I remember seeing a headcanon post a bit ago concerning the Flash franchise and ADHD, specifically that Wally was diagnosed as a teenager and reading up on the condition to help him led to Barry discovering it about himself, and while the idea is good and all I actually think Wally specifically seems to me to be someone who wouldn’t have discovered he was ADHD until late in life.
I admit this comes from a place of self-projection onto favourites, but as someone who also was in my mid-twenties when I discovered it, I feel a lot of Wally’s characterisation specifically comes off as someone who’s undiagnosed.
Wally doesn’t do anything to manage the condition; he’s not taking medication, he’s rarely in therapy, and he has a lot of unhealthy coping mechanisms, from his binge-eating and preference for junk food, to his (pre-Linda) flirting and skirt-chasing behaviour.
Likewise, much of his quirks (which are actually ADHD symptoms) get light teasing from those around him (like the time Linda and Frankie teased his eating habits, or Linda and Piper before that mocking his inability to sit still during sports games, or Iris remarking how similar he is to Bart in a loving-but-teasing way), which, based on my own experience, is a very realistic reaction to undiagnosed ADHD behaviour. This would, however, make them all colossal assholes if they were aware he had ADHD and still mocked it, so for their sake, I think it makes more sense they’re as unaware as he is.
It also explains Wally’s annoyance at Bart; Bart’s clearly got ADHD too, but hasn’t got Wally’s years of self-coping so he’s way more reckless and unstable. Wally, if he knew he himself had ADHD, he’d recognise this as being why Bart is the way he is and be more patient with him, but he doesn’t, so he isn’t.
This also, sadly, is just more likely given his background and his parents. Wally is a working class kid, and, as I learnt first-hand, working class kids are far more likely to never be diagnosed. A combination of lower quality education and the costs of screening mean most working class kids with ADHD fly under the radar, as are most learning disorders, especially compared to middle class kids.
Likewise, Rudy and Mary West are definitely not the kind of parents who’d think to screen Wally for ADHD, even if it was pointed out by people who knew. Both were incredibly neglectful, with Mary being a narcissist who’d refuse to believe there was anything ‘wrong’ about her boy (since it would look bad on her), while Rudy’s outright shown to have smacked Wally for his ADHD behaviour, indicating he’d think it’s just something they could discipline out of him.
I think if anything, Barry is more likely to have been diagnosed when young given he’s shown to have a much better handle on how to handle the condition. I actually think the reverse of the aforementioned idea is more possible, that Barry recognised Wally’s ADHD because of his own, and that is what motivated him, in-part, to reach out to the kid and be a more supportive figure, because he himself knew what Wally was experiencing. He just, evidently, didn’t voice it to Iris or others (possibly because he thought it was better for Wally’s sake if he didn’t get labelled, but equally possible because Barry has a serious issue with trusting others), so when he died, so did that knowledge (and with it, the only person in Wally’s life who got what he experienced).
Continuing then with ‘every speedster has ADHD’, we then have Jesse Quick. As I surmised a bit ago myself on a thread about this, Jesse (like Barry) has clear signs of ADHD as well, but in her case it presents itself differently. This is, in-part, because ADHD presents differently between boys and girls (girls with ADHD are more likely to struggle with anxiety, aggression, low self-esteem, and being more emotional, all of which Jesse definitely has), but also because Wally and Jesse had different childhoods, particularly in how they were raised, and I feel that would have led to her being diagnosed and thus the condition presenting itself differently because she’s actively treating it.
Jesse’s childhood is like the polar opposite of Wally’s; she was middle class, which automatically makes her more likely to get a diagnoses when young, while she had parents who were overly involved in her life rather than neglectful. Johnny himself likely had ADHD too (partially because of the ‘all speedsters have ADHD’ idea, but also just…I don’t want to recap all of Johnny’s character but there’s a lot about him that seems neuroatypical too) so he’d have likely noticed and seen to it she be screened, while Libby was very focused on making sure Jesse studied as much as possible, so if she showed any signs of being distracted she’d have done what she could to find out why and fixing it.
(To be clear here, Jesse’s parents aren’t great, either; while Wally’s would have ignored the signs and let them be untreated, Jesse’s would have obsessed with trying to ‘fix’ them, which doesn’t necessarily help, especially with self-esteem)
This also gels with how Jesse and Wally’s treatment of Bart differ. Both treat Bart like a little brother, and both express annoyance, but Jesse is shown more tolerant and willing to spend time with Bart, even as he actively annoys her. Especially early on, Jesse was the one who reached out to make sure Bart was OK after Wally ‘fired’ him from the role of being the future Flash, and defended him to Wally after. The differing reactions indicate the two had differing knowledge of why Bart was the way he was; Wally just assumed Bart was like himself at that age and was just annoyed at being saddled with a kid, while Jesse recognised specifically that Bart had ADHD as well and was more lenient with her judgement of his behaviour because of it.
So, rather than Wally discovering as a kid that he had ADHD, I imagine it’s more likely something that was discovered collectively some time around Grant Morrison’s run, when the Flash Family had begun hanging out more. I’d imagine Jesse would have noticed the signs in both Wally and Bart, and most likely brought it up with Iris and Linda; Linda was shown, around this time, taking special interest in Bart, providing positive attention, giving him effective instructions, praising his efforts, and establishing rewards for good behaviour (all of the, by-the-way, are how of ADHD children are recommended to treat their kids, and is also how Barry himself likely treated Wally; that Linda was the cool aunt to Bart that Iris was to Wally is something that really needs more attention). She’d also stopped teasing Wally for his own ADHD behaviours, and Wally had, at this point, began being more healthy in how he managed them, adding credence to the idea that here is when they realised.
So, tl;dr, Barry was diagnosed as a kid, recognised the behaviour in Wally and tried to help, but never voiced it to others. When he died, Wally lost his only real effective support with it so went undiagnosed into his twenties with a lot of unhealthy behaviours, annoying those around him and butting heads with his young cousin who also had the condition. Jesse Quick by contrast was diagnosed as a young girl and raised in a household that tried to over-correct, resulting in the condition presenting itself differently, but because of it she recognised it in the boys and voiced it to Linda and Iris, and probably Jay too, leading to Wally and Bart getting better support.
