The woman who created ASPECTSS has done some significant follow-up work and my opinion is that her findings are robust, but I also haven’t found much that has really direct measures like “productivity increased 10%”.
Sensory processing and overload is one of the areas I think design could help with a lot. Depending on at what stage you’re working from, there’s a whole lot a designer can do with acoustics, light, and zoning to mean that you only have to pay attention to a limited number of things at a time.
I’m an anthropologist by trade, not an designer (that’s my sister). So, my interest is in the relationship between behaviour and space. From my research, I think that unlike some kinds of issues, it doesn’t take special knowledge within the standard scope of interior design to design for ADHD… that is, anyone who has the knowledge to design for neurotypical people also has the knowledge they need to for ADHD. But what is missing, potentially for both the client and the designer, is knowing what to ask for. The designer may not realize to ask about sensory stuff, or to investigate memory issues and whether the space supports the person’s routines and that sort of thing. Meanwhile the person that wants their space to work better may not know what it is possible to ask for, or even how to articulate what’s wrong. So that’s the sort of intellectual space that I think needs work.
From that bigger picture, I find it kind of frustrating that so much of what’s out there is focused on “calming colours” or whatnot. Colours do impact how we feel, but it’s only one part of what a design does for our mental state.