Cognitive disabilities include intellectual disability, brain injury, dementia, learning disabilities and conditions that affect attention, memory or processing. What helps across them is structure: one idea at a time, concrete words instead of abstractions, the steps in order, a pause after each one, and a summary the person can take away in writing or pictures. Explain what will happen before it happens. Check understanding by asking the person to tell you the next step, and if they cannot, break the step smaller rather than repeating it. None of this is talking down. It is the same explanation, delivered so it can be used.
Anxiety, post-traumatic stress, depression and other mental-health conditions create access needs that are often invisible and often about predictability. Not knowing what a meeting is for, being called in without warning, receiving feedback with no written record to check later, or waiting in a crowded room with no idea how long, can make it impossible for a person to think or speak well. The accommodations are usually simple: an agenda in advance, written expectations and follow-up, scheduled rather than ambush conversations, a quieter waiting option, a clear statement of what happens next. Most of them improve the process for everyone.
Communication breaks down sometimes, with anyone. The person goes quiet, or repeats a question you thought you answered, or becomes upset, or you realize you have misunderstood each other for ten minutes. The skill is repair: pause, name it without blame, change something and offer a way back in. “I think I have been going too fast. Let me stop. Would it help if I wrote this down, or if we took a few minutes?” Breakdowns become failures only when staff push through them or blame the person for them.