What this Trial Is About

Considering the high prevalence of couple distress in Western countries and rising divorce rates, there is a pressing need for accessible and evidence-supported interventions that can strengthen relationship functioning. Although mindfulness has been positively linked to relationship functioning, only few studies have investigated the effects of mindfulness interventions specifically targeted at couples. However, these studies suffer from methodological limitations such as lack of an active control group. To address this gap, a feasibility trial with progression to a full-scale randomized controlled trial (RCT) will be conducted, depending on whether stoppage criteria are met, to evaluate the effectiveness of a Mindfulness-Based Couple Intervention (MBCI) compared to an online active control intervention (Self-expansion Intervention) and waitlist control group. Moreover, consolidation of intervention effects is examined up to 6 months post-intervention. Finally, possible working mechanisms and the effect of potential moderators are examined. The current study has three arms: (i) MBCI, (ii) active control intervention (i.e., a self-expansion program) and (iii) waitlist control, with assessments at baseline (T0), immediately post-intervention (T1) and at 6 months post-intervention (T2). After the follow-up assessments, waitlisted participants are offered to take part in (an online version of) either the MBCI or the active control intervention. The study aims to include 213 couples (426 participants, age \>20 years) with a minimum relationship duration of 2 years. Couples will be randomly assigned with a 3:3:2 ratio to MBCI, Self-expansion or waitlist, respectively (with a total of 80 couples in the intervention groups and 53 couples in the waitlist control group). This is a multi-site RCT, with five different centers spread across the Netherlands, based in Nijmegen, Tilburg, Amsterdam, Maastricht and Groningen. In the feasibility phase, 42 eligible couples will be recruited from two sites (Nijmegen and Tilburg). Stratified variable block randomization will be used(block sizes of 8 and 16), with study site as stratification factor. The MBCI is a close adaptation of the widely used and well-researched Mindfulness-Based Stress Reduction program (MBSR), developed by our research team. Couples learn how to practice mindfulness meditation and how to apply mindfulness in their daily life and in their relationship. As compared to the MBSR, it includes adapted and additional exercises to practice mindfulness within the relationships, such as mindful communication exercises, mindful touch, and mindfully viewing one's partner. The active control intervention encourages couples to invest in self-expansion, by doing a novel activity together every week. This intervention is based on self-expansion theory. According to this theory, couples are satisfied with their relationship as long as they experience a sense of self-expansion. A sense of self-expansion can be promoted by engaging in novel activities together and gaining new insights from each other. Both the mindfulness- and self-expansion interventions consist of 8 weekly sessions, plus a silent day (for MBCI) or a day out (for the self-expansion intervention). Interventions are similar in non-specific factors such as format, structure, time commitment, teacher support, and group dynamics. The primary outcome is to compare self-reported relationship satisfaction as measured by the Couple Satisfaction Index (CSI-4) from pre-intervention (T0) to immediately post-intervention (T1) between the MBCI group compared to the active control group and between the MBCI group compared to the waitlist control group. Secondary outcomes include the difference in relationship satisfaction from pre-intervention (T0) to 6 month post-intervention (T2) between participants in the MBCI compared to the active and waitlist control group, as well as differences between participants in the MBCI compared to the active and waitlist control group in various relationship behaviors, perceptions of the partner, and individual outcomes measured from pre-intervention (T0) to immediately post-intervention (T1) and pre-intervention (T0) to 6 months post-intervention (T2). In addition, a number of potential moderators, including commitment, attachment style and trait mindfulness measured at T0 will be assessed to determine for whom these programs work. Unless the trial team determines, based on stoppage criteria, that trial procedures need important modifications thereby re-setting the full-scale trial as a new trial, the outcome data of the participants in the feasibility portion will be utilized in the analyses of the full-scale trial.

Mindfulness in Couples