I have diagnosed:
Asperger's Syndrome, ADHD, anxiety disorder (not particularly specified, but not sure if it would be NOS), depression which has been diagnosed as both major depressive disorder and depressive disorder-NOS.
I have undiagnosed:
A chronic pain condition that may be fibromyalgia.
If you combine all my comorbids, then yes, they do cause me more difficulty. Individually, I don't know. I spend a lot of my time trying to map out the consequences and symptoms of each condition. Some things overlap in ways that can make it difficult, though.
Specific things I know:
* I managed to fail to pick up a lot of common life skills (activities of daily living) without realizing it. I understand this is common on the autistic spectrum. A basic skill I missed is knowing how to ask for help, although I am better about it now. Not knowing that has caused me a lot of trouble over my life.
* Even with the skills I do have, it's hard to shift my focus to doing anything with them. I think both autism and ADHD can cause this, but I think the weight of this goes to ADHD. Fibromyalgia can also impact concentration, focus, and other related things, making executive function all the more difficult.
* AS, ADHD, and fibromyalgia can cause sensory problems. I don't know how severe my problems are (but have been told they sound moderately bad), but having two conditions that typically cause sensory sensitivities and overload, and a third that has a good chance of doing so...well, I don't think they stack in a linear fashion so much as it just makes it pretty certain.
* I have spent a ton of energy building coping mechanisms and maintaining them: Managing my suicidal ideation, defusing anxiety before it became severe, defusing panic attacks before they became severe, ignoring and working around pain, trying to sustain social facades for interacting with other people, trying to keep track of the things I should and should not say in social situations, ignoring and working around sensory overload. It's pretty exhausting to try to focus so much cognitive effort on just trying to function around disabling conditions. I'm not even sure if I managed to build up any coping mechanisms for my ADHD. As far as I can tell it responds to medication and little else. Or it may be I just don't have the cognitive bandwidth to spare for that on top of everything else.
One of the effects of learning that I have these conditions is that I've noticed the things I was ignoring or holding back, and once I noticed them and acknowledged they were there and real, it became harder to maintain mechanisms. The pain is more noticeable all the time. The sensory overload is harder to get around and a lot of things I used to do are more difficult because I am more aware of the impact of doing them. I let go of my social facades, although not so much my "social scripts." Not sure I could let go of those.
One of the biggest barriers I've had to getting work is that I can't interview. That is, I have never been hired for a job that I've interviewed for. This has had a pretty big impact on my ability to support myself. Admittedly, all kinds of other factors play a role once I have a job, although I think primarily AS and ADHD have made it difficult for me to hold jobs (or stay in school). Medicating my ADHD made it possible to stay longer, but I still ultimately burned out.
So I don't know. I don't think it's so fuzzy that it's impossible to tell where one ends and the other begins. I do think that each plays off the other to make things harder than they need to be. Trying to manage a lot of pain makes it much harder for me to focus on filtering my social responses, for example. And for whatever reason, whichever combination of factors, sometimes just opening a can of food and microwaving it feels far too complex, let alone actually cooking food on a stove or in an oven.
So, I don't really know which one is more impairing. Considering I spent most of my life not even knowing some of them were there - and the pain only came into the picture 7-9 years ago (during my burnout ), I'm still working out the impact.