In my life depression seems to have had two sources: loss of control (like when I was in hospital with my first baby and the neighbors took over furnishing my apartment for us to come home to ), and physical trauma (like when I had abdominal surgery, or when I broke my ankle ). With a broken collarbone keeping you from doing what you want to do and are accustomed to doing, that would probably entail both trauma and loss of control in one "swell foop". So in my lay opinion, it would be normal to be depressed. One way out, for me, would be to take back control over my life by working actively on the trauma, for instance by choosing some other activity as a work-up towards getting back on the bike.