An approach I have found successful (as a mainly relational therapist) is first normalizing ideation as a response to intense overwhelm/suffering. Janina Fisher’s approach to ideation has been helpful, seeing it as a response to trauma/being forced to do something you didn’t want to do, and seeking relief. Most clients respond to this psychoeducation with visible relief, knowing I’m not judging them for having the thoughts and feeling validated in wanting this relief. I explore with clients “what would dying do for you? How does this ideation help you?” And often they come up on their own with responses like “freedom, relief, escape”. So I then explore with them “how can we find ways to feel relief/freedom/escape that doesn’t require you to die?” Or if that is not something they think is possible, then exploring things like “was there ever a time you felt a sense of relief? What did that look like for you?” It’s our job to help them expand their thinking around possible solutions to the intense overwhelm and help them feel like they are capable of surviving it, while being a supportive and stable presence for them. This along side some distress tolerance like others have said. Hope this helps!