ADHD vs Alcoholism, and enabling

Being in a relationship with someone with untreated ADHD has been compared to being in a relationship with an alcoholic, where the non-addict spouse almost inevitably becomes somewhat codependent. The codependent non-addict spouse falls into a pattern of "enabling" the addict by rescuing them, by cleaning up after them, by picking up the slack etc.  Because of this enabling behavior the addict doesn't have to face the consequences of his own actions, and therefore is never motivated to change his behavior. 

The obvious difference between an alcoholic or drug addict and a person with untreated ADHD is that one is an addiction to a substance, whereas ADHD is a a behavioral/mental issue. 

I have recently become separated from my ADHD husband, his idea not mine.  I am learning more about codependency and I'm actually feeling quite guilty for enabling him, and also for the nagging and criticism. I'm feeling guilty for the possibility that I was preventing him from helping himself. 

 So my question is: do you think a person with ADHD can improve on their own when there is no one to clean up after them, or not?  (In other words, how much am I responsible for his continuing/worsening ADHD symptoms?)

Interested in hearing your thoughts!