Anecdotally: I developed a drinking problem in my first few years of work, which I used to deal with anxiety and depression as I failed to find my feet and seriously questioned dropping out of software development.

I was eventually diagnosed with ADHD (inattentive) and through treatment, experienced a complete life change.

I stopped drinking excessively, then almost completely. I never tried to address the problem directly, I just lost any desire to drink outside of a normal social context. Even then, I rarely have more than 2-3 in a night.

I'm on stimulants for treatment, but take breaks some weekends and over holidays. I've always been a coffee drinker, but now I'm conscious of how much I'm drawn to it for the positive effects I see.

I honestly think it was the only reason I got through university (before diagnosed / treated for ADHD). I was using caffeine in the same way I use my current medication, to fill the same gaps.

I don't want to comment on the effectiveness of self medication, or anything diagnosis related. I just find it interesting the correlation between certain personality types and the class of drugs they seem to be drawn to. I think it offers a lot of psychological insight we haven't really looked at in detail.

In general, it can sometimes be difficult to differentiate drug withdrawal from re-emergence of a pre-existing condition.