no here in the USA it is not a recognized mental disorder nor pathology (health problem) the phrase peter pan syndrome is slang for someone who is showing childish behaviors when they are adults.

I have a neighbor who at the age of 85 collects and plays with her dolls. instead of calling herself a collector she jokingly says shes the female version of peter pan, when she was small and everyone her age was giving up playing dress up and dolls she refused to give that up.

I know a grown adult man who loves wearing adult sized clothing articles from his childhood. he has no mental disorder, completely sane and stable he just enjoys the comforts and memories from his childhood that wearing these styles of clothnig brings him. so around the neighborhood his nick name is Peter Pan, the boy who never wants to grow up and join the present time frame.

my point anyone normal or not can be called Peter Pan and Peter Pan Syndrome if they have something that they do that is from their childhood.