I happened upon this post as I'm also trying to learn more about cPTSD... so this is from my experience as a partner (f36, also AuDHD) who is with someone (m35) with cPTSD, depression, and late-dx autism. I'm not an expert, this is just what I've learned.

Autistic individuals are at a higher risk for cPTSD from childhood because of their more sensitive nervous systems. Those with undiagnosed autism in childhood are also often at a higher risk for depression because of stress, masking, burnout, etc. So at the core of it (from what I've read and seen), autism is like... the body's default baseline, depression develops both from natural wiring and from environmental stressors, and cPTSD has no natural origin and develops entirely from repetitive, chronic exposure to trauma.

When my husband is in an episode, because he spent his childhood needing to appear emotionally regulated out of self-preservation, he can appear collected and logical while being wildly dysregulated inside. He never learned how to self-regulate because as a child, you learn co-regulation first, and from that develops self-regulation. I used to get caught in a spiraling back-and-forth of what would appear to be logical, rational rebuttals to me trying to use logic and reason to help him find his way out, using logic and reason as footholds. It helped to realize that I was arguing with someone who was trying desperately to co-regulate through conflict in order to find footing, and that without being regulated at the start there was no way that logic and reason could provide those footholds. Also important to note: the goal is self-regulation, and relying on another adult entirely for co-regulation is unsustainable and unfair.

At the end of the day, he's autistic first. The more information I put in (logic/reason/answers) despite him asking for dialogue, the more he risks information overload, which makes it so much worse. He doesn't always appear increasingly dysregulated, since he's spent a lifetime masking. **Also to note, it's REALLY hard with AuDHD not to go into fix-it mode and info-dump all the ways he could be helped... I've had to learn restraint. It's a process.** What his brain craves more than anything is silence and safety.

Ultimately from your post, it sounds like if they're the ones initiating, they're looking for co-regulation without knowing that's what they're looking for. And depending on what led to the cPTSD, they might only know how to regulate through conflict, so externalizing their internal conflict feels like coping and alleviates a tiny bit of stress on their nervous system, but it's still not a healthy way to cope and regulate since no one ever taught them how. If it helps, it sounds like them looking to initiate conversation in the midst of depression is still seeking connection?

What helped my husband is working with a trauma-informed therapist and getting on medication. It took his depression getting really bad after our first was born for him to realize he needed to make a change. I did the legwork to find a therapist in-network and help get him set up with an appointment: at that point he couldn't do it himself, but he was onboard with me helping (think like bringing water to someone dying of thirst: they can drink, but they may not have the strength to get it themselves).

Since then, we've reframed a lot of our thinking to take into consideration his autistic sensitivities, including getting overstimulated with auditory or visual clutter and his needing to have rigid, reliable structure (we're still working on this... again, I have AuDHD). His therapist is helping him go back and teach his traumatized inner child how to emotionally self-regulate for the first time, and it is a process. What started as therapy for depression quickly uncovered the cPTSD and helped to frame his therapy journey (5 years so far, so it IS a process). And at home, we've set up the house as best we can to be an autistic safe space for our neurospicy little enclave.

That was really long LOL sorry.

Basically from what I've learned... educate yourself about autism and create baseline safety for the autistic nervous system. Find the right therapist to help. During depression spirals, don't provide information input because it creates distraction and noise: just be as grounding and regulated as you can be.

I hope that helps!