Its a trauma response, very common with depression. The only thing ive found that helps is not viewing interaction with other people as a commitment. I know im not always able to talk to others, but i dont want to push them away, so it often seems easier to just not engage in the first place. But with the right people, i know that theres no demand that i engage. Some people are just happy to be there, to know that theres someone they can talk to if they want. Basically, find a low commitment friend and if you dont want to talk, you dont have to.