If they're adults, then there's not much you can do. DBT requires willingness. If you forced them in somehow (nagging incessantly maybe), they would likely shut down.

I think DBT is fantastic myself - and at the same time, you can't control the actions of others.

Plus you can "DBT them" at times. If they communicate with you, if they share problems, you don't have to say, "Well in DBT I..." - what I do is listen, hear what they're saying, and ask pointed questions. Then I gently suggest certain skills that I think would be helpful.

For example, I had a friend who was trying to deal with an interpersonal situation. She had a habit of taking on more than she could handle and in this case she had, but she'd also been given poor information. So I helped her be fair to the other person (that the other person didn't know she was overwhelmed) while also being fair to her (that she was given poor information). Then I encouraged her not to apologize for having to step away from something because she wasn't doing anything wrong, but if she felt it violated her personal code, apologizing for not being more aware of her limits would be fine. I told her to stick to her values which is that she needed to be committed to this bigger project and to be truthful about the situation she was in.

I did all of that without ever mentioning that I was walking her through the FAST skill. And it helped her. These are basic skills broken down for those of us who didn't really get them growing up. You can still pass them along without calling it DBT