Aug 5, 2023 - Health

Study: Half of all people likely get mental illness in their lifetime

Man with head in hands.

A man sits huddled on a chair with his hands in front of his face. Photo: Jonas Walzberg/picture alliance via Getty Images

About half of the world's population "can expect to develop" at least one type of mental disorder by the time they are 75 years old, according to a new study published in the scientific journal The Lancet Psychiatry.

Why it matters: The number of Americans experiencing mental health challenges has risen in recent years, particularly during the pandemic. The study finds evidence that certain disorders — such as depression and addiction — are also on the rise at the global level.

  • Of the 13 disorders included in the survey, the most common among women were depression, a specific phobia — defined as "a disabling anxiety that interferes with daily life" — and post-traumatic stress disorder.
  • For men, the most common were alcohol abuse, depression and a specific phobia.

Driving the news: For the study, published this week, researchers at the University of Queensland and Harvard Medical School analyzed data from the World Health Organization's World Mental Health surveys.

  • That data set is the largest coordinated series of face-to-face surveys on this issue, with over 150,000 adults from 29 countries participating over two decades.
  • Survey participants took part in fully structured psychiatric diagnostic interviews to determine the age at which these illnesses first appeared, how prevalent they are, and the morbidity risk by age 75.
  • Mental disorders "typically first emerge in childhood, adolescence, or young adulthood," according to the findings — more specifically, the median age at which disorders emerged was 19 for men and 20 for women.

What they found: 1 in 2 people were estimated to have at least one mental illness, according to the researchers' analysis of the WHO data, which was not previously known. It's a sharp increase from 1 in every 8 people worldwide in 2019.

  • "The most common were mood disorders such as major depression or anxiety," said study lead author John McGrath, a professor at UQ's Queensland Brain Institute, in a statement. "We also found the risk of certain mental disorders differed by sex."

What they're saying: "By understanding the age at which these disorders commonly arise, we can tailor public health interventions and allocate resources to ensure that appropriate and timely support is available to individuals at risk," McGrath said.

  • Brett Emmerson, a professor and chair at the Royal Australian and New Zealand College of Psychiatrists' Queensland branch, noted to the Australian Broadcasting Corporation that the new research indicated that mental illness affects more people than previously known.
  • "If half of the population will have a disorder, then you have to start looking at what treatments there are," he added. "Early intervention is better because if you leave it, you risk the disorder becoming chronic."

Our thought bubble, via Axios' Tina Reed: Mental health disorders, including depression, anxiety and substance abuse disorders, were already soaring but reached crisis levels as they were exacerbated by the COVID-19 pandemic.

Between the lines: An estimated 1 in 5 adults in the U.S. live with a mental illness, and more people are seeking therapy. However, mental health providers are struggling to keep up with the demand.

What we're watching: The Biden administration proposed a rule earlier this month to require health insurers to cover behavioral health at the same level as physical health in an effort to address this.

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