does drugs is addicted. It can lead to addiction, but doing it a few times a month might not mean they are addicted. Pornography and masturbation I believe can be an addiction. As someone previously stated the hormones that are released which are similarly associated with addictions. 

I am of a personal belief that these things are more of an attempt to escape life. Pornography/masturbation are often used (atleast by those who believe it to be a sin) to escape life. I personally, am only tempted when I'm depressed, bored, lonely or need an escape of some sort; when I need a burst of dopamine. These are also instances when people would resort to drugs and alcohol.