Abstract
The literature indicates a robust negative relationship between depression and couple relationship satisfaction. However, less is known about the differential effects of romantic relationships on depression over time and whether one or both partners experience depression. Using data from 1215 couples across 4 years, we sought to examine couple classes of depressive symptom trajectories and investigate the degree to which relationship satisfaction predicted class membership. Using joint-probability growth mixture modeling, we found three couple classes of depressive symptom trajectories: women’s moderate, men’s low class, men’s moderate, women’s low class, and men’s and women’s low class. Logistic regression results revealed both men’s and women’s higher relationship satisfaction was associated with women’s moderate, men’s low class membership while both partners’ higher relationship satisfaction was not associated with men’s moderate, women’s low class membership, in comparison to the men’s and women’s low stable class. These findings contribute to the literature by identifying the heterogeneity of patterns of depressive symptom trajectories among couples and the association of relationship satisfaction with couple classes.
Depression is the leading contributor of disability worldwide (World Health Organization [WHO], 2017). Each year, approximately 3–7% of adults around the globe suffer from depression (Lim et al., 2018; WHO, 2017). The proportion of the population with depression varies by geographic region, with the highest rates in Africa and the Americas and the lowest rates in the Western Pacific. Depression, along with anxiety, carries significant costs to individuals, families, and society including a $1.15 trillion annual global economic burden (Chisholm et al., 2016). The risk of developing depression increases with exposure to adverse social and economic conditions, including relationship conflict and dissolution and poor health (WHO, 2017). Depression is heterogenous, which means that individuals experience different trajectories of depressive symptoms over time and thereby suffer at disproportionate rates (Eaton et al., 2008).
Heterogeneity in the Course of Depressive Symptoms
Long-term trajectories of depressive symptoms are heterogenous, meaning that some people experience depression as a single brief episode, others report recovering from multiple episodes, and some endure recurrent and persistent symptoms for years (Klein & Allmann, 2014). This means that people may experience depressive symptoms as transient, intermittent, or stable (Eaton et al., 2008). One prospective population-based study of participants over 23 years found that about 50% of those who experience a depressive episode recover and have no additional episodes, 35% experience recurrent depression, and 15% experience unremitting symptoms (Eaton et al., 2008). A systematic review of 25 studies on the heterogeneity of depressive symptom trajectories identified variation in terms of severity of symptoms (i.e., low, medium, and high) and stability of symptoms (i.e., stable, increasing, and decreasing; Musliner et al., 2016). Most prior group-based trajectory modeling studies have identified either three or four classes of trajectories of depressive symptoms that vary by severity and stability, with the majority of community-based samples including participants with low or no symptoms. Predictors of poor depressive symptom trajectories include variables such as female gender, low education, and low income. Findings also suggest that women’s symptoms endure longer compared to men (Eaton et al., 2008).
Romantic Couples and the Course of Depressive Symptoms
Romantic relationships are a vital context to examine because they can affect the course of depressive symptoms by improving, maintaining, or worsening symptoms (Whisman et al., 2021). These effects are supported by three main theories: Coyne’s interpersonal model of depression (Coyne, 1976), the marital discord model of depression (Beach et al., 1990), and the stress generation model (Hammen, 1991). Broadly, these theories describe interrelations among depressive symptoms and difficulties in close relationships (Rehman et al., 2008). Coyne’s interpersonal model notes that depressed individuals seek frequent reassurance from their partner, which can lead to cycles of interpersonal problems and depressive symptoms (Coyne, 1976). From a stress generation perspective, dependent stressors – life events influenced by the depressed individual such as getting into an argument – are more strongly associated with depressive symptoms than independent stressors that are outside of an individual’s control (Bos et al., 2007; Davila et al., 1997; Kendler et al., 1999). Finally, the marital discord model (Beach et al., 1990) also explains how relationship conflict can have lingering effects on relationships, which can worsen depressive symptoms in one or both partners over time. Although these theories have distinct differences, they all suggest a link between depressive symptoms and relationship problems. Individual differences among partners give way to differences in how couples experience depression and how depressive symptoms and interpersonal stress unfold for each partner over time.
Couple Classes of Depressive Symptom Trajectories
Researchers have historically identified different types of couples by partners’ depressive symptoms or diagnoses and sex. For example, heterosexual couples in which one partner (either male or female) has depression are often compared to heterosexual couples not experiencing depression (e.g., Byrne & Carr, 2000; Gabriel et al., 2016; Gotlib et al., 1989; Leung et al., 2017; Sacco et al., 1993). Generally, this literature supports the idea that depressed couples, regardless of which partner is depressed, experience more relationship problems and stress than non-depressed couples. However, most of these studies recruited couples with depressed women and few studies included couples with depressed men (e.g., Byrne & Carr, 2000; Sacco et al., 1993; Gabriel et al., 2010), which complicates the examination of sex differences among couples. Of the few studies that did examine couples with depressed men and couples with depressed women, depressed women were more vulnerable to greater relationship distress than men (Gabriel et al., 2016). On the other hand, both groups of couples were found to be similar in that both depressed men and depressed women were more critical and demanding of their nondepressed partners (Gabriel et al., 2010).
While the existing findings offer some insight, there are gaps in the literature that warrant further exploration. Prior studies used small samples ranging from 22 to 80 couples (Gotlib et al., 1989; Ruscher & Gotlib, 1988). Although these studies used samples from clinical populations, the small sample sizes limit generalizability. Furthermore, it is unclear whether these differences and similarities between couples with depression exist in large, broad, and representative population-based samples. This is important because presenting with subclinical depressive symptoms is common. Further, studying population-based samples improves the generalizability of findings. Hence, we aim to use a large representative sample of couples in Germany.
Prior studies also did not examine heterogeneity among couples’ depressive symptom trajectories. For example, the literature generally classified partners’ depression as binary (e.g., depressed or not depressed) through the use of cut-off scores from clinician rated or self-reported measures. This limits our understanding of depression because depression can vary by severity and stability over time and severity and stability can vary among partners (American Psychiatric Association, 2013). Heterogeneity is often examined in mixture models that identify various types of depression based on patterns and trends in the variation of the sample. Testing the heterogeneity of depression allows researchers to parse out groups of people who experience different levels of symptomatology over time. We identified one previous study that used mixture modeling on a large sample of German couples that identified four types of couples ranging in level of depressive symptoms and conflict at one point in time (Morgan et al., 2020). The study of a large population-based sample illustrated that partners and couples vary in severity of depressive symptoms.
The prior empirical literature mostly relied upon cross-sectional analyses of couples, so it is not possible to understand changes in the course of depressive symptoms over time among different types of couples. This is a crucial next step in the research since many partners’ depressive symptoms are recurrent and chronic (Klein & Allmann, 2014; Musliner et al., 2016). To capture both the heterogeneity of depressive symptoms and how depressive symptoms change over time, prior researchers have used growth mixture modeling to examine trajectories over time (Musliner et al., 2016). However, there is no known study that has identified various types of depressive symptom trajectories among couples. This is important because the literature remains focused on the average trajectory of depressive symptoms and provides limited understanding of the heterogeneous nature of depressive symptoms among couples. Given that the previous literature supports that couples in which one or both partners have depressive symptoms also experience greater relationship distress, it remains unclear how different types of couples with depressive symptoms differ over time. Understanding the course of depressive symptoms among different types of couples is important because it can provide clinicians and researchers insights about the course of depressive symptoms for different types of couples that often present in clinical settings. Hence, we aim to identify different types of couples with different depressive symptom trajectories.
Present Study
We aimed to explore different types of depressive symptom trajectories among couples and their association with relationship satisfaction. More specifically, this study investigated the following research questions: (1) What were the couple classes of men’s and women’s trajectories of depressive symptoms over 4 years, and (2) To what extent were men’s and women’s relationship satisfaction associated with the identified couple classes. Specifically, joint-probability growth mixture modeling (JPGMM; Li et al., 2002) is an extension of growth mixture modeling that can estimate classes of two partners’ trajectories of depressive symptoms simultaneously, instead of only one partner’s trajectory (e.g., Lavner & Bradbury, 2010). Thus, by using JPGMM, we identified dyadic classes of trajectories of depressive symptoms among couples, investigated differences in changes in depressive symptoms by partner and couple, and examined the association between relationship satisfaction and class membership. Finally, we accounted for individual personality factors (i.e., neuroticism), which are potential confounding factors among couples with depression (Cao et al., 2017; Whisman et al., 2006).
Method
In this study, we used five waves of data across 4 years from the longitudinal Pairfam study (release 9.0; Brüderl et al., 2018; Huinink et al., 2011). The Pairfam investigators used a stratified sampling design to collect a representative sample of adults in Germany. Focal participants were recruited by birth year cohorts (i.e., 1971–1973, 1981–1983, and 1991–1993). Focal participants completed in-home interviews annually starting in 2008, and the partners of focal participants were recruited to complete return-by-mail questionnaires. We used Waves 2, 3, 4, 5, and 6 (2009–2013) in this study because depressive symptoms were measured starting in Wave 2. Although there were 2687 couples at the beginning of Wave 2, there was a general attrition in couples over time (Wave 3, n = 2362; Wave 4, n = 2182; Wave 5, n = 2039), with 1992 couples remaining in the study at Wave 6. We included couples who remained together across the waves and excluded data from any new partners of the focal participants at later waves, which resulted in a sample of 1297 couples. Next, we excluded divorced and separated couples (n = 37), one widowed individual, and those with missing values on relationship status (n = 37) at Wave 2 only, which reduced the sample to 1251 couples. At each subsequent wave, there were very few (i.e., 5 or fewer) couples who divorced or separated and any data provided by these couples were retained. We also excluded adolescents (i.e., aged 17 and younger, n = 36) because of the well-documented differences in relationship dynamics among adolescents compared to adults (Lantagne & Furman, 2017), which resulted in a final sample of 1215 couples.
Participants
Descriptive Statistics (N = 1215 couples).
aReference group is German migrants.
bReference group is couples committed to each other, but living in separate residences. Unless specified, all of the variables were measured at Wave 2.
Measures
Depressive Symptoms
Ten items from the State-Trait Depression Scale (STDS; Spaderna et al., 2002) were used to assess depressive symptoms. Only the trait depression items were used, which were intended to assess how participants felt in general as opposed to how they felt at the time of assessment. The STDS specifically assessed cognitive-affective symptoms of depression. The STDS was designed for use with non-clinical samples (Krohne et al., 2002) similar to the current sample. The STDS was highly correlated with common measures of depressive symptoms often used with clinical samples (Spaderna et al., 2002), such as the Beck Depression Inventory (Beck & Steer, 1987) and Zung Self-Rating Depression Scale (Zung et al., 1986). Scale items ranged from euthymia (e.g., “I am happy” and “I feel good”) to dysthymia (e.g., “I am depressed” and “My mood is melancholy”), which were rated from 1 (almost never) to 4 (almost always). The euthymia items were reverse coded so that higher values indicated absence of positive affect, thereby reflecting higher levels of depressive symptoms. The scale had acceptable internal consistency for Wave 2 (men α = .85, women α = .89), Wave 3 (men α = .86, women α = .89), Wave 4 (men α = .86, women α = .86), Wave 5 (men α = .91, women α = .89), and Wave 6 (men α = .89, women α = .87).
Relationship Satisfaction
One item from the German Relationship Assessment Scale (RAS; Sander & Böcker, 1993) measured global satisfaction of the romantic relationship at Wave 2. Specifically, partners rated, “All in all, how satisfied are you with your relationship” with a score ranging from 0 (very dissatisfied) to 10 (very satisfied). This single item has been compared to the full RAS and was found to be a valid and reliable measure of overall relationship satisfaction among couples (Fülöp et al., 2020).
Controls
We used several control variables that were all measured at Wave 2, including age (years), number of children, ethnicity (0 = Non-German native, 1= German native), household income (euros), health (rated 1 [bad] to 5 [very good]) and relationship status (cohabitating [0 = other relationship statuses, 1 = cohabitating], married [0 = other relationship statuses, 1 = married]). Education was measured by the international standard classification of education that ranged from 0 (not currently enrolled in education) to 9 (equivalent to university level education) where higher numbers indicated greater education (UNESCO, 2006). Finally, four items from the Big Five Inventory (Rammstedt & John, 2005) assessed partner’s neuroticism (men α = .67, women α = .72), on a rating scale from 1 (absolutely incorrect) to 5 (absolutely correct).
Missing Data
We examined the skewness and kurtosis of the data and the amount of missing data. Household income as well as men’s and women’s relationship satisfaction had high kurtosis values (i.e., greater than 5; Kline, 2016). Consequently, we recoded the values outside 3 standard deviations to be 3 standard deviations from the mean, which resulted in acceptable kurtosis levels. Missing data were low and ranged from 0% (e.g., men’s and women’s ages) to 9% (e.g., men’s relationship satisfaction). Little’s test revealed that missing was not missing completely at random (χ2 (2489) = 3141.56, p < .01). We further evaluated missing data associations by coding all the outcomes, predictors, and controls as missing variables (e.g., missing = 1, observed = 0). We then tested bivariate correlations of the missing data variables (5 controls had no missing and were excluded from bivariate correlations). Forty-five percent of the 200 bivariate correlations were correlated at p < .05, ranging from r = −.06 (women’s relationship missing was negatively associated with men’s depressive symptoms missing at Wave 4) to r = .97 (women’s health missing was positively associated with women’s neuroticism missing at Wave 2). Full-information maximum likelihood estimation was used to handle missing data by estimating parameters from all of the available data in the variance and covariance matrices (Acock, 2005).
Data Analysis
Using Mplus 8.0 (Muthén & Muthén, 1998–2017), we began with a series of unconditional latent growth models. Specifically, we examined unconditional latent growth models of men’s and women’s trajectories of depressive symptoms separately. Latent constructs of women’s initial (i.e., intercept) and rates of change (i.e., slope) of depressive symptoms were composed of women’s depressive symptom scores at Waves 2 through 6. Wave 2 was coded 0 with Wave 6 coded as 1 while Waves 3–5 were freely estimated to account for nonlinear trends in the trajectory. Next, we assessed a conjoint model composed of both partner’s trajectories of depressive symptoms simultaneously with men’s and women’s initial and rates of change covarying. Each model was evaluated by a common fit index (CFI) greater than .95, and root mean square error of approximation (RMSEA) and standardized root mean square residual (SRMR) less than .05 (Kline, 2016).
We then added a categorical latent construct for the couple classes of men’s and women’s initial and rates of change for trajectories of depressive symptoms. Relationship satisfaction for men and women were then added as predictors of the couple class latent construct; control variables were also added (see Figure 1). With Waves 3–5 being freely estimated, we examined change in the slopes over time by calculating percent changes in trajectories at specific waves in addition to the overall rates of change estimate (i.e., slope). Similar to growth mixture modeling procedures (Soloski & Durtschi, 2020), we then used an iterative approach to test the model from one to five classes, to assess the best fitting number of classes. Specifically, we evaluated if models improved when latent variances and covariances between and within dyadic classes were constrained or freely estimated, which were similar to homogeneity of variance tests in ANOVA (Soloski & Durtschi, 2020). The number of classes were evaluated by the following indices: model convergence and warnings, Loglikelihood, Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), Sample-size Adjusted BIC (ABIC), Lo-Mendell-Rubin Adjusted Likelihood Ratio Test (LMR-RT), and entropy. Fit indices, theory, and parsimony all informed the class selection. Finally, logistic regression was used to examine the degree to which relationship satisfaction and the controls predicted class membership. Joint-probability growth mixture model.
Results
Unconditional Models
We ran unconditional models for both men’s and women’s trajectories of depressive symptoms separately, which each had good model fit (men: CFI = .99, RMSEA = .04, SRMR = .04; women: CFI = .99, RMSEA = .05, SRMR = .04). Next, we examined men’s and women’s trajectories of depressive symptoms conjointly, which also had good model fit (CFI = .99, RMSEA = .03, and SRMR = .03). Both partners reported low levels of depressive symptoms (men: M = 1.58, SE = .01, p < .01; women: M = 1.67, SE = .01, p < .01) that had small increases over time (men: M = .08, SE = .01, p < .01; women: M = .05, SE = .01, p < .01) with variances at p < .01 for both partners’ initial levels (men: σ 2 = .12, SE = .01; women: σ 2 = .17, SE = .01) and rates of change (men: σ 2 = .06, SE = .01; women: σ 2 = .04, SE = .01). This conjoint unconditional model established a single class of couples with average trajectories of depressive symptoms for both men and women.
Determining Classes
Descriptive Statistics of Indicators for Number of Class in the Conditional Models (N = 1215 couples).
Note. Con = Converge, LL = Loglikelihood, AIC = Akaike Information Criterion, BIC = Bayesian Information Criterion, ABIC = Sample-size adjusted BIC, LMR-RT = Lo-Mendell-Rubin Adjusted Likelihood Ratio Test, Ent = Entropy, C%= Percentage of sample in class indicated. The bolded row is the model that was selected as optimal. *p < .05.
Three-Class Model
The three-class model reveled three dyadic classes of both partners’ trajectories of depressive symptoms (see Figure 2). The majority of couples in our sample were in the men’s and women’s low stable class (56%). Participants in this class reported low initial levels of depressive symptoms (b = 1.38, p = .01 for men; b = 1.46, p = .01 for women) that increased an average of 6.84% for women (b = .10, p < .01) and 6.54% for men (b = .09, p < .01) across the five waves. Three couple classes of dyadic trajectories of Men’s and Women’s depressive symptoms across four years. Note. Wm, ML = Women’s Moderate, Men’s Low class; MM, WL = Men’s Moderate, Women’s Low class; MWL = Men’s and Women’s Low class.
About 21% of couples were in the women’s moderate, men’s low class. This class included women who reported moderate levels of depressive symptoms (b = 2.16, p < .01) that remained stable over time (b = .01, p = .59). Women reported their depressive symptoms worsened late in the study period, with a 1% increase in symptoms at Wave 5. The men in this class reported low levels of depressive symptoms (b = 1.62, p < .01) that increased an average of 5.80% over time (b = .09, p < .01).
The remaining couples (23%) were in the men’s moderate, women’s low class. This class was comprised of men with moderate initial levels of depressive symptoms (b = 1.99, p < .01) that remained stable over time (b = .00, p = .96). Men reported their depressive symptoms worsened late in the study period, with a .01% increase in symptoms at Wave 5. Women reported low initial levels of depressive symptoms (b = 1.60, p < .01) that remained stable and did not vary over time (b = .08, p = .11). The variances, which were constrained to be the same across the classes, were small for the intercepts (women: σ2 = .08, p < .01; men: σ2 = .06, p < .01) and rates of change (women: σ2 = .03, p < .01; men: σ2 = .04, p < .01).
Class Membership
Unstandardized Parameter Estimates, Odds Ratios, and Significance Levels for Dyadic Growth Mixture Models (N = 1215 couples).
Note. Reference class is men’s and women’s low class (66%). All predictors were measured at Wave 2. *p < .05.
Discussion
This study extends our previous work in which we investigated dyadic classes of both partners’ depressive symptoms at one time point (Morgan et al., 2020). This is the first known study to examine dyadic classes of both partners’ depressive symptoms over time. Previous studies have tested depression classes for either one person (e.g., Musliner et al., 2016) or both partners in separate models (e.g., Lavner & Bradbury, 2010), which offers a limited understanding of dyadic processes. We sought to examine couple classes of depressive symptom trajectories and investigate the degree to which relationship satisfaction predicted class membership. In response to our first aim, we identified three classes of couples’ trajectories of depressive symptoms: women’s moderate and men’s low class, men’s moderate and women’s low class, and men’s and women’s low stable class. The identification of these couple classes indicated that couples vary in regard to whether one or both partners experienced depressive symptoms and the severity of symptoms experienced over time. Findings related to the second aim highlighted nuance in the way relationship satisfaction associated with these classes. Findings relevant to each class will be discussed further below.
Men’s and Women’s Low Stable Class
The majority of the sample in this study was in the men’s and women’s low stable depressive symptom class (66%). This was to be expected since studies of community samples typically report lower rates of depressive symptoms (e.g., Fredriksen et al., 2019; Kouros & Cummings, 2011) compared to clinical samples. Unlike the other classes, both partners in this class reported similar trajectories of depressive symptoms, suggesting that they had similar experiences regarding the severity of depressive symptoms over time. Although women reported slightly higher depressive symptoms than men in this class, they both had low initial levels of symptoms that slightly increased over time.
Given the low levels of depressive symptoms, it is unsurprising that couples in this class were more likely to be satisfied with their relationship when compared to the women’s moderate, men’s low class. This is consistent with the extant literature, which demonstrated that non-depressed couples report higher relationship satisfaction and less relationship stress (e.g., Byrne & Carr, 2000; Gabriel et al., 2016). These couples were also more likely to be in better health than the other two classes, which is consistent with literature that those in better health are less likely to be depressed (Musliner et al., 2016).
Women’s Moderate, Men’s Low Class
Unlike the men’s and women’s low stable class, the other two classes included couples composed of partners who differed in their severity of depressive symptoms. Particularly, women experienced higher severity of depressive symptoms compared to their partners in the women’s moderate, men’s low depressive symptom class. More specifically, women in this class experienced moderate levels of depressive symptoms that varied over time, slightly increasing initially and then decreasing in later years. Their partners on the other hand, had low initial levels that increased over time. That women’s symptomatology improves and worsens over time suggests that there could be both competing efforts to decrease and increase their symptoms. Furthermore, given that men’s depressive symptoms increased over time suggests that they may be negatively affected by women’s symptoms as time progresses. This finding aligns with the stress generation theory (Hammen, 1991) and Coyne’s interpersonal theory (Coyne, 1976; Lemay & Cannon, 2012), which suggest that one partner’s symptomatology can negatively affect the nondepressed partner and increase their odds of developing depression.
Contrary to these theoretical assumptions, both women and men in this class had lower odds of higher relationship satisfaction at Wave 2. This poses an interesting dynamic for these couples in that only women experience greater depressive symptoms, but both partners had lower odds of higher relationship satisfaction. This sex difference in depressive symptoms has been widely debated and has many possible explanations (Hilt & Nolen-Hoeskema, 2014). From a stress generation lens, one possible explanation could be that women experience greater relationship distress and when depressed are more susceptible to distress in their relationship, which corroborates with one previous study (Gabriel et al., 2016). Furthermore, partners with depression can experience a depressogenic bias where they perceive greater negativity about their relationship than their partners (Cowden et al., 2011). For men, it is possible that they feel less satisfied in their relationship because their partner’s depressive symptoms strain their interactions with their partner (Sharabi et al., 2016).
In addition to relationship satisfaction, neuroticism was a significant predictor in of couple classes. In fact, women’s higher neuroticism had a larger association with membership in this class than relationship satisfaction. This is consistent with prior research in which wives’ neuroticism was associated with depression (Cao et al., 2017). Membership in this class also appeared to be related to health stressors since men and women in better health were less likely to be in this class. German native-born individuals were also less likely to be in this class, which suggests that there are more immigrant couples in this class; this aligns with prior research indicating that immigrant couples in Germany are likely to experience depression (Tibubos et al., 2018). From a stress generation perspective, it is possible that for immigrant women, living in a foreign country brings more stress such as economic and family stress, that leads to depression. Many immigrant couples in our sample reported living in Germany for more than a decade and it is possible that some stressors may have been present for years and could have affected women’s depression for years. Additionally, one study showed that immigrants in Germany from Turkey and Southern Europe had small, but greater declines in their mental health trajectories over time (Nesterko et al., 2019). Due to small sample sizes of couples from Turkey and other countries in this sample, we were unable to further examine differences in our study among participants from different countries. In light of our findings, however, we encourage future research to continue to study the course of depression among immigrant couples.
Men’s Moderate, Women’s Low Class
Finally, in the men’s moderate, women’s low class, men experienced moderate levels of depressive symptoms that remained stable over time while their partners experienced low levels of depressive symptoms that increased over time. There were fewer couples in this class, which is also consistent with the literature that suggests more women report depression than men (for an overview see Hilt & Nolen-Hoeskema, 2014; Salk et al., 2017). Despite these sex differences, this class illustrates that among some couples, men experience moderate levels of depression that persist over time, while women experience low levels of symptoms. In contrast to the women’s moderate, men’s low class, men’s and women’s relationship satisfaction was not associated with being in this class. Furthermore, the association of men’s and women’s relationship satisfaction did not differ between this class and men’s and women’s low stable class. This is surprising because we would expect partners in this class to experience less relationship satisfaction. This finding is in contrast to the marital discord model of depression (Beach, et al., 1990) and recent research on European couples showing that men’s and women’s greater marital discord is associated with higher depressive symptoms in themselves and in their partners (Salinger et al., 2020). This finding may be attributed to men’s neuroticism, which was the only predictor of this class. This finding adds to the continuing discussion on confounding variables in the association between relationship satisfaction and depressive symptoms (e.g., Cao et al., 2017; Whisman et al., 2006). Previously, neuroticism was either not associated with depression or was associated with depression, but only for women (Cao et al., 2017; Whisman et al., 2006). However, these studies used samples with mild averages of depression. Our findings add to this work by suggesting that couples in which men experience moderate depressive symptoms and women experience no symptoms, men are likely to also experience higher neuroticism. Overall, neuroticism appears to be a notable factor in couples in which one partner experiences moderate depressive symptoms.
Limitations
This study extended prior research by examining longitudinal data using novel methods; however, there are a number of limitations that are important to acknowledge. Our sample was composed of a community population of German adults and may not reflect the experiences of clinical populations. Future research should explore these associations within clinical populations using more clinically relevant assessments of depression. Participants’ depressive symptom trajectories were all relatively stable, with slight variation over time for some partners, which limited our understanding of change over time. Our ability to understand the experiences of partners who were less satisfied with their relationship was limited because we excluded participants who were divorced at Wave 2, partners in this sample reported being generally satisfied with their relationship, and few couples divorced in later waves of the study. Further, this study used existing data that assessed biological sex, but not gender identity. Future research is needed to explore the course of depression among divorced and separated couples, as well as partners with non-binary gender identities.
Future research can also expand upon these findings by examining the documented bidirectional association between relationship satisfaction and depression (Morgan et al., 2018; Najman et al., 2014; Whisman & Uebelacker, 2009). This was beyond the scope of the study, which focused on identifying couple classes of depressive symptom trajectories. Further, prior literature noted self-esteem and stressful life events as possible confounding factors in examinations of couples with depressive symptoms (Cao, et al., 2017), and these variables were not assessed in the waves of Pairfam data used in this analysis. We encourage future research to further explore these possible confounding factors among couples with depressive symptoms.
Conclusion
This is the first known study to investigate couple classes of both partners’ depressive symptom trajectories. We identified three classes of couples’ depressive symptom trajectories: women’s moderate and men’s low class, men’s moderate and women’s low class, and men’s and women’s low stable class. Findings indicate that the course of symptoms varies by each partner’s severity, but generally remains stable over 4 years, except for couples with moderately depressed men in which their depressive symptoms worsened over time. Furthermore, moderately depressed partners are less satisfied with their relationships, which aligns with the three theories on depression among couples and prior empirical research. These findings suggest that partners with low symptoms, even among couples with men who report moderate symptoms, were just as satisfied with their relationship as partners in the low stable class. In conclusion, the course of depressive symptoms varies by partner and severity and couples with low depressive symptoms experience higher relationship satisfaction.
Footnotes
Author’s note
This paper uses data from the German Family Panel (pairfam), coordinated by Josef Brüderl, Sonja Drobnič, Karsten Hank, Franz Neyer, and Sabine Walper. Pairfam is funded as long-term project by the German Research Foundation. The current study was not funded.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
