When her daughter was in high school, Susan Hein occasionally asked if she was remembering to take her antidepressants. But Hein didn't count pills. She knew her daughter was on top of the regimen.

Hein hoped the same would continue in college. But on campus at Johnson and Wales University in Providence, R.I., her daughter feared being recognized by friends when she visited the counseling center or a nearby pharmacy.

"That gave her so much anxiety that she couldn't deal with it," her mother said. "She stopped taking her medication. And she didn't want to see anyone for counseling."

Soon, Hein said, the panic attacks that had been moderated by medication became constant. Her daughter went to the emergency room fearing she was having a heart attack. Two more emergency visits followed. Finally, a doctor recommended she get psychiatric help. She was diagnosed with bipolar disorder and panic disorder, and resumed medication and therapy.

Everything worked out for her, but her experience is becoming increasingly common, mental health experts say. More students than ever before are entering college with pre-existing mental health conditions, and medication can be an important component of their care. But many students stop taking medications when they arrive on campus — the exact moment when their stress levels shoot up.

"They don't want to be seen as someone with a problem," said Dr. Bruce Cohen, a psychiatrist at McLean Hospital in Massachusetts, where hundreds of college students from across the country are treated for mental illness each year.

It has become an increasingly frequent issue over the past two decades, as more teens are given medication for mental illness, Cohen said. A study of national data found the use of psychotropic medication in adolescents rose from 14 percent in the 1990s to 20 percent in the mid-2000s.

"We are now able to help students enough that they actually get into college, whereas 20 years ago, they wouldn't have," Cohen said.

But once they get there — removed from family members who may have ensured that they take their medication and facing a new environment with new schedules and priorities — "a large proportion of students try stopping," Cohen said.

Some, like Hein's daughter, fear the stigma associated with others knowing they have a mental illness. Others convince themselves that they don't need medication anymore, said Matthew Wintersteen, a clinical psychologist at Thomas Jefferson University in Philadelphia.

"Feeling you have to take a medication to manage your mood is challenging for kids who are trying to become independent," he said.

But many students don't realize there are consequences to abruptly stopping medication, Cohen said. It's in part because their effects fade slowly. "A few days you don't take it and you don't feel terrible," he said. "So you think maybe you don't need it."

After some time, though, students can experience more frequent or longer periods of depression, anxiety attacks or other symptoms associated with their illness. These effects can be compounded by students ending counseling, as well, rather than trying to find a new therapist at college. Some people also suffer side effects from suddenly stopping antidepressants, ranging from headaches to flu-like symptoms that can last weeks.

This doesn't mean that students can never stop or change their medication, Wintersteen said. In fact, parents should be open-minded about kids' wanting to change their routines as they get older. But it needs to be done with the help of professionals and at the right time, he said. Ideally, students should acclimate to college life first.

Universities can play a role too, Cohen said. Once a student enrolls, counseling centers should ask if they are on treatment, and make a point of following up with them. It's not something many universities do now, but it could relieve some of the demand for counseling services later in the semester, Cohen said.

"It's much more expensive to address the problem after someone is off their meds," he said. "If you took preventive measures so people wouldn't get in trouble, then resources wouldn't be stretched as thin."