The Globe's Leading Illnesses Are in Our Heads

The leading cause of all ill health and disability around the globe isn't cancer or heart disease—it's a wide umbrella of neurological conditions, ranging from migraines to strokes, dementia, or Parkinson's, among other maladies. Per a new study published Thursday in the Lancet, scientists found that 43% of the world's population, or about 3.4 billion people, were living with or dying from nervous systems disorders in 2021, with 11.1 million resulting deaths. The research, part of the "Global Burden of Disease" study, found that the amount of sickness, disability, and early death caused by more than three dozen neurological disorders jumped more than 18% from 1990 to 2021.

The researchers looked at mortality, prevalence, years that patients had lived with their conditions, and "disability-adjusted life-years," or DALYs, among other factors, in more than 200 countries over the 31-year span, per MedPage Today. The 10 conditions with the most DALYs include stroke in the No. 1 spot, followed by neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications from preterm birth, autism spectrum disorder, and nervous system cancer.

The most common neurological disorders are tension headaches, which accounted for about 2 billion cases in 2021; migraines followed closely behind, with 1.1 billion cases. Four-fifths of neurological health loss and deaths take place in poor and middle-income nations. "These figures are really concerning and underline the need for urgent action," Dr. Leah Mursaleen, head of research at Alzheimer's Research UK, tells the Guardian. "Given that many of the conditions included in our analysis do not have cures, prevention by addressing modifiable risk factors is key," study co-author Jaimie Steinmetz tells MedPage Today. (More discoveries stories.)