Marianne Welmers

Chapter 6 144 both on the process of alliance over the course of treatment (Chapter 4; Bhati, 2014), as well as its relation to treatment outcome (meta-analysis on alliance change and outcome in Chapter 2; Friedlander et al., 2019; Johnson et al., 2002). Given the fact that in many cases ideally both genders are present in systemic family treatment, more knowledge on gender-specific aspects of the alliance is warranted. Working on Multiple Alliances: Systemic Considerations Another important strength of this dissertation, is that it was – to my knowledge – the first to investigate systemic aspects of the alliance in the field of HBFT, providing more knowledge on the complexity of buildingmultiple interacting alliances bothwith andwithin the family system. These findings add to a relatively small, but emerging body of research on systemic aspects of the alliance in family treatment, and warrant further research for several reasons. First, the sample of families providing sufficient data to investigate the association between systemic aspects of the alliance and treatment outcome was small (Chapter 5), resulting in limited statistical power and hindering the use of preferred methods to investigate the effect of unbalanced alliances (e.g., polynomial regression; Bartle-Haring et al., 2012; Laird & De Los Reyes, 2013). Building on this explorative study, further investigation of the effect of unbalanced alliances and the family’s shared sense of purpose on family treatment outcome is important, andmay benefit from studying larger samples with a multi-informant perspective on the family’s shared sense of purpose. Second, in the study on therapist contributions to the alliance (Chapter 3), therapists’ contributions to the family’s shared sense of purpose were excluded from the analyses: therapists’ scarce observed investment in SSP complicated the establishment of sufficient interrater reliability for this measure. Given previous studies’ indications of the importance of systemic alliance aspects, such as family members’ sense of safety and their shared sense purpose (Friedlander et al., 2018), the finding that therapists scarcely invest in these systemic aspects of the alliance raises the question for future research on how therapists can be trained and supervised effectively in using skills to enhance alliances in systemic treatment. Third, although the current dissertation did measure therapists’ safety contributions, it lacks a reliable measure of family members’ sense of safety within the treatment context. The importance of family members experiencing the conjoint treatment context as a safe environment is indicated by two previous studies (Friedlander et al., 2008b; Sotero et al., 2018), and may perhaps be of extra importance in home-based family treatment, as the therapist ‘invades’ the family’s home environment. However, no studies on alliance including family members’ sense of safety in the context of home-based family treatment – to my knowledge – have been carried out so far, indicating an important direction for future research.