" It is only fair to add that you should be undecided about spiritual causes too. By this I mean that you can’t immediately say that there is one core sin that has caused your depression. Some people race toward this explanation; they hope that once they discover that sin, everything will change. Others run from this perspective; they think spiritual explanations are prehistoric and misguided. The truth is in the middle of these two poles. Sin can certainly be a cause of depression, but you must be careful about connecting the dots between the two. If you are being honest, you will always find sin in your life. Everyone does. That doesn’t mean that sin caused your depression. "
― Edward T. Welch , Depression: A Stubborn Darkness–Light for the Path