This is done willingly, which makes ADHDers great listeners and advice givers. But if this situation is unbalanced, leading to the ADHDer being always the listener, it can lead to emotional overstimulation. The more intense the relationship, the sooner this can happen.
At this point the ADHDer can disengage from their feelings. This leads to them being missing, more unhealthy hyperfocus, not answering often or as desired, and sometimes even narcissistic and uncaring. In contrast to stage 1 where they were amazing listeners, is a huge contrast.