When a young person presents with both addiction and failure to launch, there is almost always a pressured tension between the patient and his or her family, especially those who control the pursestrings and pay for the therapy. The twenty-something’s journey (out of addiction and deferral, and into adulthood) should be distinct from his relational process with his family. In fact, it may even be psychologically necessary for him to move forward without having reached a stable accord with them. That way, he can be sure that his progress is not mere compliance. As that progress yield concrete results---especially, paying more of his own bills---he can be more confident that it isn't mere defiance, either.
Compliance and defiance typically have been the poles between which the patient has been running back and forth for years, inside a family system which is stuck in that pattern. His compliance seems to be movement forward into adulthood, so long as most of what he complies with happens to be good advice, and reasonable rules, that come from exasperated elders who may well love him. But compliance is never really as good as it looks, because it's not autonomous, so it is not sustainable; it builds resentment that comes out sooner or later. His defiance appears to be much worse, of course, because it's often full of hostility, self-destructive, anti-social, risky, and debilitating.
Part of the reason this pattern is so terribly stable and hard to break up, is that the family's response to the young addict's defiance is usually a call for a return to compliance, this time a new-and-improved compliance that will last. That never works, because even if he does produce a good lengthy chunk of compliance, it's still mere compliance. The solution is, in most such cases, to bring in a therapist whose client is not the family, but the patient himself. That way, the patient can continue doing the only two things he knows how to do, but in a whole new way which will permit him to learn new skills: he defies the family, and complies with the therapist in a genuine, collaborative search for what the patient (himself/herself/theirself) actually wants from life.
Why is that compliance somehow better? Well, between the patient and the therapist there is no personal history of being hurt, or betrayed, or robbed, or worried half to death. The professional is not burdened with guilt or regret about the past of the patient and his family. So she or he can afford to keep the patient's interests central, striving to collaborate with him on a viable path to a good-enough life (good-enough in the patient's own terms), at the heart of which must be a kind of guarded friendship between the struggling young patient and Reality.
This is the same Reality which he has avoided for so long, languishing in addiction and the related un(der)employment. For him, Reality has been a place of failure, shame, and fear. Changing that is not easy, even with professional help. By the time such a patient arrives in the therapy office, he may have been to rehab, only once or many times. Depending on the nature of the addiction involved, recovery might be the first order of business; sometimes it has to come second or third. The choice (or the cycle) between abstinence and harm reduction should be respected, in accord with the specifics of the case and the values of both patient and therapist.
When something has been stable---even something toxic and annoyingly stable, such as a particular dynamic in a family system; a particular role for a particular person; any ongoing relational process that's been around for a while, even if it's one that truly sucks---its replacement by something better is still a big change. And all big changes, good or bad, are losses of the familiar. The good big changes are also gains, sometimes far bigger gains than the loss involved. So when a young person is coping with addiction and "failure to launch," and he or she manages to change and become successful-enough, sometimes the family gets upset---even though this good development is exactly what they've been pulling for all those years. It's new and it feels strange and people aren't sure how to respond to it.
And from the patient's side, as the therapy gains traction his capacity to manage his own affairs may be growing at a different rate than his capacity to deal with his family in ways that remain timely, kind, and effective for the pursuit of his own interest. Again: the patient's ability to cope with reality may be growing somewhat faster than his ability to deal with parents or other attachment figures in good-enough ways, enough of the time. Those older adults should try to keep these two capacities distinct in their minds, even though they are closely linked. Yes indeed, a guy who can keep a job ought to have the relational skills to manage his family elders without too much emotional noise-making. But as a therapist I can report it's extremely common for people of all ages to regress into childhood self-states when they deal with their parents---especially when purse strings are involved; or when there has been a divorce; or when there has been bereavement in the early death of a parent; and when addiction has been the main coping mechanism for a long time. If the patient acts messy with his folks, it doesn't necessarily mean he's still being messy out in the world.
In general, as far as good things go---things that might flow from the family to the patient, in recognition of his recent achievements---timing is important. It may be fine, and even lovely, for his family to use words and gifts to celebrate him for going straight after he manages to do so. But such things should never be mentioned beforehand, nor set up as an incentive. It has to be a free gift, at the right time, not too soon and without any strings attached. Of course, when therapy has just begun and addiction is still active, that's still a distant concern.
Compliance and defiance look and feel very different. Ultimately, both are forms of captivity to the cycle they form together. The way out is a genuine alliance between patient and therapist, in which it's made clear that there is a world---vital, interesting, unpredictable, sometimes friendly, and not impossible to join---beyond the one that has proven so painful and boring. Sometimes, the first hint of this lies with something outside the problem which can illuminate it: literature, or religion, or science and nature, or politics---it doesn't matter what the source is, so long as the patient gets the news (eventually, and as soon as possible) that, as Shakespeare's Coriolanus says when he leaves his mother: There is a world elsewhere.