Its a term to normalize brain damage from big pharma toxins -  eg. Vax injuries leading to ADHD, autism & behavioral disorders eg. peadaphilia.
Fairly recent, but you might find reference going back a few dacades to muddy the waters. 

 Ik I shouldn't be doing this. But ChatGPT makes tempting definitions. Start from somewhere

"Neurodiversity is a concept that recognizes and celebrates the natural variation in human brain function. It suggests that neurological differences, such as autism, ADHD, dyslexia, and others, are simply natural variations of the human brain. Advocates of neurodiversity argue that these differences should be accepted and respected, rather than being pathologized or viewed as disorders. The neurodiversity movement promotes inclusion, acceptance, and support for individuals with diverse neurological traits, emphasizing their unique strengths and perspectives" 

 I don't think it is healthy behaviour overall to euphemise disorders . 

 I put this in the same bracket as the emphemisation of overweight people . 

 *euphemisation