Yes, it’s similar with ADHD as well. You really should seek a professional diagnosis before going around claiming it.
Even then you’re not free of the consequences. Sometimes just have to push yourself and say learn to bite your tongue to not blurt out an insensitive thing. What a diagnosis does give is knowing that yes it’ll be harder, to have patience with yourself, and to learn coping mechanisms.
Ironically, sometimes the worst criticism autistic or adhd people get though are from family or friends with undiagnosed autism or adhd themselves. Because they have to work so hard to mask they become very critical of people with legitimate diagnosis.
In many places getting an adult ADHD diagnosis is near impossible. I was diagnosed at age 8 personally, but I now live in a country where adult ADHD is borderline not acknowledged as even existing, and I know people have to fight very hard to get diagnosed and even harder to get access to medication if they can get it at all.
There can also be palpable downsides to having a diagnosis at all, eg in my birth country everyone with an ADHD or Asperger's diagnosis is legally required to pay for medical evaluation out of pocket to be allowed to get a driver's license and will face medical reevaluation on renewal as well.
It's not always great in the US despite it being acknowledged and somewhat accepted. It's gotta be really rough in a country that doesn't accept adhd. Ouch, a medical evaluation might make sense, but to have to pay for it out of pocket, ouch.
Though on the flipside in some countries the doctors don't care what meds they prescribe. It's very strange how things vary by coubtry. Some are absurd.
I guess my comment assumes the US where it has perhaps become a bit "trendy" as the OP suggested. I will say that when possible most ADHD'ers or aspergers do benefit from professional guidance.
Guidance definitely can be helpful. Of course it's important that the possibility exists; Ihhave high functioning AuDHD and without extra support I probably wouldn't have made it as far as I have, but there's shadow sides to "support" as well. From a very young age I had to constantly play manipulative games one way towards social workers to present myself as adequately dysfunctional to qualify for financial support that my (poor, single parent) family desperately needed, and on the other hand as more "normal" than I really was to counteract my elementary school that was convinced I should go to special education and went out of their way to contact my prospective middle/high school and try to talk them out of accepting me for instance (I ended up doing the honors track in secondary education and getting a BSc after).
I'm sure a lot of those shadow sides disappear in adulthood when one is more in control over one's own destiny but so do a lot of the benefits (eg workplace accommodations aren't nearly at the same level as school accommodations and unfortunately I'm convinced the vast majority of ADHDers/Aspies are better off not telling people at work).
It's hard to say what to make of the whole "trendy" thing, for every such person I know I know several others who are definitely on the spectrum but undiagnosed. I do think in our culture we have an unhealthy tendency to jump from "this is difficult for me" to "something is wrong with me" but on the other hand executive function or sensory difficulties are something many people experience from time to time and if "I'm a little bit autistic/ADHD" is people's best way of describing what they're going through then I don't want to silence them, because I know those difficulties are real and I have a lot of sympathy for that.
In an ideal world we'd be able to talk about the symptoms without having to reach for the syndromes, but that requires a level of experiential insight and standardized nomenclature and especially sympathy on a population level that's just not really there yet.
If you just tell people you struggle with procrastination or have analysis paralysis or get too sensorily overwhelmed by sounds or smells or the office environment to function people do still often treat each other like they're snowflake wusses that need to grit their teeth and pull their bootstraps or whatever.
The fact that this is all just part of "the human condition" often just hardens people more ("I had to grit my teeth and bear it's only fair you do the same"). Putting people in an exceptional "disease" bucket gives some respite from that, would that it be otherwise.
Better to acknowledge that there's nothing special about being diseased, there's nothing wrong with being diseased. We are all diseased and we all deserve and benefit from care. Those that don't think so should try talking to an older person ;-).
I think that part of the problem is fear of discrimination if your permanent medical record contains a diagnosis of autism. Its very conceivable that, now or in the future, a diagnosis could inhibit ones ability to immigrate, hold certain jobs, or get affordable health insurance.
Even then you’re not free of the consequences. Sometimes just have to push yourself and say learn to bite your tongue to not blurt out an insensitive thing. What a diagnosis does give is knowing that yes it’ll be harder, to have patience with yourself, and to learn coping mechanisms.
Ironically, sometimes the worst criticism autistic or adhd people get though are from family or friends with undiagnosed autism or adhd themselves. Because they have to work so hard to mask they become very critical of people with legitimate diagnosis.