The spirit of mammon seeks to increases the appetites of the flesh, leading to more Discontentment and Depression

And every one that was in distress, and every one that was in debt, and every one that was discontented, gathered themselves unto him; and he became a captain over them: and there were with him about four hundred men (1 Samuel 22:2).

Debt has a power behind it. Apart from creating an illusion that money and possessions will make one happy, it works through increasing the appetite of the flesh, making it one that is less and less satisfied. As it grows in greed,  envy and covetousness, one is seeks debt more, thinking more is legitimate. When one seeks more debt, one becomes less contented with what one has. This leads to depression. 

The spirit behind depression from not being satisfied with what one has is the spirit of mammon. He seeks to increase the appetites of the flesh, leading to more discontentment and depression. He seeks to murder by depression. He loves death as the wicked do.