There are actually two questions here: Is it possible for hoarding to stop, and is it possible to make another person do something. Yes, hoarding behaviors can change. Helping clients to reduce their hoard, slow their acquisition, and develop new thinking habits to prevent recurrence are among my most common tasks. And yes, technically you (or I) could “make” someone change, but I don’t and I recommend that you don’t either. Here’s why:
Changes that are externally imposed have a much lower success rate than those that are freely chosen by the person.
Mandating change is a very serious usurping of a person’s right to autonomy. There are some situations in which taking control of a person’s choices is the right thing to do (e.g. when a person has advanced dementia and is no longer safe living alone), but these are relatively rare and require input from the person’s healthcare providers and often approval from the court. Such decisions should never be made out of anger or frustration, for someone else’s convenience, as punishment, or on impulse.
Forcing changes in behavior is not the same as forcing changes in thoughts. It is possible to make people stop hoarding–communities sometimes require it–but it is not possible, within the confines of ethical practice, to literally make them stop wanting to. To create lasting change, it is important to take the time to help the person see the value in changing and choose it freely.