What I stated, "In doing so, the chronic pain sufferer will be able to recognize the depression as not sinful in itself, but manifesting attributes of sin such as anger, self centeredness, selfishness, and unbridled tongue. Other manifestations may also occur."
There is no scripture that states, "Thou shalt not be depressed."
Many of the characters in the Scriptures went through depression and depressing times, some like Elijah, ran and hid then bemoaned.
Did Elijah sin? If he did, there isn't any account of his confession.
Can the manifestations of being depressed result in sin? Yes. The same as wrath and anger in them self is not a sin, but the unbridled tongue spewing blasphemies is a sin.
James made the same distinction when talking of lust.
Jas 1:13 - 16
Let no man say when he is tempted, I am tempted of God: for God cannot be tempted with evil, neither tempts he any man: But every man is tempted, when he is drawn away of his own lust, and enticed. Then when lust hath conceived, it brings forth sin: and sin, when it is finished, brings forth death. Do not err, my beloved brethren.
It is the same with every elemental condition of human kind.