Yeah, that sounds like it might be worth a shot then.

I don't know what the nature or cause of your intrusive thoughts are but I have PTSD and clonidine pretty much stops me from having PTSD nightmares and it's sorta like having a ceiling to my trauma responses - I still feel things like anxiety during the day and things can still trigger me but instead of it being a situation where I'm completely and entirely subsumed by a runaway trauma response which I then have to wrench back around to gradually calm myself down after its gotten away under its own momentum, with clonidine I find that I will get a bit panicked or whatever but my brain and body aren't in a full blown life-or-death response and so my strategies for managing myself are much more effective and it's a lot less work to handle that stuff. I know that PTSD isn't the same thing as having difficultly with intrusive thoughts but there are a lot of parallels, especially when we're talking about how the brain produces and responds to these phenomena.

It's also worth noting that Rejection Sensitive Dysphoria is pretty common in ADHDers, speaking anecdotally from reports within the community because it's basically ignored in the literature, and so if some of those intrusive thoughts kick off an RSD response in you then clonidine is probably gonna be a good fit.

This is probably going to sound dumb as an analogy but I felt like my brain and my entire nervous system was like an untamed horse - it was just so quick to bolt or panic or to lash out in self defence and I had very little control over it. I basically just held on for dear life and waited until it exhausted itself before I'd be able to regain some degree of control over it. With clonidine I find it's like a tamed horse - I still get nervous and I can get spooked but I'm much more capable of reigning that sort of stuff in with comparatively little effort, I'm much more responsive to management strategies, and I don't require hours/days to settle back down to my baseline.

For whatever it's worth, on a neurochemical level this tracks because clonidine has shown to reduce impulsivity (and associated behavioural/emotional responses) and if we look at it as if impulsivity is the nervous system being unable to regulate itself effectively then, in theory, that reduction in impulsivity means that clonidine is acting to help regulate the nervous system. I could go on for ages about this but I'll bore you to tears if I do lol.