Identifying characteristics and practices of multidisciplinary team reviews for patients with severe mental illness: a systematic review.

OBJECTIVES: Multidisciplinary teams in mental health receive limited guidance, leading to inconsistent practices. We undertook a systematic review of the characteristics and practices of multidisciplinary team reviews for patients with severe mental illness or in relevant mental health service settings. METHODS: Sources published since 2000 were located via academic database and web searches. Results were synthesised narratively. RESULTS: A total of 14 sources were analysed. Important characteristics and practices identified included routine monitoring and evaluation, good communication, equality between team members, and clear documentation practices. Success factors included defined leadership and clear team goals. Four sources described considerations for patients with complex clinical needs, including allocating sufficient time for discussion, maintaining connections with community providers, and ensuring culturally sensitive practices. CONCLUSIONS: No single best practice model was found, due to variations in team caseload, casemix, and resourcing levels. However, key ingredients for success were proposed. Sources were mostly descriptive; there remains a lack of evidence-based guidance regarding multidisciplinary team review characteristics and practices.

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.

Assessing service use for mental health by Indigenous populations in Australia, Canada, New Zealand and the United States of America: a rapid review of population surveys.

BACKGROUND: Indigenous people in Australia, Canada, New Zealand and the United States of America experience disproportionately poor mental health compared to their non-Indigenous counterparts. To optimally allocate resources, health planners require information about the services Indigenous people use for mental health, their unmet treatment needs and the barriers to care. We reviewed population surveys of Indigenous people to determine whether the information needed to guide service development is being collected. METHODS: We sought national- or state-level epidemiological surveys of Indigenous populations conducted in each of the four selected countries since 1990 that asked about service use for mental health. Surveys were identified from literature reviews and web searches. We developed a framework for categorising the content of each survey. Using this framework, we compared the service use content of the surveys of Indigenous people to each other and to general population mental health surveys. We focused on identifying gaps in information coverage and topics that may require Indigenous-specific questions or response options. RESULTS: Nine surveys met our inclusion criteria. More than half of these included questions about health professionals consulted, barriers to care, perceived need for care, medications taken, number, duration, location and payment of health professional visits or use of support services or self-management. Less than half included questions about interventions received, hospital admissions or treatment dropout. Indigenous-specific content was most common in questions regarding use of support services or self-management, types of health professionals consulted, barriers to care and interventions received. CONCLUSIONS: Epidemiological surveys measuring service use for mental health among Indigenous populations have been less comprehensive and less standardised than surveys of the general population, despite having assessed similar content. To better understand the gaps in mental health service systems for Indigenous people, systematically-collected subjective and objective indicators of the quality of care being delivered are needed.

Reducing excess mortality due to chronic disease in people with severe mental illness: meta-review of health interventions.

BACKGROUND: People with severe mental illness (SMI) have high rates of chronic disease and premature death. AIMS: To explore the strength of evidence for interventions to reduce risk of mortality in people with SMI. METHOD: In a meta-review of 16 systematic reviews of controlled studies, mortality was the primary outcome (8 reviews). Physiological health measures (body mass index, weight, glucose levels, lipid profiles and blood pressure) were secondary outcomes (14 reviews). RESULTS: Antipsychotic and antidepressant medications had some protective effect on mortality, subject to treatment adherence. Integrative community care programmes may reduce physical morbidity and excess deaths, but the effective ingredients are unknown. Interventions to improve unhealthy lifestyles and risky behaviours can improve risk factor profiles, but longer follow-up is needed. Preventive interventions and improved medical care for comorbid chronic disease may reduce excess mortality, but data are lacking. CONCLUSIONS: Improved adherence to pharmacological and physical health management guidelines is indicated.

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.

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.

Challenging the myth of an "epidemic" of common mental disorders: trends in the global prevalence of anxiety and depression between 1990 and 2010.

BACKGROUND: Anxiety disorders and major depressive disorder (MDD) are common and disabling mental disorders. This paper aims to test the hypothesis that common mental disorders have become more prevalent over the past two decades. METHODS: We conducted a systematic review of prevalence, remission, duration, and excess mortality studies for anxiety disorders and MDD and then used a Bayesian meta-regression approach to estimate point prevalence for 1990, 2005, and 2010. We also conducted a post-hoc search for studies that used the General Health Questionnaire (GHQ) as a measure of psychological distress and tested for trends to present a qualitative comparison of study findings RESULTS: This study found no evidence for an increased prevalence of anxiety disorders or MDD. While the crude number of cases increased by 36%, this was explained by population growth and changing age structures. Point prevalence of anxiety disorders was estimated at 3.8% (3.6-4.1%) in 1990 and 4.0% (3.7-4.2%) in 2010. The prevalence of MDD was unchanged at 4.4% in 1990 (4.2-4.7%) and 2010 (4.1-4.7%). However, 8 of the 11 GHQ studies found a significant increase in psychological distress over time. CONCLUSIONS: The perceived "epidemic" of common mental disorders is most likely explained by the increasing numbers of affected patients driven by increasing population sizes. Additional factors that may explain this perception include the higher rates of psychological distress as measured using symptom checklists, greater public awareness, and the use of terms such as anxiety and depression in a context where they do not represent clinical disorders.

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.

Health states for schizophrenia and bipolar disorder within the Global Burden of Disease 2010 Study.

A comprehensive revision of the Global Burden of Disease (GBD) study is expected to be completed in 2012. This study utilizes a broad range of improved methods for assessing burden, including closer attention to empirically derived estimates of disability. The aim of this paper is to describe how GBD health states were derived for schizophrenia and bipolar disorder. These will be used in deriving health state-specific disability estimates. A literature review was first conducted to settle on a parsimonious set of health states for schizophrenia and bipolar disorder. A second review was conducted to investigate the proportion of schizophrenia and bipolar disorder cases experiencing these health states. These were pooled using a quality-effects model to estimate the overall proportion of cases in each state. The two schizophrenia health states were acute (predominantly positive symptoms) and residual (predominantly negative symptoms). The three bipolar disorder health states were depressive, manic, and residual. Based on estimates from six studies, 63% (38%-82%) of schizophrenia cases were in an acute state and 37% (18%-62%) were in a residual state. Another six studies were identified from which 23% (10%-39%) of bipolar disorder cases were in a manic state, 27% (11%-47%) were in a depressive state, and 50% (30%-70%) were in a residual state. This literature review revealed salient gaps in the literature that need to be addressed in future research. The pooled estimates are indicative only and more data are required to generate more definitive estimates. That said, rather than deriving burden estimates that fail to capture the changes in disability within schizophrenia and bipolar disorder, the derived proportions and their wide uncertainty intervals will be used in deriving disability estimates.

Should global burden of disease estimates include depression as a risk factor for coronary heart disease?

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.

Mental disorders as risk factors: assessing the evidence for the Global Burden of Disease Study.

BACKGROUND: Mental disorders are associated with a considerable burden of disease as well as being risk factors for other health outcomes. The new Global Burden of Disease (GBD) Study will make estimates for both the disability and mortality directly associated with mental disorders, as well as the burden attributable to other health outcomes. Herein we discuss the process by which health outcomes in which mental disorders are risk factors are selected for inclusion in the GBD Study. We make suggestions for future research to strengthen the body of evidence for mental disorders as risk factors. METHODS: We identified a list of potential associations between mental disorders and subsequent health outcomes based on a review of the literature and consultation with mental health experts. A two-stage filter was applied to identify mental disorders and health outcomes that meet the criteria for inclusion in the GBD Study. Major limitations in the current literature are discussed and illustrated with examples identified during our review. RESULTS AND DISCUSSION: Only two associations are included in the new GBD Study. These associations are the increased risk of ischemic heart disease with major depression and mental disorders as a risk factor for suicide. There is evidence that mental disorders are independent risk factors for cardiovascular disease (CVD), type 2 diabetes and injuries. However, these associations were unable to be included because of insufficient data. The most common reasons for exclusion were inconsistent identification of 'cases', uncertain validity of health outcomes, lack of generalizability, insufficient control for confounding factors and lack of evidence for temporality. CONCLUSIONS: CVD, type 2 diabetes and injury are important public health policy areas. Prospective community studies of outcomes in patients with mental disorders are required, and their design must address a range of confounding factors.

The Queensland Study of Melanoma: environmental and genetic associations (Q-MEGA); study design, baseline characteristics, and repeatability of phenotype and sun exposure measures.

Cutaneous malignant melanoma (CMM) is a major health issue in Queensland, Australia, which has the world's highest incidence. Recent molecular and epidemiologic studies suggest that CMM arises through multiple etiological pathways involving gene-environment interactions. Understanding the potential mechanisms leading to CMM requires larger studies than those previously conducted. This article describes the design and baseline characteristics of Q-MEGA, the Queensland Study of Melanoma: Environmental and Genetic Associations, which followed up 4 population-based samples of CMM patients in Queensland, including children, adolescents, men aged over 50, and a large sample of adult cases and their families, including twins. Q-MEGA aims to investigate the roles of genetic and environmental factors, and their interaction, in the etiology of melanoma. Three thousand, four hundred and seventy-one participants took part in the follow-up study and were administered a computer-assisted telephone interview in 2002-2005. Updated data on environmental and phenotypic risk factors, and 2777 blood samples were collected from interviewed participants as well as a subset of relatives. This study provides a large and well-described population-based sample of CMM cases with follow-up data. Characteristics of the cases and repeatability of sun exposure and phenotype measures between the baseline and the follow-up surveys, from 6 to 17 years later, are also described.

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.

The global epidemiology and burden of psychostimulant dependence: findings from the Global Burden of Disease Study 2010.

AIMS: To estimate the global prevalence of cocaine and amphetamine dependence and the burden of disease attributable to these disorders. METHODS: An epidemiological model was developed using DisMod-MR, a Bayesian meta-regression tool, using epidemiological data (prevalence, incidence, remission and mortality) sourced from a multi-stage systematic review of data. Age, sex and region-specific prevalence was estimated for and multiplied by comorbidity-adjusted disability weightings to estimate years of life lost to disability (YLDs) from these disorders. Years of life lost (YLL) were estimated from cross-national vital registry data. Disability-adjusted life years (DALYs) were estimated by summing YLDs and YLLs in 21 regions, by sex and age, in 1990 and 2010. RESULTS: In 2010, there were an estimated 24.1 million psychostimulant dependent people: 6.9 million cocaine and 17.2 million amphetamines, equating to a point prevalence of 0.10% (0.09-0.11%) for cocaine, and 0.25% (0.22-0.28%) for amphetamines. There were 37.6 amphetamine dependence DALYs (21.3-59.3) per 100,000 population in 2010 and 15.9 per 100,000 (9.3-25.0) cocaine dependence DALYs. There were clear differences between amphetamines and cocaine in the geographic distribution of crude DALYs. Over half of amphetamine dependence DALYs were in Asian regions (52%), whereas almost half of cocaine dependence DALYs were in the Americas (44%, with 23% in North America High Income). CONCLUSION: Dependence upon psychostimulants is a substantial contributor to global disease burden; the contribution of cocaine and amphetamines to this burden varies dramatically by geographic region. There is a need to scale up evidence-based interventions to reduce this burden.

The regional distribution of anxiety disorders: implications for the Global Burden of Disease Study, 2010.

Anxiety disorders are increasingly acknowledged as a global health issue however an accurate picture of prevalence across populations is lacking. Empirical data are incomplete and inconsistent so alternate means of estimating prevalence are required to inform estimates for the new Global Burden of Disease Study 2010. We used a Bayesian meta-regression approach which included empirical epidemiological data, expert prior information, study covariates and population characteristics. Reported are global and regional point prevalence for anxiety disorders in 2010. Point prevalence of anxiety disorders differed by up to three-fold across world regions, ranging between 2.1% (1.8-2.5%) in East Asia and 6.1% (5.1-7.4%) in North Africa/Middle East. Anxiety was more common in Latin America; high income regions; and regions with a history of recent conflict. There was considerable uncertainty around estimates, particularly for regions where no data were available. Future research is required to examine whether variations in regional distributions of anxiety disorders are substantive differences or an artefact of cultural or methodological differences. This is a particular imperative where anxiety is consistently reported to be less common, and where it appears to be elevated, but uncertainty prevents the reporting of conclusive estimates.

The burden attributable to mental and substance use disorders as risk factors for suicide: findings from the Global Burden of Disease Study 2010.

BACKGROUND: The Global Burden of Disease Study 2010 (GBD 2010) identified mental and substance use disorders as the 5th leading contributor of burden in 2010, measured by disability adjusted life years (DALYs). This estimate was incomplete as it excluded burden resulting from the increased risk of suicide captured elsewhere in GBD 2010's mutually exclusive list of diseases and injuries. Here, we estimate suicide DALYs attributable to mental and substance use disorders. METHODS: Relative-risk estimates of suicide due to mental and substance use disorders and the global prevalence of each disorder were used to estimate population attributable fractions. These were adjusted for global differences in the proportion of suicide due to mental and substance use disorders compared to other causes then multiplied by suicide DALYs reported in GBD 2010 to estimate attributable DALYs (with 95% uncertainty). RESULTS: Mental and substance use disorders were responsible for 22.5 million (14.8-29.8 million) of the 36.2 million (26.5-44.3 million) DALYs allocated to suicide in 2010. Depression was responsible for the largest proportion of suicide DALYs (46.1% (28.0%-60.8%)) and anorexia nervosa the lowest (0.2% (0.02%-0.5%)). DALYs occurred throughout the lifespan, with the largest proportion found in Eastern Europe and Asia, and males aged 20-30 years. The inclusion of attributable suicide DALYs would have increased the overall burden of mental and substance use disorders (assigned to them in GBD 2010 as a direct cause) from 7.4% (6.2%-8.6%) to 8.3% (7.1%-9.6%) of global DALYs, and would have changed the global ranking from 5th to 3rd leading cause of burden. CONCLUSIONS: Capturing the suicide burden attributable to mental and substance use disorders allows for more accurate estimates of burden. More consideration needs to be given to interventions targeted to populations with, or at risk for, mental and substance use disorders as an effective strategy for suicide prevention.

How did we arrive at burden of disease estimates for mental and illicit drug use disorders in the Global Burden of Disease Study 2010?

PURPOSE OF REVIEW: The Global Burden of Disease study 2010 (GBD 2010) estimated regional and global burden of 291 diseases and 67 risk factors. Here, we provide an overview of the methodological approach taken to this work, as well as the challenges and limitations encountered in deriving the burden of mental and drug use disorders. RECENT FINDINGS: GBD 2010 estimated the burden of 11 mental disorders and four drug use disorders for 21 regions. This involved a systematic literature search for epidemiological data; setting lay case definitions; synthesizing available epidemiological data into an internally consistent disease model; and quantifying the associated disability and health outcomes, to derive region, sex, year and age-specific burden estimates. Notable challenges included the difficulty in deriving culturally comparable case definitions for mental and drug use disorders, the paucity of epidemiological data and the difficulty in capturing disability associated with mental and drug use disorders. SUMMARY: GBD 2010 findings demonstrated the major public health importance of mental and drug use disorders. The methodology used to estimate burden was more sophisticated than previous GBD studies, with some restrictions required in order to achieve defensible numerical measures of burden for mental and drug use disorders.

Global epidemiology of mental disorders: what are we missing?

BACKGROUND: Population-based studies provide the understanding of health-need required for effective public health policy and service-planning. Mental disorders are an important but, until recently, neglected agenda in global health. This paper reviews the coverage and limitations in global epidemiological data for mental disorders and suggests strategies to strengthen the data. METHODS: Systematic reviews were conducted for population-based epidemiological studies in mental disorders to inform new estimates for the global burden of disease study. Estimates of population coverage were calculated, adjusted for study parameters (age, gender and sampling frames) to quantify regional coverage. RESULTS: Of the 77,000 data sources identified, fewer than 1% could be used for deriving national estimates of prevalence, incidence, remission, and mortality in mental disorders. The two major limitations were (1) highly variable regional coverage, and (2) important methodological issues that prevented synthesis across studies, including the use of varying case definitions, the selection of samples not allowing generalization, lack of standardized indicators, and incomplete reporting. North America and Australasia had the most complete prevalence data for mental disorders while coverage was highly variable across Europe, Latin America, and Asia Pacific, and poor in other regions of Asia and Africa. Nationally-representative data for incidence, remission, and mortality were sparse across most of the world. DISCUSSION: Recent calls to action for global mental health were predicated on the high prevalence and disability of mental disorders. However, the global picture of disorders is inadequate for planning. Global data coverage is not commensurate with other important health problems, and for most of the world's population, mental disorders are invisible and remain a low priority.

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

BACKGROUND: The multiple factors likely to influence estimates of the prevalence of bipolar spectrum disorders (BSD) make it difficult to determine its actual prevalence. A systematic review was undertaken to explore the availability and quality of epidemiological data for BSD. This will inform the Global Burden of Disease 2010 study. METHODS: Electronic databases searched were Medline, PsycInfo and EMBASE using search terms generated in consultation with a research librarian. Reference lists were searched and experts contacted to obtain articles not identified through the database search. Prevalence data pertaining to point, 6 month or 12 month prevalence of BSD were sought. RESULTS: The mean pooled prevalence was 0.741% (point) and 0.843% (6/12 months). The study region, response rate and diagnostic tool had a significant impact on prevalence estimates but there were no significant differences in prevalence across prevalence types, gender, sample coverage, economic status and bipolar subtype. Little or no prevalence data was apparent for many regions of the world. Also, the entire bipolar spectrum was rarely assessed. LIMITATIONS: Although stringent quality assurance methodology was used, controlling for all sources of variability around the pooled prevalence was not possible. CONCLUSIONS: This systematic review has made significant contributions to the epidemiological profile of BSD. Prevalence estimates will be used to generate estimates of burden for BSD in the global burden of disease 2010 study.