“…Lastly, when focusing on the therapist's role, studies on the effects of their training on treatment responses are still lacking systematization (Beutler et al, 2004), with the result of jeopardizing the quality of research findings and concluding that this variable does not make a difference (Mahrer, 1999) or, when it does, such difference is mediated by other variables (e.g., interpersonal skills irrespective of years of experience in clinical practice; Stein & Lambert, 1984). On the contrary, it is quite indubitable that even experienced clinicians might engage in destructive and dysfunctional dynamics (e.g., Accordini, Browning, Gennari, McCarthy, & Margola, 2017;Ackerman & Hilsenroth, 2001), especially when patients are characterized by negative or ambivalent IPIRs, overall hostility, early negative responses to treatment, and, more in general, low levels of interpersonal complementarity (e.g., Henry, Schacht, & Strupp, 1986;Henry et al, 1990;Lambert & Ogles, 2004;Orlinsky et al, 2004;Tanzilli, Muzi, Ronningstam, & Lingiardi, 2017;von der Lippe et al, 2008).…”