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 5^th 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 5^th to 3^rd 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.     

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     

The Global Epidemiology and Contribution of Cannabis Use and Dependence to the Global Burden of Disease: Results from the GBD 2010 Study

AimsEstimate the prevalence of cannabis dependence and its contribution to the global burden of disease.MethodsSystematic reviews of epidemiological data on cannabis dependence (1990-2008) were conducted in line with PRISMA and meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Culling and data extraction followed protocols, with cross-checking and consistency checks. DisMod-MR, the latest version of generic disease modelling system, redesigned as a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. The disability weight associated with cannabis dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs) and disability-adjusted life years (DALYs). YLDs and DALYs attributed to regular cannabis use as a risk factor for schizophrenia were also estimated.ResultsThere were an estimated 13.1 million cannabis dependent people globally in 2010 (point prevalence0.19% (95% uncertainty: 0.17-0.21%)). Prevalence peaked between 20-24 yrs, was higher in males (0.23% (0.2-0.27%)) than females (0.14% (0.12-0.16%)) and in high income regions. Cannabis dependence accounted for 2 million DALYs globally (0.08%; 0.05-0.12%) in 2010; a 22% increase in crude DALYs since 1990 largely due to population growth. Countries with statistically higher age-standardised DALY rates included the United States, Canada, Australia, New Zealand and Western European countries such as the United Kingdom; those with lower DALY rates were from Sub-Saharan Africa-West and Latin America. Regular cannabis use as a risk factor for schizophrenia accounted for an estimated 7,000 DALYs globally.ConclusionCannabis dependence is a disorder primarily experienced by young adults, especially in higher income countries. It has not been shown to increase mortality as opioid and other forms of illicit drug dependence do. Our estimates suggest that cannabis use as a risk factor for schizophrenia is not a major contributor to population-level disease burden.     

Burden of Infectious Diseases,Substance Use Disorders,and Mental Illness among Ukrainian Prisoners Transitioning to the Community

Background

The epidemics of incarceration, substance use disorders (SUDs), and infectious diseases are inextricably intertwined, especially in the Former Soviet Union (FSU). Few objective data documenting this relationship regionally are available. We therefore conducted a comprehensive, representative country-wide prison health survey in Ukraine, where one of the world’s most volatile HIV epidemics persists, in order to address HIV prevention and treatment needs.

Methods

A nation-wide, multi-site randomly sampled biobehavioral health survey was conducted in four Ukrainian regions in 13 prisons among individuals being released within six months. After consent, participants underwent standardized health assessment surveys and serological testing for HIV, viral hepatitis, and syphilis.

Results

Of the 402 participants (mean age = 31.9 years), 20.1% were female. Prevalence of HIV, HCV, HBV, and syphilis was 19.4% (95% CI = 15.5%–23.3%), 60.2% (95% CI = 55.1%–65.4%), 5.2% (95% CI = 3.3%–7.2%), and 10% (95% CI = 7.4%–13.2%), respectively, with regional differences observed; HIV prevalence in the south was 28.6%. Among the 78 HIV-infected inmates, 50.7% were unaware of their HIV status and 44 (56.4%) had CD4<350 cells/mL, of which only five (11%) antiretroviral-eligible inmates were receiving it. Nearly half of the participants (48.7%) reported pre-incarcertion drug injection, primarily of opioids, yet multiple substance use (31.6%) and alcohol use disorders (56.6%) were common and 40.3% met screening criteria for depression.

Conclusions

This is the only such representative health study of prisoners in the FSU. This study has important implications for regional prevention and treatment because, unlike elsewhere, there is no recent evidence for reduction in HIV incidence and mortality in the region. The prevalence of infectious diseases and SUDs is high among this sample of prisoners transitioning to the community. It is critical to address pre- and post-release prevention and treatment needs with the development of linkage programs for the continuity of care in the community after release.     

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.     

Substance Use Disorders and Adoption: Findings from a National Sample

Background

Prior research has shown that adoptees have a higher rate of substance use disorders (SUDs) than nonadoptees. But these findings have not been verified with a population-based sample of adult adoptees in the United States. Also, no previous adoption study has measured the prevalence of each specific substance use disorder (SUD). We aimed to compare lifetime prevalence rates and odds ratios of SUDs in adopted and nonadopted adults.

Methods and Findings

The data come from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The main outcome measure was the prevalence of lifetime SUDs in adopted (n = 378) and nonadopted adults (n = 42503). Adoptees and nonadoptees were compared to estimate the odds of lifetime SUDs using logistic regression analysis. Adoptees had higher prevalence rates of lifetime SUDs than nonadoptees. Overall, adoptees had a 1.87-fold increase (adjusted odds ratio [AOR] 1.87, 95% CI 1.51–2.31) in the odds of any lifetime SUD compared to nonadoptees. For each SUD, adoptees had higher odds for alcohol abuse/dependence (AOR 1.84), nicotine dependence (AOR 1.78), cannabis abuse/dependence (AOR 1.77), cocaine abuse/dependence (AOR 2.54), amphetamine abuse/dependence (AOR 3.14), hallucinogen abuse/dependence (AOR 2.85), opioid abuse/dependence (AOR 2.21), and other drug abuse/dependence (AOR 2.87) compared to nonadoptees. This study also identified two adoption-specific risk factors (Hispanic, never married) associated with any lifetime SUD.

Conclusions

This study demonstrated an increased risk of lifetime SUDs in adopted adults. The findings can be useful for clinicians and policy makers to provide education, prevention, and support for adoptees and their families.     

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.     

Enterovirus 71-Induced Neurological Disorders in Young Gerbils,Meriones unguiculatus: Development and Application of a Neurological Disease Model

A reliable disease model mimicking Enterovirus 71 (EV71) infection in humans is essential for understanding pathogenesis and for developing a safe and effective vaccine. Commonly used rodent models including mouse or rat models are not suitable for vaccine evaluation because the rodents are resistant to EV71 infection after they reach the age of 6 days. In this study, 21-day-old gerbils inoculated intraperitoneally (IP) with a non mouse-adapted EV71 strain developed neurological lesion-related signs including hind limb paralysis, slowness, ataxia and lethargy similar to those of central nervous system (CNS) infection of EV71 in humans. The infected gerbils eventually died of the neurological lesions and EV71 could be isolated from lung, liver, spleen, kidney, heart, spinal cord, brain cortex, brainstem and skeletal muscle. Significantly high virus replication was detected in spinal cord, brainstem and skeletal muscle by cellular analysis, real-time quantitative PCR (RT-PCR) and immunohistochemical staining. Histopathologic changes such as neuronal degeneration, neuronal loss and neuronophagia were observed in spinal cord, brain cortex, brainstem, and skeletal muscle along with necrotizing myositis and splenic atrophy. Gerbils that received two doses of inactive whole-virus vaccine showed no EV71-specific symptoms after challenged with EV71. In contrast, gerbils that received mock vaccination died of EV71-induced neuropathology after challenged with EV71. The result indicates that gerbils can serve as a reliable disease model for evaluating safety and efficacy of EV71 vaccine.     

World Health Organization Global Estimates and Regional Comparisons of the Burden of Foodborne Disease in 2010

Illness and death from diseases caused by contaminated food are a constant threat to public health and a significant impediment to socio-economic development worldwide. To measure the global and regional burden of foodborne disease (FBD), the World Health Organization (WHO) established the Foodborne Disease Burden Epidemiology Reference Group (FERG), which here reports their first estimates of the incidence, mortality, and disease burden due to 31 foodborne hazards. We find that the global burden of FBD is comparable to those of the major infectious diseases, HIV/AIDS, malaria and tuberculosis. The most frequent causes of foodborne illness were diarrheal disease agents, particularly norovirus and Campylobacter spp. Diarrheal disease agents, especially non-typhoidal Salmonella enterica, were also responsible for the majority of deaths due to FBD. Other major causes of FBD deaths were Salmonella Typhi, Taenia solium and hepatitis A virus. The global burden of FBD caused by the 31 hazards in 2010 was 33 million Disability Adjusted Life Years (DALYs); children under five years old bore 40% of this burden. The 14 subregions, defined on the basis of child and adult mortality, had considerably different burdens of FBD, with the greatest falling on the subregions in Africa, followed by the subregions in South-East Asia and the Eastern Mediterranean D subregion. Some hazards, such as non-typhoidal S. enterica, were important causes of FBD in all regions of the world, whereas others, such as certain parasitic helminths, were highly localised. Thus, the burden of FBD is borne particularly by children under five years old–although they represent only 9% of the global population–and people living in low-income regions of the world. These estimates are conservative, i.e., underestimates rather than overestimates; further studies are needed to address the data gaps and limitations of the study. Nevertheless, all stakeholders can contribute to improvements in food safety throughout the food chain by incorporating these estimates into policy development at national and international levels.

Summary Points

• Thirty-one foodborne hazards caused 600 (95% uncertainty interval [UI] 420–960) million foodborne illnesses and 420,000 (95% UI 310,000–600,000) deaths in 2010.
• The global burden of FBD caused by the 31 hazards studied was 33 (95% UI 25–46) million DALYs in 2010.
• The most frequent causes of foodborne illness were diarrheal disease agents; particularly norovirus and Campylobacter spp.
• Foodborne diarrheal disease agents, particularly non-typhoidal Salmonella enterica, caused 230,000 (95% UI 160,000–320,000) deaths
• Other major causes of FBD deaths were Salmonella Typhi, Taenia solium, hepatitis A virus and aflatoxin.
• 40% of the FBD burden was among children under 5 years old.
• The African (AFR), South-East Asian (SEAR) and Eastern Mediterranean (EMR) D subregions had the highest FBD burden.
• Diarrheal disease agents were the leading cause of FBD burden in most subregions, and non-typhoidal Salmonella enterica caused an important burden in all subregions, particularly in the subregions in Africa.
• Other main causes of diarrheal FBD burden were enteropathogenic Escherichia coli, enterotoxigenic Escherichia coli and Vibrio cholerae in low-income subregions, and Campylobacter spp. in high-income subregions.
• The burden of aflatoxin was high in the AFR D, Western Pacific (WPR) B and SEAR B subregions, whereas dioxins caused the highest burden in SEAR D, EMR D and European (EUR) A and C subregions.
• In the South-East Asian subregions, there was a considerable burden of Salmonella Typhi; the burden of Opisthorchis spp. was concentrated in the SEAR B region, where the seafoodborne trematodes Paragonimus spp. and Clonorchis sinensis were also important.
• In Central and South American (AMR B and AMR D) subregions, T. solium and Toxoplasma gondii contributed significantly to the FBD burden.
• These estimates should inform policy development at national and international levels to improve food safety throughout the food chain.

     

Protective Role of Capsaicin in Neurological Disorders: An Overview

Neurochemical Research - Different pathological conditions that begin with slow and progressive deformations, cause irreversible affliction by producing loss of neurons and synapses. Commonly it is...     

World Health Organization Estimates of the Global and Regional Disease Burden of 11 Foodborne Parasitic Diseases, 2010: A Data Synthesis

Background

Foodborne diseases are globally important, resulting in considerable morbidity and mortality. Parasitic diseases often result in high burdens of disease in low and middle income countries and are frequently transmitted to humans via contaminated food. This study presents the first estimates of the global and regional human disease burden of 10 helminth diseases and toxoplasmosis that may be attributed to contaminated food.

Methods and Findings

Data were abstracted from 16 systematic reviews or similar studies published between 2010 and 2015; from 5 disease data bases accessed in 2015; and from 79 reports, 73 of which have been published since 2000, 4 published between 1995 and 2000 and 2 published in 1986 and 1981. These included reports from national surveillance systems, journal articles, and national estimates of foodborne diseases. These data were used to estimate the number of infections, sequelae, deaths, and Disability Adjusted Life Years (DALYs), by age and region for 2010. These parasitic diseases, resulted in 48.4 million cases (95% Uncertainty intervals [UI] of 43.4–79.0 million) and 59,724 (95% UI 48,017–83,616) deaths annually resulting in 8.78 million (95% UI 7.62–12.51 million) DALYs. We estimated that 48% (95% UI 38%-56%) of cases of these parasitic diseases were foodborne, resulting in 76% (95% UI 65%-81%) of the DALYs attributable to these diseases. Overall, foodborne parasitic disease, excluding enteric protozoa, caused an estimated 23.2 million (95% UI 18.2–38.1 million) cases and 45,927 (95% UI 34,763–59,933) deaths annually resulting in an estimated 6.64 million (95% UI 5.61–8.41 million) DALYs. Foodborne Ascaris infection (12.3 million cases, 95% UI 8.29–22.0 million) and foodborne toxoplasmosis (10.3 million cases, 95% UI 7.40–14.9 million) were the most common foodborne parasitic diseases. Human cysticercosis with 2.78 million DALYs (95% UI 2.14–3.61 million), foodborne trematodosis with 2.02 million DALYs (95% UI 1.65–2.48 million) and foodborne toxoplasmosis with 825,000 DALYs (95% UI 561,000–1.26 million) resulted in the highest burdens in terms of DALYs, mainly due to years lived with disability. Foodborne enteric protozoa, reported elsewhere, resulted in an additional 67.2 million illnesses or 492,000 DALYs. Major limitations of our study include often substantial data gaps that had to be filled by imputation and suffer from the uncertainties that surround such models. Due to resource limitations it was also not possible to consider all potentially foodborne parasites (for example Trypanosoma cruzi).

Conclusions

Parasites are frequently transmitted to humans through contaminated food. These estimates represent an important step forward in understanding the impact of foodborne diseases globally and regionally. The disease burden due to most foodborne parasites is highly focal and results in significant morbidity and mortality among vulnerable populations.