ADHD = attention deficit hyperactivity disorder, which really ought to be called something like attention prioritization disorder. It's a mostly-inherited brain difference (50,000 years ago, it was the dominant neurotype) in which the parts of the brain responsible for handling dopamine are underdeveloped, forcing you to constantly look around for stimulus to produce it.

This is incredibly useful if you're a prehistoric hunter scanning the savannah for threats, but a severe disability if you work in a factory, because either too few (no dopamine) or too many sensory inputs (overwhelm) can cause a state of psychological paralysis ("lazy").

OCD = obsessive-compulsive disorder

GAD = generalised anxiety disorder

MDD = major depressive disorder

PTSD = post-traumatic stress disorder

Most of the above can be caused by social reactions by neurotypical people to people with ADHD and autism - by the age of 12, you will have typically received 20,000 more negative messages than neurotypical children ("sit still", "why are you so weird?") - which also commonly leads to two more compound-PTSD-related acryonyms:

RSD: rejection sensitivity dysphoria = "please don't reject me again, I'll do anything!"

ODD: opposition defiant disorder = "if nothing I do is good enough, then why bother?"