"Fear is the most obvious co-conspirator with depression; anger is the most common. The formula is a simple one: Sadness + Anger = Depression" Depression A Stubborn Darkness, Edward T. Welch, page 153
"Anger will not always be the cause of your depression, although some researchers want to tell you that it is a likely cause. But anger is frequently revealed by depression. The wisest way to approach this subject is to assume you are angry." Welch, page 154
If I blog much at all in the next few months the topic will be on Anger.