Sometimes depression can just be a mystery that takes some time to uncover. While you might feel like everything is going right, you might subconsciously be dwelling on something else. It's possible that you may be stuck in the past and thinking about things that have already happened. Other triggers could include a change in environment. Moving into a senior living facility can be a stressful ordeal, so make sure you talk to your loved one about the change and try to identify any triggers of their depression.