The COVID-19 pandemic is leading to a sharp rise in people seeking help for mental health issues, experts tell The Washington Post.

Mental health professionals are warning that the nation will see a historic wave of increases in depression, substance use, post-traumatic stress disorder and suicide. The U.S. mental health system is unprepared, according to Susan Borja, who leads the traumatic stress research program at the National Institute of Mental Health.

“That’s what is keeping me up at night,” she said. “I worry about the people the system just won’t absorb or won’t reach. I worry about the suffering that’s going to go untreated on such a large scale.”

About 20,000 people texted the federal government’s disaster distress hotline last month—a 1,000% increase from the previous year, according to the Substance Abuse and Mental Health Services Administration.