Fiona J. Charlson

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.

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

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

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.

The global epidemiology and burden of opioid dependence: results from the global burden of disease 2010 study

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.

Excess mortality in persons with severe mental disorders: a multilevel intervention framework and priorities for clinical practice, policy and research agendas

AIMS To estimate the prevalence and burden of disease attributable to opioid dependence globally, regionally and at country level. METHODS Multiple search strategies: (i) peer-reviewed literature searches; (ii) systematic searches of online databases; (iii) internet searches; (iv) consultation and feedback from experts. Culling and data extraction followed protocols. DisMod-MR, the latest version of the generic disease modelling system, a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. Disability weight for opioid dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs). Opioid dependence premature mortality was computed as years of life lost (YLLs) and summed with YLDs to calculate disability-adjusted life years (DALYs). RESULTS There were 15.5 million opioid-dependent people globally in 2010 [0.22%, 95% uncertainty interval (UI) = 0.20-0.25%]. Age-standardized prevalence was higher in males (0.30%, 95% UI = 0.27-0.35%) than females (0.14%, 95% UI = 0.12-0.16%), and peaked at 25-29 years. Prevalence was higher than the global pooled prevalence in Australasia (0.46%, 95% UI = 0.41-0.53%), western Europe (0.35%, 95% UI = 0.32-0.39) and North America (0.30%, 95% UI = 0.25-0.36). Opioid dependence was estimated to account for 9.2 million DALYs globally (0.37% of global DALYs) in 2010, a 73% increase on DALYs estimated in 1990. Regions with the highest opioid dependence DALY rates were North America (292.1 per 100,000), eastern Europe (288.4 per 100,000), Australasia (278.6 per 100,000) and southern sub-Saharan Africa (263.5 per 100,000). The contribution of YLLs to opioid dependence burden was particularly high in North America, eastern Europe and southern sub-Saharan Africa. CONCLUSION Opioid dependence is a substantial contributor to the global disease burden; its contribution to premature mortality (relative to prevalence) varies geographically, with North America, eastern Europe and southern sub-Saharan Africa most strongly affected.

Should Global Burden of Disease Estimates Include Depression as a Risk Factor for Coronary Heart Disease

Excess mortality in persons with severe mental disorders (SMD) is a major public health challenge that warrants action. The number and scope of truly tested interventions in this area remain limited, and strategies for implementation and scaling up of programmes with a strong evidence base are scarce. Furthermore, the majority of available interventions focus on a single or an otherwise limited number of risk factors. Here we present a multilevel model highlighting risk factors for excess mortality in persons with SMD at the individual, health system and socio‐environmental levels. Informed by that model, we describe a comprehensive framework that may be useful for designing, implementing and evaluating interventions and programmes to reduce excess mortality in persons with SMD. This framework includes individual‐focused, health system‐focused, and community level and policy‐focused interventions. Incorporating lessons learned from the multilevel model of risk and the comprehensive intervention framework, we identify priorities for clinical practice, policy and research agendas.

Excess Mortality from Mental, Neurological, and Substance Use Disorders in the Global Burden of Disease Study 2010

The 2010 Global Burden of Disease Study estimates the premature mortality and disability of all major diseases and injuries. In addition it aims to quantify the risk that diseases and other factors play in the aetiology of disease and injuries. Mental disorders and coronary heart disease are both significant public health issues due to their high prevalence and considerable contribution to global disease burden. For the first time the Global Burden of Disease Study will aim to assess mental disorders as risk factors for coronary heart disease. We show here that current evidence satisfies established criteria for considering depression as an independent risk factor in development of coronary heart disease. A dose response relationship appears to exist and plausible biological pathways have been proposed. However, a number of challenges exist when conducting a rigorous assessment of the literature including heterogeneity issues, definition and measurement of depression and coronary heart disease, publication bias and residual confounding. Therefore, despite some limitations in the available data, it is now appropriate to consider major depression as a risk factor for coronary heart disease in the new Global Burden of Disease Study.

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

Aims. Mortality-associated burden of disease estimates from the Global Burden of Disease 2010 (GBD 2010) may erroneously lead to the interpretation that premature death in people with mental, neurological and substance use disorders (MNSDs) is inconsequential when evidence shows that people with MNSDs experience a significant reduction in life expectancy. We explore differences between cause-specific and excess mortality of MNSDs estimated by GBD 2010. Methods. GBD 2010 cause-specific death estimates were produced using the International Classification of Diseases death-coding system. Excess mortality (all-cause) was estimated using natural history models. Additional mortality attributed to MNSDs as underlying causes but not captured through GBD 2010 methodology is quantified in the comparative risk assessments. Results. In GBD 2010, MNSDs were estimated to be directly responsible for 840 000 deaths compared with more than 13 million excess deaths using natural history models. Conclusions. Numbers of excess deaths and attributable deaths clearly demonstrate the high degree of mortality associated with these disorders. There is substantial evidence pointing to potential causal pathways for this premature mortality with evidence-based interventions available to address this mortality. The life expectancy gap between persons with MNSDs and the general population is high and should be a focus for health systems reform.

ECT efficacy and treatment course: a systematic review and meta-analysis of twice vs thrice weekly schedules.

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.