The only reason why people are addicted is because they place more value on the substance or behaviour that they are addicted to than they place value on God however, that does not mean that everyone who has an addiction is unsaved.
Please understand, by no means does salvation give us a license to sin. I believe it's just the opposite. Yes, it is quite possible that many who are indeed enslaved by sin have religion instead of real salvation. However, I believe that there are many who are indeed saved who are truly repentant however, they simply do not know how to obtain victory. They do love God but because of little or poor discipleship, they remain enslaved by something.
I have found this to be true particularly among newer believers, ussually after the first six to twelve months after their initial salvation experience once the newness (zeal) has worn off. These people need (1) to experience God's love on such a deeper level than they no longer place more value on sin and self, placing more value on God and His precious promises, and (2) they need to be taught the depth of God's love for us and how there is victory from sin when we walk in His love.
Ephesians 5
Walk in Love
1 Therefore be imitators of God as dear children. 2 And walk in love, as Christ also has loved us and given Himself for us, an offering and a sacrifice to God for a sweet-smelling aroma.
3 But fornication and all uncleanness or covetousness, let it not even be named among you, as is fitting for saints; 4 neither filthiness, nor foolish talking, nor coarse jesting, which are not fitting, but rather giving of thanks. 5 For this you know, that no fornicator, unclean person, nor covetous man, who is an idolater, has any inheritance in the kingdom of Christ and God. 6 Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience. 7 Therefore do not be partakers with them.Walk in Light
8 For you were once darkness, but now you are light in the Lord. Walk as children of light 9 (for the fruit of the Spirit is in all goodness, righteousness, and truth), 10 finding out what is acceptable to the Lord. 11 And have no fellowship with the unfruitful works of darkness, but rather expose them. 12 For it is shameful even to speak of those things which are done by them in secret. 13 But all things that are exposed are made manifest by the light, for whatever makes manifest is light. 14 Therefore He says:
“ Awake, you who sleep,
Arise from the dead,
And Christ will give you light.”