Neuroatypical refers to people whose neurological structure or function doesn't fit what the medical community defines as "normal".

Neuroatypical people could be on the Autism Spectrum, on the schizophrenia spectrum, have bipolar disorder, have ADHD, or other non-neurotypical conditions.

A synonymous term is neurodivergent and an antonym is neurotypical. A group of people whose neuro types are varied is neurodiverse.
All of the above terminology were coined by the Autistic community.

When a person is not neurotypical (a term coined by the Autistic community, used to describe someone with a 'normal' brain). Neuroatypical is used to describe people who have bipolar disorder, ADHD, schizophrenia, circadian rhythm disorders, developmental speech disorders, Parkinson's disease, dyslexia, and dyspraxia.