The two most common forms of therapy for people suffering from shared delusional disorder are personal and family therapy.
Personal therapy is one-on-one counseling that focuses on building a relationship between the counselor and the patient and aims to create a positive environment where the patient feels that they can speak freely and truthfully. This is advantageous because the counselor can usually get more information out of the patient to get a better idea of how to help them if that patient feels safe and trusts them. Additionally if the patient trusts what the counsellor says disproving the delusion will be easier.
Family therapy is a technique in which the entire family comes into therapy together to work on their relationships and to find ways to eliminate the delusion within the family dynamic. For example, if someone’s sister is the inducer the family will have to get involved to ensure the two stay apart and to sort out how the family dynamic will work around that. The more support a patient has the more likely they are to recover, especially since SDD usually occurs because of social isolation.