COVID-19 is taking a heavy toll on Americans' mental health, a new nationwide survey shows. 

Overall, psychological distress more than tripled between 2018 and this spring — from 4% of U.S. adults in 2018 to 14% in April. 

Beth McGinty, an associate professor at Johns Hopkins Bloomberg School of Public Health in Baltimore, said the findings, from a survey of 1,500 adults, suggest the need to prepare for a wave of mental illness once the pandemic passes.

"It is especially important to identify mental illness treatment needs and connect people to services, with a focus on groups with high psychological distress including young adults, adults in low-income households, and Hispanics," McGinty said in a university news release.

The survey used a scale to gauge feelings of emotional suffering as well as symptoms of anxiety and depression.

It found that distress was especially acute among younger adults. Among 18- to 29-year-olds, 24% reported feelings of distress this spring, compared to 4% in 2018, researchers found. 

Lower-income households also were keenly feeling the impact of the pandemic. Distress rose from less than 8% in 2018 to 19% in homes with a yearly income of less than $35,000, the survey found. 

And 18% of Hispanics reported psychological distress in 2020, up from 4% in 2018.

Among Americans age 55 and older, psychological distress nearly doubled between 2018 and April — rising from nearly 4% to over 7%.

"The study suggests that the distress experienced during COVID-19 may transfer to longer-term psychiatric disorders requiring clinical care," McGinty said.

The findings were published online June 3 in the Journal of the American Medical Association.