Constance’s money and privilege is exactly why I assumed she’s an addict. Imagine being so incredibly wealthy you never have to work a day in your life. Never having to particularly care about getting an education with a view to a career and money. It’s a very aimless kind of life, unless you’re very philanthropic and want to devote yourself to charity work.
Keeping this vague, but I have a relative who’s a trust fund baby (nowhere near the level of wealth than Constance) and she’s never really worked, just wafts around doing self-indulgent arty projects and trying to be an influencer. I can easily see how you fall into a serious party lifestyle when you move in monied circles and have limitless cash available.
Constance actually has a degree from a good university, then studied journalism before attending acting school (which she dropped out of after apparently falling out with a tutor, and then meeting Mark). She didn’t need to do her degree or study journalism or acting, which shows she had something about her and a wish to do something other than just party.
Everything seemed to go really wrong for her when she met Mark (she seemed to be back on track after leaving the cult a few years prior). I was surprised to see she was living in Ilford with him when they first got together (and they moved in very quickly after getting together). It’s really not a nice place and definitely not somewhere someone with her money would usually live.
To me this just shows that she was trying to get away from her background; that she may have had a mental breakdown (dropping out of acting school could indicate this); that she was most likely controlled and manipulated by him; and that drugs are likely involved.
I am not excusing her behaviour. But he is 13 years older and a convicted rapist, who was in prison for a very long time. He also seems to have isolated her from her family and friends, and was probably living off her money.