Malachi Kamler, from Ft. Wayne, joins protesters Tuesday, Aug. 12, 2025 outside Miami Correctional Facility in Bunker Hill, Ind. They protested against plans to use Miami Correctional as an ICE detention center.

Immigration detention centers are holding more people in solitary confinement than had been believed, and the practice is growing.

New data show thousands more immigrants were held in solitary confinement under the Biden administration than had been reported, and the use of "segregation" tactics remains high under the Trump administration – despite the documented dangers to human health.

"The more data that is released the worse we realize it is," said Dr. Katherine Peeler, medical adviser for Physicians for Human Rights and assistant professor of pediatrics at Harvard Medical School.

The Trump administration has dramatically increased the use of ICE detention amid a nationwide immigration crackdown. Roughly 60,000 people are in ICE detention now on any given day, up from fewer than 40,000 people this time last year.

The number of people placed in solitary has risen at the same time, but so too has their share of the overall detained population, according to the new report by the nonprofit Physicians for Human Rights and Harvard University researchers.

Alarmingly, researchers say, the data shows people who constitute "vulnerable populations" – which can include people with mental health conditions, medical illness or who face risks in the general population – are now spending, on average, twice as much time in solitary confinement compared with others in solitary.

U.S. Immigration and Customs Enforcement didn't respond to an emailed request for comment. However, ICE historically has maintained that it doesn't use "solitary confinement." The agency reports every month the number of people held in "segregation."

But people segregated from the general population "are in an isolated cell, locked in, with no control over their environment," which is the definition of solitary confinement, Peeler said.

ICE defines "vulnerable" detainees as those who are pregnant, nursing or elderly; who have serious mental health conditions or medical illness; who are at risk of harm because of their identity; or who are victims of sexual assault or abuse.

Isolation can have serious health consequences

The average consecutive days of solitary confinement for people with vulnerabilities surged last year to more than 40 days, according to the report, from fewer than 20 days when ICE began reporting these placements in 2022. The average length of stay remained elevated in the first few months of the Trump administration, near 40 days.

Human rights experts recognize 15 days as the threshold for when solitary confinement should be considered torture, according to the ACLU.

The agency maintains that use of segregated housing "is a serious step that requires careful consideration of alternatives," according to its own 2022 guidance, which added that "administrative segregation due to a special vulnerability should be used only as a last resort."

Decades of research have revealed the devastating effects of solitary confinement on the human mind and body.

Prolonged isolation in detention can provoke psychological symptoms, including paranoia, PTSD and depression, that can lead to suicide, Peeler said.

From the standpoint of physical health, "chronic conditions can get worse in solitary confinement," she said. "It's bad all around, in all senses."

Other researchers have found high rates of solitary confinement among detained immigrants.

In 2021, researchers conducted a phone survey of 203 immigrants who had been held in immigration detention. More than half reported suffering from depression or PTSD as a result, and 45% reported having experienced solitary confinement during their detention, according to a study published in 2025 in the Journal of Migration and Health.

Increasing reliance on solitary confinement

The United States has the world's largest immigration detention system, and the Trump administration is expanding it further.

With billions in new funding from Congress, the administration plans to add another 80,000 beds to the system, which would allow ICE to detain more than 140,000 people a day.

"We've heard from detainees about the conditions in detention deteriorating," said Eunice Hyunhye Cho, senior counsel for the ACLU's National Prison Project. "It's in the context of a situation where detention is rapidly expanding, and there is less oversight and less incentives for facilities to be as protective of people as possible."

Solitary confinement "is a barometer" of stress in the detention system, she said. "It's used for a lot of purposes when facilities are under stress, when officers are trying to control issues or problems or to impose punitive order in a facility where other supports may be deteriorating."

The use of solitary confinement began climbing before Trump took office, said Arevik Avedian, a coauthor of the report and director of Empirical Research Services at Harvard Law School.

The data she and other researchers obtained through a Freedom of Information Act request encapsulated a 14-month period between April 2024 and May 2025, spanning the end of the Biden administration and beginning of the second Trump administration. More than 10,500 people spent time in solitary confinement at detention centers across the country in that time frame.

The data reveal an increasing reliance on solitary confinement beginning in 2021, Avedian said, and 2024 set a record.

New regulations in December 2024 required ICE to begin reporting every person held in solitary, regardless of the duration or their vulnerability. The numbers immediately soared and were 80% higher, on average, than before the policy change, according to the report – suggesting that hundreds or thousands of instances of solitary confinement had gone uncounted, researchers found.

"We wanted to see how much are things getting worse or better," Avedian told USA TODAY. "So far, we are seeing that things are getting worse."

Lauren Villagran can be reached at lvillagran@usatoday.com.

This article originally appeared on USA TODAY: More immigrants are being locked up alone. And the practice is growing.

Reporting by Lauren Villagran, USA TODAY / USA TODAY

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