Is smoking an addiction? Is it a mental health issue?

How about overeating (thus obsesity)?

I ask because right now the UK's NHS severely limits access to healthcare for smokers and the obese.

I think the more realistic distinction between anorexia/bulimia on the one hand, and smoking/obesity on the other -if there is a distinction in NHS's "mind"- it's that the former are more sympathetic. But I dunno, I'm just guessing. I have no idea what the mandarins at NHS and similar are thinking, or, rather, will think when their resources become even more constrained than they are now. That is, I suspect they (NHS) make choices about whose healthcare to restrict... entirely on the basis of a) scarcity / need to ration, b) how sympathetic a particular target group is. How else would they (NHS) make such choices anyways? how else could they make them even remotely palatable to the polity?

We seem to be making distinctions based on some concept of free will. What happens if we view ill people as having no free will? Is it really any more wrong to deny the alcoholic high priority on the liver transplant list than to deny someone who isn't taking well to established treatments and keeps relapsing further access to treatments?

I feel like bringing up the notion of choice and free will is opening a can of black holes, but when dealing with mental illness you have to.

Yeah, I think that the mental health part confounds the issue. When it's a chronic physical illness, it's a lot easier to give someone pills to take for the rest of their life. Whereas mental health is vaguer and potentially much more expensive.

There are plenty of cancer drugs that the NHS will refuse to prescribe due to their expense. If you want them, you'll be told to go private. If mental health is so expensive, do we say the same thing?

It’s worth looking at patterns of homelessness and mass violence in the US before you take the leap. Mental illness can’t really be ignored, and untreated mental illness is dangerous for the sufferer, and the commmunity.