Thanks to the stability and the emotional involvement that they imply, couple relationships represent an ideal context where the partners can test their respective pathogenic beliefs (Zeitlin, 1991). The aim of this work is to present a method for the assessment of couples according to Control Mastery Theory (CMT) and its implementation to one married couple and one parental couple. The first couple wanted to improve their communication skills while second is a high-conflict couple (Carter, 2011) that needed a support of co-parenting. The procedure we followed consists of: (1) a couple session; (2) one or two individual sessions oriented to the Plan Formulation Method; (3) another couple session aimed at talking about what emerged during the assessment and about the specific treatment proposed to them. The tools used for the plan formulation are: the Interpersonal Guilt Questionnaire-67 (IGQ-67, O'Connor et al, 1997), the Interpersonal Guilt Rating Scale-15 (IGRS-15, Gazzillo et al., 2017) and the Pathogenic / Problematic Beliefs Scale (PBS; Silberschatz, 2016), both in their clinician and self-report forms, and the Shedler Westen Assessment Procedure-200 (SWAP-200, Shedler, Westen, Lingiardi, 2014). In both cases, the pilot study shows that factors such as the personality, beliefs, guilt, and partners’ attitudes provide information useful to understand the functioning of the couple or co-parents and for planning a case-specific treatment. Moreover, if the partners can observe directly and clearly the circular dynamics powered by the contributions of each of them, it is possible to develop a greater awareness of dysfunctional dynamics and a stronger motivation to the intervention. Future studies are needed to increase our sample in order to evaluate the reliability and validity of this method, correlating the procedure with the assessment of the process and outcome of the treatment
