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We are all born with a sinful nature. Read Peter 5:8 Be alert and of sober mind. Your enemy the devil prowls around like a roaring lion looking for someone to devour. If our nature is addictive then he can find or his demons will find that weakness and overtake us if we let him.
I believe addiction and depression are all weakness or a sickness and if the devil knows we have it, he will send his demons to try and destroy us. Remember the devil can not hear our thoughts; he is not God. Say "I am healed of addiction in the name of Jesus" and believe. In the name of Jesus, "satan be gone."
If anything is placed above Him, if it is not from Him, it is based on something not of Him. All things apart from Him are essentially evil. As difficult as they may sound, harsh even, it's true. This goes for anything. Anytime we place something or someone or even ourselves and our desires above Him, they then are derived from an unholy unrighteous place or desire. Demonic is defined in the Greek as resembling or proceeding from an evil spirit.
That being said, we must be cautious to recognize what is or where the idolatry (placing something above Him) lies. The object of the addiction itself may/is not the idolatry or evil, it is the choice to place above Him, the willful choice, that is unholy, unrighteous, evil.