How can I make my thesis better? Any ideas?

Well, it IS weak. First, you have to support your claim that depression is increasing on college campuses as compared with, say, 20 years ago. For that, you must do serious research in journals, books, and -- I would suggest -- interviews with counselors and therapists on your campus. You need both statistics and professional points-of-view.

If you can support this statement, then obviously more support for depressed students is needed. That goes without saying. If I were you, I would focus on DOCUMENTING an increase in rates of depression among college students and coming up with hypotheses to explain these increased rates. You might also look at increases, if any, in specific types of depression among students. For example, is there an increase in the rate of bipolar disorder among college students? Why might that be? Are bipolar students being identified in high school, medicated then, and able to attend college as a result? If so, how are they being supported and monitored while in college? Are student health services having to come up with new means of dealing with students who suffer from bipolar disorder?

You need to be rigorous and serious in a thesis. It's not enough to make a general statement of the kind you offered. Choose a narrow area on which to focus and research it with care, offering both primary (interviews) and secondary (books and articles) sources.

Get some hard evidence that depression is a growing problem in students to back up your claim. Find some statistics, numbers, percentages, graphs. Get the names of experts such as psychologists who have made this claim. Have other colleges or places of study implemented support for this? Is there less incidence of depression where there are college counselling services? Find some arguments against the view, some from articles and some of your own, for example that depression isn't increasing but rather, as it is a more acceptable condition more students are prepared to admit that they are suffering from it. There may be other counter arguments. Is there a relationship between the percentage of depressed students and the type of educational establishment (eg: level of education, reputation of college). Try to discover through online reading what tends to be the probable cause of the depression: pressure of study, loneliness (perhaps especially among first year students away from home and those who do not easily make friends), worry about exams, etc. Think about everything you read and comment on anything which you think doesn't follow logically, any gaps, anything you disagree with.

Add your own ideas and back them up with reasoning and your own observations.Include your own: theories about why the increase in depression may be occurring, criticisms (positive and negative) of the reports and news articles which describe this, ideas about what type of support would be most beneficial and why, etc.

For everything you use in your thesis which has been written by someone else (articles you mention, ideas you've read about, statistics, etc.) give their source. Don't use anything you find online (don't say "Joe Pratt in his blog says..." !) but do use news articles, psychologist reports, articles from reputable magazines such as New Scientist, and so on.