To our knowledge, no other large-scale studies have included a large number of risk factors for emotional distress in couples. The current population based sample with 62,956 spouses gives a statistical power which permits the detection of even trivial main effects and even moderately high interaction effects.
The first aim of our study was is to investigate the relative contribution of a selection of well-known risk factors for emotional distress in 62,956 Norwegian couples. As expected, the 12 predictors included in the analyses all had significant unique effects on women's emotional distress. For men, 9 out of 12 factors had significant unique effects. Relationship dissatisfaction was the strongest predictor for both men and women, and this predictor explained 7.8% of the total variance (in terms of squared adjusted β's) in women and 5.3% of the total variance in men. This finding is in accordance with our hypothesis that relationship satisfaction is of special importance for both genders. Somatic disease, unemployment, and first-time motherhood were also among the strongest predictors for both sexes. Cross-spousal effects were generally weak. The spouse's self-esteem yielded the strongest effect on women's emotional distress, while the spouse's relationship satisfaction was most important for men.
The most important aim was to explore to what extent high levels of relationship satisfaction, perceived both by the individual and the partner, could buffer against adverse psychological effects of certain strains. The results indicated that a subjective feeling of having a good relationship with a partner may protect against the effects of most types of stressors. If the spouse experiences high relationship satisfaction, this may also act as a buffer against certain strains, and whereas the main effect of spousal relationship satisfaction was weak, the buffering effect was remarkably strong. These results are in accordance with our second hypothesis.
Level of relationship satisfaction in couples
The alpha reliability on the RS scale was 0.90 for women and 0.91 for men. The "true" partner correlation, corrected for imperfect reliability, is 0.55/(0.910.5
) = 0.60, reflecting strong agreement in perceived partnership quality. The majority of the participants in this study were satisfied with their relationship. Most couples plan to have children when their relationship is good and life circumstances such as work and housing feel safe and stable [62
]. Under these circumstances, pregnancy is a happy experience associated with positive expectations for most couples. The literature shows a decline in marital satisfaction after pregnancy [63
], which is what to expect of the time when expecting a child is among the happiest periods in many couples' lives. Also a possible decline could be caused by stress associated with giving birth or with the transition to parenthood.
The low-satisfaction group consisted of slightly more women than men (3.4% versus 2.6%) but the mean values were approximately the same (5.36, SD = 0.60 and 5.35, SD = 0.56). Several studies have found at least some differences in perceived marital quality, typically with women reporting lower levels of self-reported marital quality than men [65
]. Other studies have found an overall absence of gender differences in marital quality [67
The effect of relationship satisfaction on emotional distress
As expected, emotional distress was more strongly influenced by personal variables than partner variables for both men and women. Perceived relationship dissatisfaction was the strongest predictor for emotional distress in both genders. This finding has already been demonstrated for women in the present sample [49
] and is consistent with previous research on couples [19
The results from one meta-analysis of the literature on the association between depression and marital satisfaction showed a weighted mean correlation across studies of -0.42 for women and -0.37 for men [23
]. This analysis reported on data from 26 studies involving about 3,700 women and 2,700 men. The correlations from this meta-analysis are about 0.1 higher compared to those in the present study (unadjusted b = -0.31 for women and -0.27 for men). This moderate discrepancy with previous results could partly reflect random fluctuations in rather small sample sizes, perhaps combined with a publication bias in which low or non-significant effects were not accepted for publication.
Some studies have demonstrated that the mental health of wives is more sensitive to relationship factors than the mental health of their husbands [69
], while others have shown that relationship quality seems to affect the level of psychological distress in similar ways for men and women [71
]. The present study showed that partner relationship satisfaction was the most important predictor of emotional distress in both men and women, and the effect sizes were similar across sexes.
Other risk factors
Somatic disease was among the stronger predictors for emotional distress in both genders. A strong relationship between physical and mental health problems has been demonstrated repeatedly. Individuals with somatic chronic disease frequently suffer from anxiety and depression [72
A minor subgroup of the sample (4.3% of the women, 3.4% of the men) was unemployed, and unemployment proved to be a very strong predictor of emotional distress, more so for men than women. Perhaps as expected during pregnancy, employment was less important for women than for men. A negative link between unemployment and psychological health is well documented [75
] and previous evidence has also shown stronger effects for men than for women [78
]. Our findings are also in line with the results of an earlier study that suggested that unemployment has a greater effect on men's health because of their role as "primary providers for the family," whereas women are protected by their nurturing roles [79
]. First-time motherhood was also among the clearest predictors for emotional distress in both genders. Some previous studies have shown that first-time motherhood is a risk factor for depression in pregnant women [32
]. Such an effect has not earlier, to our knowledge, been examined for fathers.
Overall--except for unemployment--the results leave an impression that risk factors for emotional distress are mainly the same for men and women.
Relationship dissatisfaction, low self-esteem, unemployment, high education, and somatic diseases in the male spouse yielded significant effects on women's emotional distress. Most women feel more vulnerable during pregnancy and may become more dependent upon their partner for emotional and practical support. Pregnancy may be a time when a woman needs more than ever to feel secure about her partner's feelings about her and their relationship and about his emotional and financial ability to take care of her and the new child. Three of the five spousal variables with significant effects on women also predicted emotional distress in men. All the cross-spousal main effects were relatively weak, however.
The results also show that experiencing a good partner relationship acts as a protective factor against some significant stressors. Relationship satisfaction had a quite strong buffering effect against low self-esteem and first time motherhood in both men and women and against unemployment and low family income in men.
Although the main cross-spousal effects were generally weak, some of the cross-spousal buffering effects were clearly stronger than trivial. For instance, the partner's relationship satisfaction showed adjusted standardized regression coefficients varying from 0.02 to 0.04, but buffered the effect of own (low) relationship satisfaction from -0.35 to -0.25 in women and from -0.38 to -0.20 in men. Thus, if the partner is satisfied with the relationship, this satisfaction may help both men and women cope better with some strains. In general, the buffering effects sizes did not differ much between women and men.
Strengths and limitations
High statistical power due to the large number of participants and precise estimates are among the most important strengths of this study. Small effects and even negative results are still highly informative because of the narrow confidence intervals. Some of the effect sizes are relatively small even if they are significant. This study reports on many risk factors, both in male and female spouses, in a critical period of life and the relationship. The large sample also makes it possible to detect interaction effects.
Nonetheless, our findings must be interpreted carefully because of some limitations. First, in cross-sectional studies, data are not informative regarding causal directions. The associations between relationship satisfaction and emotional distress are probably bidirectional. Therefore some of the estimates may be inflated by a reversed effect from poor mental health to relationship satisfaction and to other variables modelled as causal factors. This possible bias effect is less of a problem for the estimated buffering effects than for the main effects, however. For instance, if poor mental health affects social support, and thus inflates our estimates of the effects of social support on mental health, it probably does so essentially independently of relationship satisfaction. Accordingly, even if somewhat inflated, the effect estimates for social support in different strata of relationship satisfaction can still be compared.
Second, as in all studies based on questionnaires, there may be response biases that cause spurious correlations between self-reported predictor- and outcome variables. Third, the validity and reliability of the outcome measure and some of the predictor variables might be less than optimal. For instance social support is measured with a single item. Whereas the first and second limitation could have led to inflated estimates, the third could have deflated them. Fourth, the response rates were low. However this is not uncommon in large epidemiologic studies and does not necessarily imply an unrepresentative sample [80
]. Also, while preventing reliable estimation of the occurrence of mental health problems, a moderate sample selection is not expected to dramatically affect results from analytic epidemiology [80
]. Nevertheless, our results may have been somewhat biased due to sample selection. The most likely type of bias would be a moderate attenuation of the effect estimates due to restricted variance both for relationship satisfaction and for psychological distress.
Our sample consists of couples in a certain phase of life. Consequently, we do not know the extent to which the results can be generalized to other samples of couples. These pregnant couples may be in a vulnerable phase of life, in which the protective effect of a good relationship may be extra strong. Comparisons with future results from large scale normal population studies will show. Nonetheless, we still believe that these findings, showing the importance of a satisfying relationship, have implications for the population in general.