There is no rule about having to work with both partners if one partner is disinterested and the other wants assistance. In fact, addressing relationship issues within Individual counseling is not out of the ordinary.
This question is similar to the one above; there is no rule about having to work with all the family members if someone is unable to participate for one reason or another. Depending on the situation, we could possibly put aside an empty chair to “bring” the person into the room.
I have worked with parents of adolescents or adult children who received chemical dependency treatment or were still actively using substances. The challenges for parents of both age groups are similar yet very different; they are different even for parents of younger versus older adolescents.
Need is typically the determining factor along with financial ability. It is not uncommon for Individuals to meet weekly whereas Couples/Families may start weekly and then taper down with less frequent visits.
It is your legal right to end your work with me at any point in the process. As a rule, I encourage folks to talk about their intentions in advance of taking action. Sometimes an impulse to leave is just that, an impulse to avoid what might be an opportunity for growth.