Well there’s alcoholic and functional alcoholic. There are actually functional heroin users too, but it’s taboo to mention it because one hit and you’re dead according to the media.
You could use a similar comparison for suffering in general (chronic illness, chronic pain, etc.) Some may appear more functional than others while in such conditions. Just because you're functional with chronic pain, doesn't mean you aren't hurting and that your life would be very different without that suffering.
Edit: Spelling