(1) And the LORD said unto Moses: ‘Go in unto Pharaoh; for I have hardened his heart, and the heart of his servants, that I might show these My signs in the midst of them;
Ramban- The Holy One, blessed be He, informed Moses that it is He who has hardened their hearts in spite of their fear of Him during the hail and their confession of sin. And He explained to him: "The reason I hardened their hearts is that I'm might set in their midst these signs that I wish to do among them so that the Egyptians will know My power, but not in order that I can punish them more on account of this hardening of heart, and also that you and all Israel should recound during the coming generations the power of My deeds, and you shall know that I am the Eternal, and whatsoever I please, I do in heaven and in earth."
Orchard of Delights, Rabbi Avraham Arieh Trugman, page 222 - Depression causes people to feel alone, as if no one cares about them and in turn leads them not to care about others. This phenomenon is quite literally described in the biblical verse - "no one would could see their brother." An even more extreme form of depression occurs when people are completely sunk in the abyss and virtually unable to move. They are stuck in a state of physical or emotional paralysis. This phenomenon is also quite literally described in the biblical verse - "nor could anyone get up from his place."