If we're going to talk addiction we're going to have to talk temperaments. This, really, is the basic building block of the chart and sort of separates people into categories with particular weaknesses and strengths attached to each one. In the case of addiction, we're going to have to talk about phelgmatics in particular as water is the most difficult element to control and so have a greater propensity towards what we would call "neediness" and a focus on desire rather than responsibility. We can see this pretty well with two particular individuals.
This is Lindsay Lohan, she's been in a lot of trouble throughout her career for theft, drug possession, drinking while driving, etc. I have a bit of a hard time being sympathetic towards her, because all I can see in this chart is Jupiter in Pisces conjunct the PoF in the Second and be sextile two exalted planets.
Anyway, doing Lindsay's temperament calculation, she comes up as a phlegmatic/melancholic which means she's more driven by what she wants to do rather than what she feels like she ought to do. The fact that she idolizes Marilyn Monroe might be pretty important in an exercise of self-awareness, but I don't think Lohan quite gets it. Ultimately, people with strong phelgmatic temperament need a strong malefic to sort of keep them on the straight and narrow. Lohan isn't much strong as a phlegmatic than she is as a melancholic, and her only contender for the strong malefic title is Mars in Capricorn (which is nothing to shake a stick at), but he's pretty hosed in the 12th house and retrograde. I do, though, have hope that Lohan will turn herself around after repeated prison visits (Mars in the 12th) and I think she's done pretty well this year with not getting in trouble with the law (I think she cursed Amanda Bynes to get out of it, though). And this could very well be an example of the in-sect malefic helping its native achieve a better station in life. It sounds about like something a malefic would do.
On the other side is Janis Joplin who has a phegmatic/sanguine temperament. We can see this in the way she craved attention, feeling emotionally unfulfilled without it. There are strong phlegmatic themes throughout her teenage years when she took up painting and singing and didn't have a problem with African Americans during a time of tense race relations (one of the phlegmatic's endearing qualities is compassion) Joplin has no strong malefic in this fight and she ended up succumbing to her heroin addiction.
Just some food for thought. Phlegmatics and Melancholics typically fall into addiction easier than Sanguines and Cholerics and have a more difficult time coming out of it. Yes, these are both drug addictions, but I don't really know any sex addicts to compare it with, so I apologize if this is off topic.