How do I make my thesis statement more specific?

Help me make a good thesis statement?

• I am doing an essay on Signs of Depression shown in Catcher in the Rye through Holden Caulfield. (**great book by the way**) but I am used to making three prong thesis statements, however for this topic we have to make a ONE prong thesis statement and I am having a little difficulty. This is what I currently have for the introduction, if anyone could give me any ideas for a one prong thesis statement it would help a lot! thanks The novel, the Catcher in the Rye, written by J.D. Salinger, was published in the 1940’s and became a giant hit because of it's controversial approach on teenage life. Portraying the impact that depression has in Holden’s life, the author reveals the causes of depression and how it affects his life. Depression is a big factor in the novel. It is a disorder that causes one to have feelings of guilt or worthlessness, loss of interest in activities or hobbies once pleasurable, including sex, suicidal thoughts, and one that surprises most, digestive problems. One who is depressed usually has a negative attitude towards everything. Salinger shows depression in the novel through the main character Holden Caulfield. Holden is what you get when you look up depression in the Webster dictionary. He lost a brother at a young age and has been thrown out of almost every school he has been to on numerous accounts. He feels as though he has no purpose in life, causing his lack of interest in just about everything he does on a regular basis.

• Answer:

  Write how he slowly begins spiraling down toward madness, insanity, and disconnection (not the best word) from reality and how gravely it connects with depression.