Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

Burden and Epidemiology of Mental Disorders in the Middle East and North Africa from 1990 to 2019: Findings from the Global Burden of Disease Study

Background: Previous studies have mainly focused on individual mental disorders, and there is no study addressing the total burden of mental disorders in the Middle East and North Africa (MENA). Aims: To evaluate the burden of mental disorders in the MENA region from 1990 to 2019. Study Design: A cross-sectional study. Methods: We utilized global burden of disease data to examine the burden of 12 mental disorders from 1990 to 2019 across age groups, genders, and the 21 MENA countries. We collected data on prevalence, incidence, mortality, years of life lost, years lived with disability, and disability-adjusted life-years (DALY), including both crude and age-standardized rates per 100,000 people. Results: The DALY rate of mental disorders in MENA countries increased by 13.88% from 1,747.92 per 100,000 people in 1990 to 1990.5 per 100,000 people in 2019. The highest percentage increases in the DALY rates of mental disorders were observed for bulimia nervosa (35.69%), other mental health disorders (34.58%), and schizophrenia (33.02%) from 1990 to 2019. However, the DALY rates for idiopathic developmental intellectual disability (-26.48%), conduct disorder (-23.91%), attention-deficit/hyperactivity disorder (-16.46%), and autism spectrum disorders (-4.12%) decreased in the MENA region from 1990 to 2019. In 2019, the highest DALY rates for idiopathic developmental intellectual disability, anxiety disorders, and major depressive disorder were observed in age groups ≤ 4 years, 5-19 years, and ≥ 20 years, respectively. The age-standardized DALY rate of mental disorders was the highest in Palestine (2,396.9 per 100,000), Iran (2,295.8 per 100,000), and Lebanon (2,126.0 per 100,000) compared with other MENA countries in 2019. Conclusion: There has been a slight increase in the burden of mental disorders in the MENA region between 1990 and 2019. National policies should prioritize evidence-based preventive measures and ensure accessible treatment options for mental health disorders in the population, especially in the MENA region

Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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