University support services have warned they are unable to meet demand from students facing increasing pressures of debt and stress.
A National Union of Students study found 75% of managers at student helplines and counselling centres reported a major increase in uptake.
About 40% of the service providers asked said they were unable to cope with the level of demand.
The NUS urged ministers not to implement spending cuts to services.
They said resources were not keeping pace with escalating demand and that many students could drop out of their studies as a result.
The union's Silently Stressed report found that demand for mental health and stress support had increased markedly over the past year.
Jennifer Cadiz, deputy president of NUS Scotland, said the figures showed support services were struggling to cope.
"Three-quarters of services reported an increase in students using their services due to mental illness or stress and almost half said they couldn't meet demand," she added.
"At the same time less than a third of students felt able to go to their lecturer or institution for help. This is incredibly worrying."
Ms Cadiz said: "Ahead of next week's Scottish budget it's absolutely crucial that politicians, as well as college and university principals, prioritise funding for these vital student support services.
"If we are to tackle the growing problem around student mental health then we must be clear that student mental health services are a necessity for thousands, not a luxury we can afford to see damaged by cuts."
According to the research, 90.5% of students said they suffered stress over exams and assessments, while 75% said they were stressed at their career prospects.
More than 80% said they were worried about managing their time and deadlines, with 68.2% saying they suffered stress over the amount of money they had to get by.