People are too keen to diagnose themselves with conditions that are no laughing matter for those who really have them. "I'm a bit Asperger's" (I pay attention to detail) "It's my OCD..." (I like things to be tidy) "I'm a depressive" (When things aren't going well, I feel a bit glum) and so on.
I have friends whose lives have been made incredibly difficult by having real Asperger's, real OCD, and real depression. Strangely, a mental health issue or neurodivergence has acquired some sort of cachet, at least amongst those who are looking for a way to present themselves as "special".
We should not make an arbitrary decision that the top or bottom 5% of any bell curve is a "syndrome". In my view, it is only a syndrome if the bell curve goes back up again briefly, like a little foothill at the side of the main hill, and if this happens over 2 or more related metrics.
Narcissistic Personality Disorder is a pretty serious condition which can affect the subject and those around them. Simple old fashioned Narcissism has always been a part of society.
However, the advent of the mobile phone, the selfie, and the instant gratification available through social media, have made overt narcissism more widespread, and more socially acceptable in one part of society.
A few years ago, I looked up a work colleague on Facebook. We got on OK at work, we had helped each other out with difficult cases a couple of times, and I was thinking of making overtures of friendship (nothing more). She was 30-something, well qualified, with a decent job, but when I looked at her FB feed, it was selfie after selfie: over 100 virtually identical pictures of her pouting at the camera trying to approximate the Platonic ideal the Selfie Form. I did not click the button.
It is perfectly possible to use social media more constructively — we are doing so in this forum — but what a shallow attitude to life it can encourage.