Several couple interventions targeting relationship distress also show beneficial effects on individual mental health. Yet, strikingly few studies report effects on perceived stress. This study examined the effects of a brief couple intervention, the Marriage Checkup (MC), on perceived stress. We randomly assigned 231 couples to receive two MCs (Weeks 7 and 51) or to a waitlist control. Survey data were collected at seven time points over 2 years and analyzed using multilevel models. We found no significant between‐group treatment effects on average stress at any time point. However, women, but not men, in the intervention group experienced decreased stress after the second MC (d = −0.23) and more women in the intervention group (26.5%) compared with the control group (14.9%) experienced reliable improvements in stress after the second MC. Overall, the MC did not result in main effects on stress but caused temporary reliable change in terms of stress relief for women.

This study examined maintenance and booster effects of a brief couple intervention, the Marriage Checkup (MC), across 5 years. A subsample of 63 couples who benefitted from two previous MCs (responder couples), were randomly assigned to a third MC or control. Before randomization (at 4-years-9-months), the responder sample had maintained small to medium effects on two measures of relationship functioning. After randomization, we found no significant between-group effects. Yet, within-group analyses revealed that while control couples showed flat trajectories in all outcomes after the 4-year-9-months baseline, couples receiving a third MC (at Year 5) reported small to medium improvements in three measures of relationship functioning and maintained follow-up effect in one measure. Findings indicate that couples who initially improved from the MC can maintain some of their improvements over long periods. The potential of boosting such improvements with recurrent MCs is a