I recently published a trilogy of works which could broadly be subsumed under verbal aikido/de-escalation of aggression. There are two versions: one for social services professionals (not necessarily clinical interventions - most of the info is equally applicable to someone who works in everything from the medical field to a homeless shelter or soup kitchen and the second version of the trilogy is for families who live with an aggressive or mentally ill family member.
I will say that the majority of the information in the books is universally applicable, not just for social services people - particularly the professional version of Centering and about 2/3 of the info in Grace Under Fire