Do you consider that pathological lying is a mental health condition? This syndrome intrigues me because someone who is pathologically lying has no benefit from the lie. What could cause this condition?
https://www.medicalnewstoday.com/articles/pathological-liars#causes
https://www.webmd.com/mental-health/what-to-know-pathological-liars
I think that pathological lying is more often a symptom of a mental health condition, rather than being its own condition.