Universities should be bound by law to meet the mental-health needs of their students, an ex-health minister says.
Information gathered by Sir Norman Lamb's office reveals a "complex and fragmented" picture of mental-health provision across UK universities.
Many of the 110 universities which responded said they did not record all relevant key statistics, such as their budgets or waiting times.
Universities said they could not deal with the issue of mental health alone.
They added that they were already working on a voluntary mental-health charter.
It comes as an inquest opens into the suicide of a 19-year-old student.
Ceara Thacker, originally from Bradford, took her own life in May 2018 while studying at Liverpool University after her mental health deteriorated.
She had struggled with it earlier in her teenage years, and attempted suicide in the February before her death.
'In a fog'
Mental-health campaigner Sir Norman obtained information from 110 universities, under freedom-of-information laws, on the demand for, and investment in, mental-health support for their students.
The responses revealed that many universities did not monitor how well services were used, or whether they were meeting the needs of students.
And while some, such as Bristol, Kingston and Sussex, are spending more than £1m a year on well-being services, including counselling, others have a budget of less than half that.
Many did not even know how much they spent on mental health, and only a handful of universities could supply information on how long students were waiting for counselling.
For the few that did, the longest wait was, on average, 43 days - more than half the length of a standard university term.
Sir Norman praised some universities, including Cambridge and Northumbria, for taking their responsibilities seriously, but said many others were not doing enough to measure the scale of the problem.
"If we are operating in a fog, if we have no idea how long students are waiting... this is putting students at risk," he added.
"We know from the data that the longest waiting times could be over half a term for some students.
"We know also that there have been some tragedies among some student populations - students who have taken their own lives.
"If that happens while they are waiting for support, that's utterly intolerable."
Duty of care
He added: "These are young people at a vulnerable age, many living away from home for the first time. There is a risk of some students self-harming, or some students finding themselves in a desperate situation and taking their own lives."
He pointed out that students paying high fees had every reason to expect a duty of care from their universities.
He is calling for a legally binding charter with minimum standards that universities are required to meet, so parents know their adult children will be safe.
A spokesman for Universities UK said: "Funding to support mental-health services at universities will vary depending on the needs of each student population.
"Universities cannot address these challenges alone.
"The NHS must provide effective mental-health care to students, and Universities UK is working closely with NHS England to ensure that commitments in the NHS long-term plan are implemented."
