The results of this study indicate that patterns of maternal depressive symptoms studied longitudinally from infant age one month until children made the transition to adolescence (age 12) were associated with adolescents’ self-reports of social and emotional adjustment at age 15. Over and above early sociodemographic risk, more chronic and prolonged maternal symptoms that were evident from infancy to early adolescence, predicted adolescents’ self-reports of general internalizing and externalizing problems, as well as more specific indicators of dysphoria, loneliness, and risk-taking behavior. Importantly, although chronic and severe maternal symptoms were associated with more self-reported problems in adolescent offspring as expected, this was also true for the group of teens whose mothers reported either moderately elevated symptoms or chronic symptoms that were at a subclinical level and elevated only in comparison to mothers who never reported elevated symptoms. Thus, our findings indicate that chronic symptoms in mothers at varying levels of severity predict poorer offspring adjustment in contrast to adolescents whose mothers never reported elevated depressive symptoms. However, somewhat inconsistent with this picture, the group of teens whose mothers reported early and decreasing symptoms did not differ on any outcome measure from teens whose mothers reported no significant symptoms. This is difficult to explain because mothers in the early and decreasing latent class reported symptoms that were never below those reported by mothers showing chronic subclinical symptoms.
Although other studies have linked maternal depressive symptoms to adolescent adjustment difficulties (Foster et al., 2008
; Frye & Garber, 2005
; Hammen & Brennan, 2003
), this is the first study of which we are aware to study the course of maternal symptoms prospectively at regular intervals from infancy to adolescence and then to utilize adolescents’ own reports of their adjustment to assess outcomes. The results point to the importance of ongoing maternal symptoms that may be a marker of genetic risk and also co-occur with family stress and less engaged and supportive parenting (Foster et al., 2008
; Goodman & Gotlib, 1999
; Sheeber et al., 2007
). Hammen and Brennan (2003)
likewise examined adolescent outcomes in their epidemiological sample followed prospectively, using retrospective reports to assess the timing of maternal depression. They found that either chronic, but mild symptoms or more severe, but short-lived symptoms were associated with offspring diagnoses of depression. The current study is consistent with their findings in implicating chronic maternal symptoms, even at subclinical levels, as a predictor of poorer adjustment in adolescence. Our results also indicate that a range of internalizing and externalizing problems are differentially predicted by the pattern and severity of maternal depressive symptoms. Furthermore, when interactions between patterns of maternal depressive symptoms and adolescent adjustment were found, they indicated that girls whose mothers reported ongoing symptoms of depression acknowledged more adjustment difficulties in adolescence than did boys.
It is important to keep in mind, however, that despite the pattern of significant differences in adolescent adjustment outcomes across maternal depression latent classes, scores on adolescent self-report measures were consistently below clinical cut-offs on the CDI and YSR Internalizing and Externalizing scales. The descriptive data presented in suggest that there is more variability in self-reported risky behavior and loneliness than the CDI and YSR, but these measures do not include clinical cut-offs. These findings make it clear that we are talking about variations in offspring adjustment that are generally within the normal range rather than identifying clinically significant problems. In addition, we recognize that our effects sizes are relatively small. Several features of the analytic model, however, must be considered when evaluating these small effects. First, we controlled for a number of covariates reflecting sociodemographic risk which themselves are likely to be correlated with adolescent outcomes; second, the outcomes themselves were moderately inter-correlated; and, third, in latent class models the standard errors for all parameters are typically inflated as a consequence of uncertainty in class membership, which in turn lead to smaller test statistics. Despite these caveats, the findings suggest that variability in adolescent adjustment is related to variations over time in maternal depressive symptoms, over and above sociodemographic indicators.
Overall, regardless of gender, adolescents whose mothers reported chronic symptoms of depression across childhood at differing levels of severity reported not only more internalizing symptoms, but also more dysphoria and/or loneliness. Contrary to expectation, both boys and girls whose mothers were in the moderately elevated and stable subclinical latent classes reported feeling lonelier, possibly suggesting more difficulties in the peer group as well as less support from family. Similarly, both boys and girls in the chronic latent class reported higher levels of dysphoric mood than adolescents whose mothers were never depressed and boys and girls with mothers in the elevated and stable subclinical classes both reported elevated levels of internalizing symptoms relative to those whose mothers were never depressed. Thus, we obtained fewer gender differences in adolescent self-reports at age 15 than we anticipated, suggesting that chronic symptoms in mothers in tandem with the relatively higher levels of sociodemographic risk that accompanied ongoing maternal symptoms predicted more anxiety, depression, somatic complaints and loneliness at age 15 regardless of gender. The two sex by latent class interactions were consistent with predictions in that girls whose mothers were in the chronic class reported more internalizing symptoms relative to boys and girls whose mothers were in the stable subclinical class reported higher levels of dysphoria than their male counterparts. Although this may suggest that some girls were more sensitive to the effects of maternal depression, the overall pattern of findings across measures, latent classes, and gender is only weakly supportive of this possibility.
It is also noteworthy that adolescents whose mothers reported chronic, elevated, and stable subclinical symptoms likewise reported engaging in more externalizing and risky behavior than did adolescents whose mothers never reported depressive symptoms. The one significant interaction effect suggested that girls whose mothers reported subclinical symptoms were higher on this measure than boys in this group. Although we expected to find elevations on externalizing and risky behavior as a function of maternal depression latent class, we anticipated that boys would be higher on these adjustment indicators than girls and that we would be likely to find an interaction between maternal depression latent class and child gender with boys higher than girls when their mothers were more chronically depressed. Although results supported the hypothesis of elevated externalizing problems, the gender interactions were inconsistent with expectation. Overall, our results suggest that when maternal symptoms are prolonged, both boys and girls report some adjustment difficulties in adolescence.
We modeled latent classes of maternal depressive symptoms in tandem with sociodemographic measures, thereby providing a description of demographic risk factors that co-occurred with longitudinal symptom patterns. Consistent with prior studies linking sociodemographic risk to depressive symptoms (e.g., Brown & Harris, 1978
; Cicchetti et al., 1998
; Dawson et al., 2003
; Hammen, 1991
), women who reported elevated symptoms were less likely to be married, had less education, and reported being in poorer physical health than women who never endorsed symptoms of depression. Depressed women may report feeling physically unwell, either because of reporter bias or because their depression is partly manifest in physical symptoms including aches and pains. Conversely, chronic health problems may contribute to feelings of despondency and sadness. Our data do not permit us to tease apart the direction of effects between physical health and sad mood, but this issue is important to consider in future studies examining the course of depressive symptoms in women. However, from the perspective of a child growing up with a chronically distressed mother, the cause of the distress may be less important than the fact that symptoms of depression are evident over time.
Women with elevated symptoms of depression in our sample, especially those with either moderately elevated
or chronic severe
symptoms, not only reported more health problems, but they were also less likely to be married at the time the study child was born. Whereas over 90% of the women with very low symptoms were married at the time of the study child’s birth, only about half the women in the two most stable and elevated symptom groups were married. Thus, they were more likely than never-depressed mothers to lack the benefits of spouse support, both emotionally and in terms of child care (Hopkins & Campbell, 2008
); lack of adequate social support and help with childrearing have been associated with postpartum adjustment in other studies (Campbell et al., 1992
). The lack of a relationship with a partner at the time of the study child’s birth may reflect the severity of dysfunction, in that depressive symptoms may have impaired these women’s ability to remain in a stable relationship with the infant’s biological father. In the current community sample, sociodemographic risk was quite stable (NICHD ECCRN, 2004
). Furthermore, when we examined the marital status of these women at adolescent age 15 in relation to adolescent adjustment (data not shown), differences in adolescent outcomes remained the same. This suggests that being single at the time of the study child’s birth is in itself a robust marker of sociodemographic risk. However, it remains unclear whether the risk reflects primarily the severity of the depressive symptoms and/or lack of financial and social support.
Number of children (Brown & Harris, 1978
) and planning for the pregnancy (Campbell et al., 1992
) also may be linked to patterns of depressive symptoms in childbearing women. In our data, women who reported elevated depressive symptoms that decreased by the end of the study child’s second year to a subclinical level (early-decreasing
) also had the most children. Although this difference was not significant once other covariates were controlled, their symptom levels may reflect the stresses of coping with several young children, and their symptoms may have abated somewhat as their older children entered school and became more self-sufficient.
In contrast, women who reported symptoms that were consistently stable
, but subclinical
were more likely than women who endorsed very low symptoms (never-depressed
) to have fewer children, but to describe their pregnancy as unplanned. They were also older, but only 68% were married at the time of the study child’s birth. Other research has noted a link between an unplanned pregnancy and clinically diagnosed postpartum depression in low risk married women having their first child (Campbell et al., 1992
). In the current study this link was more subtle because the women reported only subclinical, albeit stable, levels of depressive symptoms. This may suggest that women with chronic dysphoria are less likely to plan ahead and take precautions to avoid becoming pregnant than better functioning women, so the unplanned pregnancy may be a result of the chronic sad mood or it may be a sign of relationship difficulties. However, these women with stable subclinical
symptoms were also more likely to report that their pregnancy was unplanned than were women in the chronic, severe
depression latent class, complicating the interpretation of this intriguing finding.
Taken together, however, our data suggest that there are distinct patterns of maternal depressive symptoms over this 12-year period that are also related to sociodemographic risk and maternal physical health, with some women showing either subclinical or potentially clinically significant symptoms over the first twelve years of the study child’s life. Approximately 80% of the women in the sample never acknowledged symptoms above the accepted clinical cut-off score on our assessment measure, the CES-D, whereas the remaining 20% reported elevated symptoms at least some of the time, with some mothers showing a decline in symptoms by 24 months, and others showing either increases or high and stable symptoms. However, 31% of women reported symptom levels that while below the clinical cut-off of 16 on the CES-D, were still substantially elevated relative to the women in the never depressed group. Overall, then, a substantial number of children were being raised in a family where the mother reported either potentially clinically elevated levels of depressive symptoms or subclinical levels of symptoms that were still persistent. Their children’s adjustment at age 15 appeared to reflect something about being raised with a mother showing consistently elevated symptoms, as across the chronic, moderately elevated, and stable subclinical latent classes, adolescents reported both more internalizing (including loneliness and dysphoria) and externalizing symptoms (including more risk-taking) than did offspring of women who never reported elevated symptoms.
It should be noted that in this paper we identified five latent classes of maternal depressive symptoms, whereas Campbell et al. (2007)
identified six trajectories of symptoms using a different analytic technique. Several factors may account the slight discrepancies in patterns of maternal symptoms in these two analyses which both used the NICHD data set. The 2007 paper followed women from birth until their children were in first grade, that is for seven years, whereas in the current paper women were followed over a 12 year period. Thus, it is possible that fewer classes of symptoms emerged over this longer period of time. For example, the intermittent and moderate increasing trajectory groups identified by Campbell et al. (2007)
may have merged into the moderately elevated group identified in the current analysis. Furthermore, the current analysis included sociodemographic indicators in modeling latent classes, in contrast to the earlier paper which utilized only CES-D scores to identify trajectories. In addition, in the Campbell et al. (2007)
paper, only mothers with at least two CES-D scores were included (n
= 1261), whereas the current analyses included all study mothers with a CES-D score at 1 month (n
= 1363). The current analyses were, therefore, conducted on a somewhat larger sample. Despite these differences in analytic approach, the results are relatively similar in that both sets of analyses identified about 80% of mothers as showing very low to subclinical levels of symptoms over time, a small group showing chronic symptoms, and another 15-16% showing elevated, albeit variable patterns of symptoms over time.
The strengths of this study include the large sample followed prospectively from the study child’s birth, the frequent assessment of maternal depressive symptoms over a 12-year period, and the use of independent self-report measures to assess offspring adjustment in adolescence, 15 years after initial study recruitment. Moreover, the large community sample, selected for a study of child care rather than depression, means that this sample is relatively unbiased in terms of the issues under investigation in this report. However, this study also has several limitations including the reliance on questionnaire measures rather than diagnostic interviews to assess both maternal depressive symptoms and children’s outcomes. The inclusion of diagnostic interviews was beyond the scope of this study which focused on normal development in the context of family and child care experiences. Thus, our discussion focuses only on symptom levels and not diagnosable disorder. In addition, adolescent adjustment, even when poor relative to the offspring of mothers in the never-depressed
latent class, was well below a clinical level of distress. In addition, we did not assess stressful life events in the family that may partly account for the course of maternal depressive symptoms and for offspring functioning. We also did not include a measure of stress in the adolescent’s life that may have contributed to adolescent difficulties. Moreover, it is well-documented that stress and depression go together in complex ways because people who are more dysphoric and irritable may generate as well as respond to stressful life events (Hammen et al., 2004
; Rudolph & Flynn, 2007
). Thus, this descriptive, longitudinal study does not elucidate mechanisms that may account for either the chronicity of maternal depression symptoms or the links between maternal symptoms and adolescent adjustment. In addition, we do not have data on whether mothers received treatment for their depression. Unfortunately, we also could not address the influence of race and ethnicity on either latent classes of maternal depressive symptoms or on adolescent outcomes. There may be cultural influences over and above basic sociodemographic indicators that influence both maternal mood and adolescent adjustment that were not captured in our measures.
A further limitation of this study is our inability to assess the degree to which the familiality of dysphoria and other adjustment difficulties that is evident in our data reflects genetic risk, environmental risk, or their interaction. Relatedly, we are unable to assess the degree to which child effects were operating. However, evidence from one twin study indicates that even with controls for genetic variation, parenting and other environmental risks that co-occur with mother’s depressive symptoms, maternal depression predicts adjustment difficulties in children (Kim-Cohen, Moffitt, Taylor, Pawlby, & Caspi, 2005
). Future research with this data set that includes molecular genetic studies of adolescents and mothers may permit us to pursue this issue. Finally, analyses that examine more proximal family processes will be necessary to delineate the degree to which the quality of the mother-child relationship, the father-child relationship, and family social support, as well as events in the adolescent’s wider social network converge to either exacerbate problems or protect adolescents with chronically dysphoric mothers from developing more severe problems.