Administering an exam used to be straightforward: All a college professor needed was an open room and a stack of blue books. At many American universities, this is no longer true. Professors now struggle to accommodate the many students with an official disability designation, which may entitle them to extra time, a distraction-free environment, or the use of otherwise-prohibited technology. The University of Michigan has two centers where students with disabilities can take exams, but they frequently fill to capacity, leaving professors scrambling to find more desks and proctors. Juan Collar, a physicist at the University of Chicago, told me that so many students now take their exams in the school’s low-distraction testing outposts that they have become more distracting than the main classrooms.

Recently, mental-health issues have joined ADHD as a primary driver of the accommodations boom. Over the past decade, the number of young people diagnosed with depression or anxiety has exploded. L. Scott Lissner, the ADA coordinator at Ohio State University, told me that 36 percent of the students registered with OSU’s disability office have accommodations for mental-health issues, making them the largest group of students his office serves. Many receive testing accommodations, extensions on take-home assignments, or permission to miss class. Students at Carnegie Mellon University whose severe anxiety makes concentration difficult might get extra time on tests or permission to record class sessions, Catherine Samuel, the school’s director of disability resources, told me. Students with social-anxiety disorder can get a note so the professor doesn’t call on them without warning.

The types of accommodations vary widely. Some are uncontroversial, such as universities outfitting buildings with ramps and providing course materials in braille. These allow disabled students to access the same opportunities as their classmates. Some students get approved for housing accommodations, including single rooms and emotional-support animals.

Other accommodations risk putting the needs of one student over the experience of their peers. One administrator told me that a student at a public college in California had permission to bring their mother to class. This became a problem, because the mom turned out to be an enthusiastic class participant.

Professors told me that the most common—and most contentious—accommodation is the granting of extra time on exams. For students with learning disabilities, the extra time may be necessary to complete the test. But unlike a wheelchair ramp, this kind of accommodation can be exploited. Research confirms what intuition suggests: Extra time can confer an advantage to students who don’t have a disability.