Neurological conditions, including strokes, migraines, and dementia, have now overtaken heart disease as the top cause of disability and ill health globally, according to a comprehensive study released on Friday. In 2021, over 3.4 billion people, which represents 43 percent of the world’s population, were found to be suffering from a neurological condition. This number is significantly higher than previous estimates. The research was conducted by a large team of experts led by the Institute for Health Metrics and Evaluation (IHME) in the United States, a key source for health data worldwide.
Jaimie Steinmetz, the lead author of the study from IHME, highlighted that conditions of the nervous system have become the primary contributors to the global disease burden. Over the past thirty years, there has been a 59 percent increase in cases of these conditions. This rise is largely attributed to the rapid aging and growth of the global population. The study examined 37 different neurological conditions and their impact on health, disability, and early death in 204 countries and territories from 1990 to 2021.
Researchers used this data to calculate the number of healthy life years lost to each condition, known as disability-adjusted life years (DALYs). In 2021, neurological disorders were responsible for the loss of more than 443 million years of healthy life worldwide, marking an 18-percent increase since 1990. However, when adjusting for the age and size of the population, the study found that DALYs and deaths from these conditions actually decreased by about a third.
Stroke was identified as the most severe neurological condition, responsible for 160 million years of healthy life lost. It was followed by neonatal encephalopathy, migraine, dementia (including Alzheimer’s disease), diabetic nerve damage, meningitis, and epilepsy. Cognitive issues following Covid-19 were ranked 20th. A significant factor in neurological conditions surpassing cardiovascular diseases in this analysis was the recent reclassification by the World Health Organization, which moved stroke to the neurological category.
The substantial loss of healthy years from these conditions is partly due to their ability to affect children under five, with conditions like neonatal encephalopathy, asphyxia, or meningitis being particularly deadly. Steinmetz pointed out that deaths at a young age contribute significantly to the total years of life lost. Children made up nearly a fifth of all healthy years lost, according to the study.
In 2021, the 37 neurological conditions studied were responsible for more than 11 million deaths. However, cardiovascular diseases remained the leading cause of death, with 19.8 million deaths worldwide in 2022, as reported by the IHME. Tension headaches and migraines were the most common neurological disorders, with diabetic neuropathy, a type of nerve damage caused by diabetes, being the fastest-growing condition.
Despite the lack of cures for most of these conditions, the study suggests ways to reduce risk, such as lowering high blood pressure, diabetes, and alcohol consumption rates. The researchers emphasized the need for more efforts to prevent, treat, and rehabilitate these disorders, which disproportionately affect poorer countries. Valery Feigin, a co-author of the study, warned that the global burden of neurological conditions is rapidly increasing and will place even more strain on health systems in the future.