Across America, college counseling centers are strained by rising numbers of mentally ill students and surging demand for mental health services — a challenging trend as campus officials try to identify potential threats like the unstable Virginia Tech gunman.

And even when serious emotional problems are detected, university officials often feel constrained in how they respond due to an array of laws and policies protecting students' rights and privacy.

"The number of people coming to colleges who've had psychiatric treatment has increased tremendously," said Dr. Gerald Kay, a psychiatry professor at Wright State University and chair of the American Psychiatric Association committee on college mental health.

"Now they're able to come to college — that would not have been the case earlier," Kay said. "You've got a very large number of people who may have some vulnerabilities. It has stressed the availability of resources."

Reasons for the surge include the Americans with Disabilities Act, which gives mentally ill students the right to be at college, and increasingly sophisticated medications which enable them to function better than in the past.

Recent surveys and studies underscore the scope of the increase.

A survey last year by the American College Health Association found that 8.5 percent of students had seriously considered suicide, and 15 percent were diagnosed for depression, up from 10 percent in 2000. The Anxiety Disorders Association of America found that 13 percent of students at major universities and 25 percent at liberal arts colleges are using campus mental health services.

Dr. Chris Flynn, director of Virginia Tech's counseling center, has declined to discuss details of gunman Cho Seung-Hui's case, but said the center's staff — which includes a psychiatrist and 11 psychologists — treats about 2,000 students per school year.

In December 2005, a magistrate ordered Cho to undergo an evaluation at a private psychiatric hospital after two women complained about annoying calls from him, and an acquaintance reported he might be suicidal. An initial evaluation found probable cause that Cho was a danger to himself or others as a result of mental illness, but court papers indicate he was free to leave the hospital within days — a step allowed only if hospital officials judged him no longer a danger.

"We have to provide services to students with mental illness — it's not grounds to exclude them from our property," Flynn said. "We cannot discriminate against the mentally ill, nor do we want to."

He said the type of complaints lodged against Cho by the two women are a common and challenging phenomenon on campuses nationwide.

"It is very difficult to predict when what someone perceives as stalking is stalking, and then how it might translate into violence later," Flynn said. "Clearly, if anyone had any warning about a violent incident, people would have stepped in and acted."

Psychologist Sherry Benton, assistant director of counseling services at Kansas State University, has conducted research concluding that students' mental health problems are more complex and severe than 20 years ago.

"We're well aware that problems are getting worse, but what hasn't happened is increasing funding for mental health services," she said. "Most centers are now overwhelmed. Business has gone up and up, but budgets have remained the same or been cut, and that's a huge problem."

One factor, Benton said, is that mental health services are usually not among the categories assessed during colleges' periodic accreditation reviews. If schools needed good services to remain accredited, they might invest more, she said.

Benton views the rising demand for campus mental health services as a good news-bad news development.

"We do get a lot more students into college who have mental illness but are no problem whatsoever," she said. "They do need support and use medication; they go on to lead full, productive lives."

On the downside, she and her colleagues see stress levels among students far higher than a generation ago due to increased workloads and financial strains, often coupled with lack of healthy lifestyles.

Complicating the overall picture is a web of laws and policies that limit the options for worried staff members. Troubled students generally can't be forced to obtain treatment, and privacy laws may limit sharing information about them, even to the extent that some parents have sued schools — including the Massachusetts Institute of Technology and the Oregon Institute of Technology — for not advising them of their children's serious disorders.

Nonetheless, officials on many campuses have set up committees to pool information about students with emotional or behavioral problems so patterns can be detected in what might otherwise be seen as isolated incidents. The trick, officials say, is to find the proper balance between respecting a student's rights and protecting the university.

"That's the tightrope administrators have to walk," said Wright State's Gerald Kay.

"The issue in most instances is how do you bring these people into some sort of treatment."

Benton said any student who issues threats should be dealt with forcefully, regardless of privacy guidelines.

"Safety trumps confidentiality every time," she said. "If someone is a danger to themselves or others, then confidentiality is out the window and you notify who you need to notify to ensure the safety of them and those around them."

Peter Lake, a law professor at Stetson University, contends that officials on many campuses have been too deferential to privacy concerns, at the risk of safety at their schools.

"There's a false consciousness of privacy in higher education — as an institution, we don't like to share information," he said.

"Now, you're going to be seeing a greater emphasis on a management team or a safety czar — someone whose job it is to look at students' overall profiles," Lake said. "It's not only a good idea — it's an idea we can't live without."