Through therapy and research/ reading, there are behaviours where Autistic/ADHD people may seem to be engaging in narcissistic like behaviour but it is not that.
The difference is ALL in INTENT. For some people who are ND, the intent is not to control, hurt, etc. Instead, behaviour that might seem gaslighting for example could be based in communication differences or interpretation, being brutally truthful and honest without wanting to harm.
With nsrcs and sociopaths, it is to hurt and control. With narcs, it's to deflect from inner shame and low self esteem, usually accompanied by absent empathy.
You can be ND and personality disordered, as much as an NT person would be personality disordered. One might see the risk of developing a personality disorder as greater in ND people who often do suffer alot of trauma and attachment struggles in this world.
I struggle to discern with my autistic teen son what is his ND state and what are inklings towards personality disorder type stuff. Had every card stacked against him to be fair.
Narcissism and sociopathy are not the same.
Sociopathy is further along the scale in terms of danger and potential harm. Apparently narcs have a greater need for validation and alot of behaviour is based in insecurity. It's slightly darker with sociopathy. A greater inclination towards violence to others and giving no shits.
I believe all sociopathic and psychopathic people are also narcissistic. But not all narcs are sociopathic or psychopaths.
In terms of a traffic light scale it would be
green ( mouldy green at that) - narcissist
amber - sociopath
red ( run for your bloody life) - psychopath