Immigrant detention centers nationwide are reporting placing more people in solitary confinement in 2025, sometimes for weeks at a time, according to new research.
The big picture: U.S. solitary confinement placements increasingly drag on for 15 days or longer, which the United Nations says constitutes psychological torture, according to a report by Harvard University researchers and Physicians for Human Rights.
- The researchers focused on immigrant detention centers, which experts say are primarily used to hold immigrants and ensure they make their court hearings and check-ins — not to punish them for immigration violations.
Driving the news: Nearly 14,000 people were placed in solitary confinement in immigrant detention centers nationwide between April 2024 and August 2025, per new data provided exclusively to Axios.
- Researchers detailed an increase in solitary confinement placements and, for some populations, weeks-long isolation periods, in a recent report that focused on data between April 2024 and May 2025.
- The report, which relies on ICE's data collections, didn't show the duration of solitary confinement placements for all detainees, just for those labeled as "vulnerable," like those with mental health issues.
Zoom in: Those labeled "vulnerable," who make up one-fifth of detainees between April 2024 and May, were placed in solitary confinement for an average of 38 days in the first three months of 2025.
- In 2021, the average duration was 14 days, per the report.
- ICE's own directives suggest using solitary confinement on people with mental health conditions only as a last resort.
- This often happened in state and county jails contracting with U.S. Immigration and Customs Enforcement (ICE) to hold detainees.
Caveat: Researchers also warn that ICE data is typically incomplete, suggesting there could be an undercount of solitary confinement placements.
By the numbers: The report found that Moshannon Valley Processing Center in Philipsburg, Pennsylvania, had the highest number of people isolated (1,905) through May.
- Montgomery Processing Center in Conroe, Texas, had the second-highest (1,075), followed by Buffalo Service Processing Center (642) in Batavia, New York, and South Texas ICE Processing Center in Pearsall, Texas (488).
What they're saying: "We are torturing people simply because they want a better life in the U.S.," says Sam Zarifi, executive director of Physicians for Human Rights, a New York-based organization that uses medicine to advocate against human rights violations.
- Solitary confinement is not only horrific treatment of people, he added, but violates U.S. and international law.
- ICE didn't respond to several emails from Axios seeking comment.
The other side: Some jails and prisons, like in Massachusetts, say they have shifted away from solitary confinement and instead practice "administrative segregation," which involves separating detainees believed to pose a threat to safety, property or correctional operations.
- Massachusetts officials say segregated detainees regularly interact with staff clinicians and sometimes inmates, and that they have daily access to mental health clinicians.
Yes, but: Prisoner advocates say "administrative segregation" is just a euphemism for solitary confinement, and that the differences are minimal.
What's next: The report urged state and local officials to use their own power to end or reduce the use of solitary confinement in local facilities with ICE contracts.
- The report also suggested unplanned facility inspections by local officials and steps to ensure detainees have legal representation, interpreters and due process protections.
The bottom line: "ICE detention facilities are systemically torturing people and are on track to be torturing more people, and these are people who are not imprisoned for criminal activity," Zarifi said.
- "They are asylum seekers and immigrants."
