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Half of people will develop mental illness by 75, study finds

Steph Whiteside

FILE - Stanford women's soccer team players wear warmup jerseys with "Mental Health Matters" on their backs as well as a butterfly patch on their sleeves to remember late goalie Katie Meyer, who died by suicide earlier in the year, before an NCAA college soccer match against UCLA, Oct. 14, 2022, in Stanford, Calif. The COVID-19 pandemic took an especially harsh toll on U.S. teen girls’ mental health, with almost 60% reporting feelings of persistent sadness or hopelessness, according to a government survey released Monday, Feb. 13, 2023, that bolsters earlier data. (Yalonda M. James/San Francisco Chronicle via AP, File)

(NewsNation) — Half of the population will experience a mental illness by the age of 75, according to new research.

Researchers from Harvard University and the University of Queensland studied people from 29 countries over a 21-year period and determined one in two people will experience mental illness by the age of 75.

For many people, the illness will come much earlier in life. Researchers identified the median age of onset as 19 for men and 20 for women, with the peak age of onset at 15.

The most common mental illnesses among men were substance use disorders, depression and specific phobias.

Among women, the most common illnesses specific phobias and depression, along with post-traumatic stress disorder.

Researchers said the findings should be used to help develop public health interventions in hopes of making it easier to identify illnesses in adolescence, when they are likely to first appear and to connect people with treatment resources.