Not to grill you over this but there's a common misconception that the term neurodivergent is a euphemism for autism or autism and ADHD. Its intended use was to be an umbrella term to refer to atypical brain function and mental illness: chronic depression? Neurodivergent. Acquired brain injury? Neurodivergent. PTSD? Neurodivergent.

You get the picture.

The next thing is that if you're in an abusive relationship or you've experienced a lot of abuse, it's really common to develop features of BPD. I'm not a hard skeptic of BPD - there are people who I have encountered that definitely fit that diagnosis, however I'm of the opinion that it's grossly overdiagnosed, often extremely hastily, and that it's primarily used as a wastebasket diagnosis these days. So I would gently encourage people to approach this diagnosis with healthy skepticism.

Last bit as an fyi: I know that you meant no malice by it but it's worth mentioning that the autistic self-advocacy community frowns upon categorising autism based on "severity" or "functioning" because this pathologizes people who are more unusual or who are more obvious in their autistic traits and it also conceals the fact that lots of people who appear to be very capable of expressing the "appropriate" tone, who use body language as expected, who reciprocate in communication, who navigate social interactions gracefully, and who conceal or suppress their stimming behaviour are often the people who, behind closed doors, struggle deeply with the challenges that come with being autistic. Not to make this all about me but I'm high masking, I'm reasonably smart, and I have been completely fascinated with communication and social interaction since childhood so if you met me in your day-to-day life or at a social function (depending on how much effort I'm putting in) you probably wouldn't notice that I'm autistic. Too many psychiatrists and professionals didn't see it in me either. Put me next to a solid third of the faculty at your university of choice and I'd say that you would notice more indications of autism in them than you would me. But with that said, I face significant challenges due to being autistic that can make day-to-day living extremely difficult. Also I will 100% be constantly: chewing gum, cracking my knuckles often, rubbing the tips of my fingers together or running them against certain textures, and my toe or knee will be jiggling. But because I'm not rocking in the fetal-position or flapping my hands, it isn't obvious that I'm stimming in four different ways so I'm able to socially pass. But if I spent 30 seconds flapping my hands? That's immediately going to make people think that I'm "more severe" or "lower functioning". Hence why that framing is frowned upon.

Anyway on to your actual question (finally!):

When it comes to ADHD or autism in particular, especially for late self-identifying people, there's a common trap in that you have built up all sorts of ways to compensate and suppress these traits in you and so you can fly under the radar (Goodness me! An autistic person using a metaphor!? What chicanery is this??) with respect to screening tests, formal assessments by professionals, and even to yourself.

In a clinical setting, autism is defined by three categories:

• Restricted or repetitive interests/behaviours

• Restricted or repetitive sensory behaviour

• Difficulties in social communication

The thing is though, these can be very masked, subconsciously suppressed, or the person in question may be able to compensate well for these traits. The most recent DSM revision makes specific mention of people who were socialised as girls for tending to be, essentially, high-masking and they literally call out horse girls. In what is effectively the bible for psychiatric diagnoses.

So what does all this look like in a high-masking, late self-identifying autistic person exactly?

Having particular topics or interests that you have always been preoccupied with, that you likely know to a degree of depth that is bordering on expert knowledge or which rivals expert knowledge.

That kooky aunt of yours who was a bit of a social recluse and had every single surface in their house decorated with dolphin tchotchkes? Yeah, that's very likely one of those people who went undiagnosed throughout their life.

If there's a topic that you have always been preoccupied with or which you have an unusually extensive knowledge of, even if it's just a particular TV show or the methods of producing pigment in the pre-modern era, then that's an indication. Note that you don't necessarily have to have an extensive knowledge of the topic, although it's very common to develop a knowledge base like that due to the preoccupation with the topic. Is there a particular topic that you could probably present a lecture on for an hour or more without any notes? Is there a topic which you avoid bringing up around others because you have learnt that when you start talking about it, people get bored or insulted and you risk ostracism and rejection if you talk about it so you hold back on it? Is there a topic that you hate hearing other people talk about because they completely misunderstand so much about it that it's low-key enraging for you?

Those are good indications.

With regards to restricted or repetitive behaviour, that's a tricky one. This can often look like low grade OCD or it can manifest as appearing as a bit of a control freak but it's different to both of those things.

Do you have particular ways that you do things—small processes, big procedures, anything in between—that you have a very fixed way of doing because it either feels right or it just makes sense to you to do it that way? That you feel out of sorts if you have to do it differently or change the order of things?

It often appears as having a very strong preference for doing things a certain way. You aren't going to have a mental breakdown or feel an impending sense of doom if it isn't done that way, you probably don't care if other people do it differently to you, but you have a "just so" sort of approach to things.

With regards to restricted or repetitive sensory behaviours, this generally manifests as having a strong affinity for certain sensory experiences - perhaps certain smells, almost certainly particular textures (especially regarding food), or certain ways of moving your body. (There's more to this but I'm desperately trying to salvage some shred of brevity here.) It also manifests as a strong aversions to similar things, and this is generally easier to identify - are there certain textures, such as particular fabrics, that you cannot tolerate without feeling discomfort? Are you especially sensitive to certain smells or tastes? Is there a particular food texture that you just loathe? Any particular sounds - especially high pitched squeaking, squealing, scraping or scratching sounds that set your nerves on edge?

Note that high-masking late self-identifying autistic people are usually pretty disconnected from their sensory experience and so it may take time reconnecting with your body's response to things before you realise that there's a lot of things that you are averse to but which you have trained yourself to tolerate because that's what is expected.

Last of all is difficulties in social communication. (I'm going to spare you my rant about how this is not accurate and inherently pathologises something which is atypical but not necessarily deficient.)

Social communication difficulties may present in high-masking late self-identifying autistic people as a person who is especially preoccupied with making sure that they are wording things in a "correct" way so that they aren't misunderstood, social anxiety, focusing on mirroring the emotions and body language and vocabulary of the people who you are talking to, spending a lot of effort to interpret signals and implication and body language rather than not needing to focus and to be consciously puzzling these things out when you interact with people, having a low social battery or being a serious introvert, a lot of people-pleasing behaviours, feeling like you're like a method actor when you're interacting with others rather than just being yourself - as if you're playing a role that is the stage version of yourself (or even acting out a persona that you have developed in order to fit in) instead of just being you, feeling like you are following a set of instructions or a defined pattern or a flowchart when it comes to social interaction, and often realising after the fact that you have made faux pas or you were completely oblivious to what someone else was trying to get you to understand (e.g. people showing romantic interest in you, subtle invitations, seeking reassurance, perhaps even people being backhanded or passive-aggressive).

I could go on about this for a long time, clearly. But I've rambled too much already.

So parting thoughts:

• Autism co-occuring with ADHD takes on a shape that is significantly different from either when they occur separately

• Things like mental illness and significant experience of trauma can present similarly

• Autism is something that starts at conception, so it's not something that develops later in life and so these traits should have essentially been with you throughout your life

• The ability to compensate for autistic traits often conceals them, even from the individual themselves

• It's better to focus on how difficult certain things are than to focus on how well you manage or perform in the domains above

• Not all traits are going to be applicable and they aren't necessarily going to be applicable all the time

• It's easier to assess your social functioning when you are exhausted, distressed, and when you are in novel or unexpected situations - in high masking autistic people this is where the traits tend to be much more apparent

• I haven't even touched on ADHD

Huge dong

Quick to boredom. Varied interest in different subjects depending on time or day or context, with an inability to concentrate on those same interests to the point of carelessness or agitation outside of that time/day/context. Mood swings. Apathy in general. Slow burnout that rarely recovers itself in a "reasonable" amount of time. Able to feel close to unknown people, not able to feel much connection or interest in the long-term. Bouts of isolation and/or depression. Frequently unmotivated. Forgetful. Procrastination and giving up last minute to avoid the problem. Self-medication. No respect for random people trying to "help" since I like to handle problems on my own terms, choosing treatment on my own terms. And, again specifically for me to make a point, boredom - it only goes away temporarily.

This is ADHD I guess, you can try to look closer to see if there's anything interesting or if you can figure out another diagnosis of mine - but that would be a waste of time.

Stimming often looks/feels like a involuntary tick but its less involuntary/compulsive and more just something you like to do. Lately I have been chewing my tongue as a form of stimming. I did it when I was a kid but I stopped for a long time it not sure why I started doing again but whatever.

Seemingly disjointed memory recollections. Like someone says something about a bicycle and you go off on some random story that has a bike in it but doesn't really play a big role in the story. as you learn to mask you learn to make the reference way more obvious so you don't seem so weird.

When someone is crying and venting their trauma on my shoulder and all I can think about is how nice her hair smells or I just have no reaction, even though I truly do have sympathy/empathy. For example, when my ex’s dog died, I didn’t feel anything. Part of it was because I only began dating her, but even then, I’ve cried my eyes out watching videos of people rescuing animals, sad movies and shows, but I just didn’t feel anything this time. I wanted her to feel better, but I didn’t know how. Or when I attend graduations and weddings, I just don’t feel anything.

Falling asleep when you’re bored even if you’re tired. I find myself falling asleep in church and during lectures because I have to sit still for an hour and half with no stimuli aside from listening and writing occasionally. Even on caffeine and adderall ill pass out. Though I don’t know how universal this is despite some of the docs’ claims.

I do have some other habits that make me wonder. I've wondered if I'm schizophrenic before but I only meet a few of the criteria.

I recently found out that schizoid disorder and schizophrenia are two completely different things lol. Maybe see if one or the other are more accurate to your conditions.

When Data is the most relatable Star Trek character