We report estimates and 95% uncertainly intervals (95% UI) for 15 mental, neurological, and substance use disorders for China and India in 1990 and 2013, and benchmark these against those for other BRICS countries (Brazil, Russia, and South Africa) in 2013. FINDINGS: Few population-representative data were found for the disorders, with an average coverage of 15% of the population of the Chinese mainland and 1% of the population of India. For men in both China and India, major depressive disorder, anxiety disorders, and alcohol dependence were the most common mental, neurological, and substance use disorders. Prevalence of major depressive disorder was 2·2% (95% UI 1·5-2·8) in Chinese men and 3·5% (2·4-4·6) in Indian men; prevalence of anxiety disorders was 2·0% (1·1-3·2) and 1·9% (1·2-2·3), respectively. For women, anxiety disorders, major depressive disorder, and dysthymia were the most common. Prevalence of major depressive disorder was 3·3% (2·3-4·1) in Chinese women and 4·7% (95% UI 3·3-6·2) in Indian women; prevalence of anxiety disorders was 3·3% (1·6-5·3) and 4·1% (3·3-5·0), respectively. Schizophrenia was more prevalent in China (0·5%, 95% UI 0·4-0·5) than in India (0·2%; 0·2-0·2). INTERPRETATION: More data for mental, neurological, and substance use disorders are needed for India and China but the large population and geographic scale of these countries present challenges to population-representative data collection. FUNDING: China-India Mental Health Alliance, China Medical Board.

Systematic review of interventions for Indigenous adults with mental and substance use disorders in Australia, Canada, New Zealand and the United States.

OBJECTIVE: The aim of this study was to systematically review the evidence-base for the effectiveness of culturally unadapted, culturally adapted and culture-based interventions for Indigenous adults with mental or substance use disorders. METHODS: We conducted a systematic search of scientific databases, government websites and web-based Indigenous research repositories. We sought studies using designs comparing an intervention group to a control/comparator group or pre- and post-test designs, published between 2000 and 2015 examining interventions to improve individual-level outcomes (e.g. remission, symptoms, quality of life, functioning) or service-level outcomes (e.g. number of interventions delivered) for Indigenous adults with mental or substance use disorders in Australia, Canada, New Zealand or the United States. RESULTS: A total of 16 studies met inclusion criteria. Virtually all North American studies (6 US and 1 Canadian) evaluated culturally unadapted interventions, all of which were interventions for substance use. Two-thirds of Australian and New Zealand studies evaluated culturally adapted interventions and included samples with mental disorders. Of eight culturally unadapted psychological/psychosocial, pharmacological and educational intervention studies, seven reported significant improvements on at least one measure of psychological well-being, mental health problem severity, or significantly reduced alcohol or illicit drug use. Of seven culturally adapted psychological/psychosocial intervention studies, all reported significant improvement on at least one measure of symptoms of mental illness, functioning, and alcohol use. One culture-based psychological/psychosocial intervention study significantly reduced problem severity in medical and psychiatric domains. CONCLUSION: There remains inconclusive evidence regarding interventions due to a small and methodologically weak evidence-base. The literature would be enhanced by intervention replication and outcome standardisation, validating the outcome instruments used in Indigenous populations, including sample size calculations and using stronger research designs (e.g. interrupted time-series designs). Robust implementation and outcomes research is needed to further progress evidence-based practice in Indigenous mental health.

The burden of mental, neurological, and substance use disorders in China and India: a systematic analysis of community representative epidemiological studies.

BACKGROUND: China and India jointly account for 38% of the world population, so understanding the burden attributed to mental, neurological, and substance use disorders within these two countries is essential. As part of the Lancet/Lancet Psychiatry China-India Mental Health Alliance Series, we aim to provide estimates of the burden of mental, neurological, and substance use disorders for China and India from the Global Burden of Disease Study 2013 (GBD 2013). METHODS: In this systematic analysis for community representative epidemiological studies, we conducted systematic reviews in line with PRISMA guidelines for community representative epidemiological studies. We extracted estimates of prevalence, incidence, remission and duration, and mortality along with associated uncertainty intervals from GBD 2013. Using these data as primary inputs, DisMod-MR 2.0, a Bayesian meta-regression instrument, used a log rate and incidence-prevalence-mortality mathematical model to develop internally consistent epidemiological models. Disability-adjusted life-year (DALY) changes between 1990 and 2013 were decomposed to quantify change attributable to population growth and ageing. We projected DALYs from 2013 to 2025 for mental, neurological, and substance use disorders using United Nations population data. FINDINGS: Around a third of global DALYs attributable to mental, neurological, and substance use disorders were found in China and India (66 million DALYs), a number greater than all developed countries combined (50 million DALYs). Disease burden profiles differed; India showed similarities with other developing countries (around 50% of DALYs attributable to non-communicable disease), whereas China more closely resembled developed countries (around 80% of DALYs attributable to non-communicable disease). The overall population growth in India explains a greater proportion of the increase in mental, neurological, and substance use disorder burden from 1990 to 2013 (44%) than in China (20%). The burden of mental, neurological, and substance use disorders is estimated to increase by 10% in China and 23% in India between 2013 and 2025. INTERPRETATION: The current and projected burden of mental, neurological, and substance use disorders in China and India warrants the urgent prioritisation of programmes focused on targeted prevention, early identification, and effective treatment. FUNDING: China Medical Board, Bill & Melinda Gates Foundation.

Global and National Burden of Diseases and Injuries Among Children and Adolescents Between 1990 and 2013: Findings From the Global Burden of Disease 2013 Study.

IMPORTANCE: The literature focuses on mortality among children younger than 5 years. Comparable information on nonfatal health outcomes among these children and the fatal and nonfatal burden of diseases and injuries among older children and adolescents is scarce. OBJECTIVE: To determine levels and trends in the fatal and nonfatal burden of diseases and injuries among younger children (aged <5 years), older children (aged 5-9 years), and adolescents (aged 10-19 years) between 1990 and 2013 in 188 countries from the Global Burden of Disease (GBD) 2013 study. EVIDENCE REVIEW: Data from vital registration, verbal autopsy studies, maternal and child death surveillance, and other sources covering 14,244 site-years (ie, years of cause of death data by geography) from 1980 through 2013 were used to estimate cause-specific mortality. Data from 35,620 epidemiological sources were used to estimate the prevalence of the diseases and sequelae in the GBD 2013 study. Cause-specific mortality for most causes was estimated using the Cause of Death Ensemble Model strategy. For some infectious diseases (eg, HIV infection/AIDS, measles, hepatitis B) where the disease process is complex or the cause of death data were insufficient or unavailable, we used natural history models. For most nonfatal health outcomes, DisMod-MR 2.0, a Bayesian metaregression tool, was used to meta-analyze the epidemiological data to generate prevalence estimates. FINDINGS: Of the 7.7 (95% uncertainty interval [UI], 7.4-8.1) million deaths among children and adolescents globally in 2013, 6.28 million occurred among younger children, 0.48 million among older children, and 0.97 million among adolescents. In 2013, the leading causes of death were lower respiratory tract infections among younger children (905.059 deaths; 95% UI, 810,304-998,125), diarrheal diseases among older children (38,325 deaths; 95% UI, 30,365-47,678), and road injuries among adolescents (115,186 deaths; 95% UI, 105,185-124,870). Iron deficiency anemia was the leading cause of years lived with disability among children and adolescents, affecting 619 (95% UI, 618-621) million in 2013. Large between-country variations exist in mortality from leading causes among children and adolescents. Countries with rapid declines in all-cause mortality between 1990 and 2013 also experienced large declines in most leading causes of death, whereas countries with the slowest declines had stagnant or increasing trends in the leading causes of death. In 2013, Nigeria had a 12% global share of deaths from lower respiratory tract infections and a 38% global share of deaths from malaria. India had 33% of the world's deaths from neonatal encephalopathy. Half of the world's diarrheal deaths among children and adolescents occurred in just 5 countries: India, Democratic Republic of the Congo, Pakistan, Nigeria, and Ethiopia. CONCLUSIONS AND RELEVANCE: Understanding the levels and trends of the leading causes of death and disability among children and adolescents is critical to guide investment and inform policies. Monitoring these trends over time is also key to understanding where interventions are having an impact. Proven interventions exist to prevent or treat the leading causes of unnecessary death and disability among children and adolescents. The findings presented here show that these are underused and give guidance to policy makers in countries where more attention is needed.

Addressing the burden of mental, neurological, and substance use disorders: key messages from Disease Control Priorities, 3rd edition.

The burden of mental, neurological, and substance use (MNS) disorders increased by 41% between 1990 and 2010 and now accounts for one in every 10 lost years of health globally. This sobering statistic does not take into account the substantial excess mortality associated with these disorders or the social and economic consequences of MNS disorders on affected persons, their caregivers, and society. A wide variety of effective interventions, including drugs, psychological treatments, and social interventions, can prevent and treat MNS disorders. At the population-level platform of service delivery, best practices include legislative measures to restrict access to means of self-harm or suicide and to reduce the availability of and demand for alcohol. At the community-level platform, best practices include life-skills training in schools to build social and emotional competencies. At the health-care-level platform, we identify three delivery channels. Two of these delivery channels are especially relevant from a public health perspective: self-management (eg, web-based psychological therapy for depression and anxiety disorders) and primary care and community outreach (eg, non-specialist health worker delivering psychological and pharmacological management of selected disorders). The third delivery channel, hospital care, which includes specialist services for MNS disorders and first-level hospitals providing other types of services (such as general medicine, HIV, or paediatric care), play an important part for a smaller proportion of cases with severe, refractory, or emergency presentations and for the integration of mental health care in other health-care channels, respectively. The costs of providing a significantly scaled up package of specified cost-effective interventions for prioritised MNS disorders in low-income and lower-middle-income countries is estimated at US$3-4 per head of population per year. Since a substantial proportion of MNS disorders run a chronic and disabling course and adversely affect household welfare, intervention costs should largely be met by government through increased resource allocation and financial protection measures (rather than leaving households to pay out-of-pocket). Moreover, a policy of moving towards universal public finance can also be expected to lead to a far more equitable allocation of public health resources across income groups. Despite this evidence, less than 1% of development assistance for health and government spending on health in low-income and middle-income countries is allocated to the care of people with these disorders. Achieving the health gains associated with prioritised interventions will require not just financial resources, but committed and sustained efforts to address a range of other barriers (such as paucity of human resources, weak governance, and stigma). Ultimately, the goal is to massively increase opportunities for people with MNS disorders to access services without the prospect of discrimination or impoverishment and with the hope of attaining optimal health and social outcomes.

Burden of mental and substance use disorders in Indigenous Australians and Oceania.

OBJECTIVE: Mental and substance use disorders are responsible for significant health loss across the globe. In this review, the burden of disease attributable to mental and substance use disorders in Indigenous Australians and Pacific Island countries was described and compared. METHODS: For Indigenous Australians, findings from the burden of disease and injury study by Begg and colleagues were summarised. These were then compared to the findings of the Global Burden of Disease Study 2010, which reported results for Oceania, a region consisting of Pacific Island countries. Results for mental and substance use disorder burden were described in terms of disability-adjusted life years, years lived with disability and years of life lost to due to premature mortality. RESULTS: Mental and substance use disorders were the leading cause of non-fatal burden (i.e. disability) in both Indigenous Australia and Oceania. Furthermore, in Oceania mental and substance use disorders are projected to cause more disability than all communicable diseases combined by 2050. CONCLUSION: Mental and substance use disorders contribute significantly to health loss for both Indigenous Australians and Pacific Island populations. These findings indicate a substantial need to prioritise these disorders in terms of policy, services and research.

Mental and substance use disorders in Sub-Saharan Africa: predictions of epidemiological changes and mental health workforce requirements for the next 40 years.

The world is undergoing a rapid health transition, with an ageing population and disease burden increasingly defined by disability. In Sub-Saharan Africa the next 40 years are predicted to see reduced mortality, signalling a surge in the impact of chronic diseases. We modelled these epidemiological changes and associated mental health workforce requirements. Years lived with a disability (YLD) predictions for mental and substance use disorders for each decade from 2010 to 2050 for four Sub-Saharan African regions were calculated using Global Burden of Disease 2010 study (GBD 2010) data and UN population forecasts. Predicted mental health workforce requirements for 2010 and 2050, by region and for selected countries, were modelled using GBD 2010 prevalence estimates and recommended packages of care and staffing ratios for low- and middle-income countries, and compared to current staffing from the WHO Mental Health Atlas. Significant population growth and ageing will result in an estimated 130% increase in the burden of mental and substance use disorders in Sub-Saharan Africa by 2050, to 45 million YLDs. As a result, the required mental health workforce will increase by 216,600 full time equivalent staff from 2010 to 2050, and far more compared to the existing workforce. The growth in mental and substance use disorders by 2050 is likely to significantly affect health and productivity in Sub-Saharan Africa. To reduce this burden, packages of care for key mental disorders should be provided through increasing the mental health workforce towards targets outlined in this paper. This requires a shift from current practice in most African countries, involving substantial investment in the training of primary care practitioners, supported by district based mental health specialist teams using a task sharing model that mobilises local community resources, with the expansion of inpatient psychiatric units based in district and regional general hospitals.

The contribution of major depression to the global burden of ischemic heart disease: a comparative risk assessment.

BACKGROUND: Cardiovascular disease and mental health both hold enormous public health importance, both ranking highly in results of the recent Global Burden of Disease Study 2010 (GBD 2010). For the first time, the GBD 2010 has systematically and quantitatively assessed major depression as an independent risk factor for the development of ischemic heart disease (IHD) using comparative risk assessment methodology. METHODS: A pooled relative risk (RR) was calculated from studies identified through a systematic review with strict inclusion criteria designed to provide evidence of independent risk factor status. Accepted case definitions of depression include diagnosis by a clinician or by non-clinician raters adhering to Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) classifications. We therefore refer to the exposure in this paper as major depression as opposed to the DSM-IV category of major depressive disorder (MDD). The population attributable fraction (PAF) was calculated using the pooled RR estimate. Attributable burden was calculated by multiplying the PAF by the underlying burden of IHD estimated as part of GBD 2010. RESULTS: The pooled relative risk of developing IHD in those with major depression was 1.56 (95% CI 1.30 to 1.87). Globally there were almost 4 million estimated IHD disability-adjusted life years (DALYs), which can be attributed to major depression in 2010; 3.5 million years of life lost and 250,000 years of life lived with a disability. These findings highlight a previously underestimated mortality component of the burden of major depression. As a proportion of overall IHD burden, 2.95% (95% CI 1.48 to 4.46%) of IHD DALYs were estimated to be attributable to MDD in 2010. Eastern Europe and North Africa/Middle East demonstrate the highest proportion with Asia Pacific, high income representing the lowest. CONCLUSIONS: The present work comprises the most robust systematic review of its kind to date. The key finding that major depression may be responsible for approximately 3% of global IHD DALYs warrants assessment for depression in patients at high risk of developing IHD or at risk of a repeat IHD event.

Burden of depressive disorders by country, sex, age, and year: findings from the global burden of disease study 2010.

BACKGROUND: Depressive disorders were a leading cause of burden in the Global Burden of Disease (GBD) 1990 and 2000 studies. Here, we analyze the burden of depressive disorders in GBD 2010 and present severity proportions, burden by country, region, age, sex, and year, as well as burden of depressive disorders as a risk factor for suicide and ischemic heart disease. METHODS AND FINDINGS: Burden was calculated for major depressive disorder (MDD) and dysthymia. A systematic review of epidemiological data was conducted. The data were pooled using a Bayesian meta-regression. Disability weights from population survey data quantified the severity of health loss from depressive disorders. These weights were used to calculate years lived with disability (YLDs) and disability adjusted life years (DALYs). Separate DALYs were estimated for suicide and ischemic heart disease attributable to depressive disorders. Depressive disorders were the second leading cause of YLDs in 2010. MDD accounted for 8.2% (5.9%-10.8%) of global YLDs and dysthymia for 1.4% (0.9%-2.0%). Depressive disorders were a leading cause of DALYs even though no mortality was attributed to them as the underlying cause. MDD accounted for 2.5% (1.9%-3.2%) of global DALYs and dysthymia for 0.5% (0.3%-0.6%). There was more regional variation in burden for MDD than for dysthymia; with higher estimates in females, and adults of working age. Whilst burden increased by 37.5% between 1990 and 2010, this was due to population growth and ageing. MDD explained 16 million suicide DALYs and almost 4 million ischemic heart disease DALYs. This attributable burden would increase the overall burden of depressive disorders from 3.0% (2.2%-3.8%) to 3.8% (3.0%-4.7%) of global DALYs. CONCLUSIONS: GBD 2010 identified depressive disorders as a leading cause of burden. MDD was also a contributor of burden allocated to suicide and ischemic heart disease. These findings emphasize the importance of including depressive disorders as a public-health priority and implementing cost-effective interventions to reduce its burden. Please see later in the article for the Editors' Summary.

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

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.

Global burden of disease attributable to illicit drug use and dependence: findings from the Global Burden of Disease Study 2010.

BACKGROUND: No systematic attempts have been made to estimate the global and regional prevalence of amphetamine, cannabis, cocaine, and opioid dependence, and quantify their burden. We aimed to assess the prevalence and burden of drug dependence, as measured in years of life lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life years (DALYs). METHODS: We conducted systematic reviews of the epidemiology of drug dependence, and analysed results with Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) Bayesian meta-regression technique (DisMod-MR) to estimate population-level prevalence of dependence and use. GBD 2010 calculated new disability weights by use of representative community surveys and an internet-based survey. We combined estimates of dependence with disability weights to calculate prevalent YLDs, YLLs, and DALYs, and estimated YLDs, YLLs, and DALYs attributable to drug use as a risk factor for other health outcomes. FINDINGS: Illicit drug dependence directly accounted for 20·0 million DALYs (95% UI 15·3-25·4 million) in 2010, accounting for 0·8% (0·6-1·0) of global all-cause DALYs. Worldwide, more people were dependent on opioids and amphetamines than other drugs. Opioid dependence was the largest contributor to the direct burden of DALYs (9·2 million, 95% UI 7·1-11·4). The proportion of all-cause DALYs attributed to drug dependence was 20 times higher in some regions than others, with an increased proportion of burden in countries with the highest incomes. Injecting drug use as a risk factor for HIV accounted for 2·1 million DALYs (95% UI 1·1-3·6 million) and as a risk factor for hepatitis C accounted for 502,000 DALYs (286,000-891,000). Suicide as a risk of amphetamine dependence accounted for 854,000 DALYs (291,000-1,791,000), as a risk of opioid dependence for 671,000 DALYs (329,000-1,730,000), and as a risk of cocaine dependence for 324,000 DALYs (109,000-682,000). Countries with the highest rate of burden (>650 DALYs per 100,000 population) included the USA, UK, Russia, and Australia. INTERPRETATION: Illicit drug use is an important contributor to the global burden of disease. Efficient strategies to reduce disease burden of opioid dependence and injecting drug use, such as delivery of opioid substitution treatment and needle and syringe programmes, are needed to reduce this burden at a population scale. FUNDING: Australian National Health and Medical Research Council, Australian Government Department of Health and Ageing, Bill & Melinda Gates Foundation.

The epidemiological modelling of major depressive disorder: application for the Global Burden of Disease Study 2010.

BACKGROUND: Although the detrimental impact of major depressive disorder (MDD) at the individual level has been described, its global epidemiology remains unclear given limitations in the data. Here we present the modelled epidemiological profile of MDD dealing with heterogeneity in the data, enforcing internal consistency between epidemiological parameters and making estimates for world regions with no empirical data. These estimates were used to quantify the burden of MDD for the Global Burden of Disease Study 2010 (GBD 2010). METHOD: Analyses drew on data from our existing literature review of the epidemiology of MDD. DisMod-MR, the latest version of the generic disease modelling system redesigned as a Bayesian meta-regression tool, derived prevalence by age, year and sex for 21 regions. Prior epidemiological knowledge, study- and country-level covariates adjusted sub-optimal raw data. RESULTS: There were over 298 million cases of MDD globally at any point in time in 2010, with the highest proportion of cases occurring between 25 and 34 years. Global point prevalence was very similar across time (4.4% (95% uncertainty: 4.2-4.7%) in 1990, 4.4% (4.1-4.7%) in 2005 and 2010), but higher in females (5.5% (5.0-6.0%) compared to males (3.2% (3.0-3.6%) in 2010. Regions in conflict had higher prevalence than those with no conflict. The annual incidence of an episode of MDD followed a similar age and regional pattern to prevalence but was about one and a half times higher, consistent with an average duration of 37.7 weeks. CONCLUSION: We were able to integrate available data, including those from high quality surveys and sub-optimal studies, into a model adjusting for known methodological sources of heterogeneity. We were also able to estimate the epidemiology of MDD in regions with no available data. This informed GBD 2010 and the public health field, with a clearer understanding of the global distribution of MDD.

The epidemiological modelling of dysthymia: application for the Global Burden of Disease Study 2010.

BACKGROUND: In order to capture the differences in burden between the subtypes of depression, the Global Burden of Disease 2010 Study for the first time estimated the burden of dysthymia and major depressive disorder separately from the previously used umbrella term 'unipolar depression'. A global summary of epidemiological parameters are necessary inputs in burden of disease calculations for 21 world regions, males and females and for the year 1990, 2005 and 2010. This paper reports findings from a systematic review of global epidemiological data and the subsequent development of an internally consistent epidemiological model of dysthymia. METHODS: A systematic search was conducted to identify data sources for the prevalence, incidence, remission and excess-mortality of dysthymia using Medline, PsycINFO and EMBASE electronic databases and grey literature. DisMod-MR, a Bayesian meta-regression tool, was used to check the epidemiological parameters for internal consistency and to predict estimates for world regions with no or few data. RESULTS: The systematic review identified 38 studies meeting inclusion criteria which provided 147 data points for 30 countries in 13 of 21 world regions. Prevalence increases in the early ages, peaking at around 50 years. Females have higher prevalence of dysthymia than males. Global pooled prevalence remained constant across time points at 1.55% (95%CI 1.50-1.60). There was very little regional variation in prevalence estimates. LIMITATIONS: There were eight GBD world regions for which we found no data for which DisMod-MR had to impute estimates. CONCLUSION: The addition of internally consistent epidemiological estimates by world region, age, sex and year for dysthymia contributed to a more comprehensive estimate of mental health burden in GBD 2010.