The current study explored a broad facet of stress generation, namely selection into potentially problematic life circumstances that may be stressful and contribute to depression and dysfunction. Specifically, the present study examined the factors that predict early childbirth (before age 20) and its consequences. The results supported the hypothesis based on prior research on stress generation, that young women with previous histories of depression by age 15 have higher rates of early childrearing compared with those with no early history of depression. In contrast to the generation of acute life events, the “creation” of a stressful context may affect multiple relationships and entail enduring challenges and demands that unfold over time and permeate daily life—in other words, create a potentially adverse life style. In keeping with the interpersonal perspective on depression, we found support for the hypothesis that girls' interpersonal dysfunction at age 15 is a mediator of the link between youth early depression and childbearing. Also as predicted, early childbearing is indeed a challenging experience that is associated with elevated rates of depressive symptoms and diagnoses of depression in females. Moreover, young depressed mothers have significantly more difficulties in parenting as reported by both themselves and their own mothers.
Finally, aspects of the intergenerational transmission of depression were illuminated. Results indicated that (grand)mothers' depression plays a role in the chain of events associated with early childbearing, and depression and parenting difficulties in young mothers. While (grand)mother depression did not predict higher rates of young childbearing in daughters, it predicted elevated depression scores associated with parenting beyond the effects of early onset depression. A key aspect of the intergenerational transmission of depression appears to be interpersonal impairments and early onset depression especially in daughters, which in turn is a risk factor for young childbearing and for being depressed and impaired in the maternal role.
In all of the analyses, gender differences were explored, and the predicted patterns were seen for young women but not young men. Males' having children was associated with lower family SES and conduct disorder, but not depression, whereas these predictors were reversed for young women. The finding that males' depression was not related to early parenthood, but conduct disorder was related, is similar to results from the National Comorbidity Survey (Kessler, et al., 1997
). However, caution is in order given the small sample of young men with children—and especially of those with conduct disorder—in the current sample. The small sample precluded further analyses of mediating processes, but findings suggest that further study of young parenthood in males, and its relevance to stress generation processes and to maternal psychopathology, is warranted.
Depression in young women by age 15 is a risk factor for early childbirth by age 20. This result is consistent with several prior studies that have found that youth depressive symptoms or diagnoses predicted early pregnancy or childbirth (e.g., Fergusson & Woodward, 2002
; Kessler et al., 1997
), although other research has shown associations with externalizing/conduct disorders rather than depression (e.g., Bardone et al., 1998
; Kovacs et al., 1994
), consistent with patterns for males observed in the present study. Limited numbers of girls with conduct disorder in the present study may have precluded detecting such patterns.
The results support the expansion of the construct of stress generation beyond the initial focus on associations between a previous history of depression and subsequent elevated rates of acute negative life events (Hammen, 1991
). The current study extends the predictions of stress generation models to suggest that selection into potentially chronically stressful life circumstances may also be a high-risk outcome of depression history, perhaps particularly of early-onset depression in young women. Elsewhere we have also shown that young women with histories of early-onset depression select themselves into maladaptive romantic relationships in which they have an increased likelihood of being victims of severe domestic violence (with legal and medical involvement)(Keenan-Miller et al., 2007
). Maladaptive partner selection with violent discord, and early childbearing, are two areas that may have long-term stressful, disruptive, and threatening consequences. The creation of a parenting relationship with a child is certainly challenging. Women who are teens at the birth of a first child may face a cascade of stressors that could include stressful home environments and difficulties in parenting skills, and as well as educational, financial and occupational disadvantage (e.g., Fergusson & Woodward, 1999
; Jaffee et al., 2001
). Thus, becoming a mother at a young age is commonly fraught with stressful challenges that may increase the likelihood of psychological maladjustment.
Although we use the term “selection” into stressful circumstances (e.g., Kendler, Karkowski, & Prescott, 1999
), it is not meant to imply conscious or deliberate action, and it is certainly not a single decision but a complex set of choices and actions that likely differ from person to person. Considerable research has shown varied predictors of different reproductive decisions and behaviors in teens (e.g., age and nature of sexual activity, contraception use, number of partners, pregnancy, sexually transmitted diseases), but we agree with the authors of recent reviews who note that understanding the mechanisms by which these predictors operate remains as a further stage of research (e.g., Gloppen et al., 2010
; House et al., 2010
; Markham et al., 2010
In the present study we also tested the hypothesis of a mediating role of interpersonal difficulties at age 15 as a link between early depression and early childbearing in females. The significant mediating effect is consistent with the hypothesis that difficulties in peer, family, and romantic relationships not only predict future depression outcomes, but also predict creation of social environments that are contentious and demanding. Such patterns are evident by at least age 15, but in fact may be developing from a young age and over a long period of time. It may be speculated that such patterns reflect dysfunctional attachments in the family and exposure to conflict in intimate relationships and maladaptive models of social problem-solving—and may also reflect temperament and personality predispositions. Further study is needed to explicate how interpersonal difficulties and depression may eventuate in pregnancy and the decision to give birth, and such research should consider social-cognitive processes, interpersonal skills and problem-solving, and the role of supportive resources (or lack of) among the many factors that come into play.
A further implication of the stress generation model is the vicious cycle of depression-stress-depression. The pattern is illustrated in the present study, revealing that those girls who were depressed by age 15 and who had babies at an early age were more likely to experience depression symptoms and recurrent diagnoses at age 20 than those who did not have children early. BDI scores showed an interaction effect such that childbearing was particularly strongly associated with current symptoms for those women with early onset depressive disorders, possibly indicating heightened sensitivity to stressors among those with early onset depression.
In addition to illustrating the vicious cycle of depression-stress-depression that portends chronic and recurrent depression, the results also highlight an important mechanism of the intergenerational transmission of depression. The current study captures the dysfunctional parenting of young depressed mothers, many of whom are offspring of depressed (grand)mothers. For those daughters of depressed (grand)mothers who have a child and who are depressed, their parenting may also contribute to the eventual transmission of depression and maladjustment in their own children. Daughters of depressed (grand)mothers were not more likely to bear children than daughters of nondepressed (grand)mothers, but they were significantly younger at the birth of a first child than daughters of nondepressed (grand)mothers. Also, daughters of depressed (grand)mothers who had a child were more likely to be depressed at age 20 than daughters of nondepressed (grand)mothers who had a child. In addition to contributing to earlier age of childbearing and greater depression associated with childrearing, having a depressed (grand)mother also contributed in two indirect ways. (Grand)maternal depression contributed to youth depressive diagnoses by age 15 and also to more maladaptive interpersonal functioning at age 15, both factors in predicting early childbirth. These findings are all consistent with a large body of evidence of mother to child transmission of risk for depression (e.g., reviewed in Goodman, 2007
; Hammen, 2008
), and with emerging studies of patterns of depression and disorder in three generations (e.g., Pettit, Olino, Roberts, Seeley, & Lewinsohn, 2008
; Weissman et al., 2005
). In much of the research on intergenerational transmission of depression, a key mechanism appears to be dysfunctional parenting (e.g., Goodman, 2007
). The current study does not report on psychological maladjustment in the offspring of young children of depressed daughters of depressed (grand)mothers. However, it does illustrate the risk for dysfunctional parenting especially among those young women who are currently depressed—a pattern that could portend maladjustment in the young children.
Gender differences consistently indicated more associations of depression with having children for females than males. As noted, the sample size of males who became parents was small, and a larger sample may yield different findings. However, there are reasons to speculate that the gender differences reflect several factors that put young women at greater risk: they typically have more control and more responsibility for decisions about childbearing after becoming pregnant and certainly may have more responsibility for day-to-day care of infants especially in nonmarital situations. Also, females are more susceptible to depressive reactions to stress; daughters of depressed women, more than sons, experience greater likelihood of early onset-recurrent depression (Hammen, Brennan, Keenan-Miller, & Herr, 2008
). Young women with interpersonal difficulties may be more likely to perceive the parenting role as a desirable and available option than young men would. However, males with depression histories may have different pathways to stress generation in selecting maladaptive environments, and further study of such choices is needed.
It must be clearly acknowledged that early childrearing is by no means a negative outcome for many women. Yet selection into early parenting may be problematic for some youth, with consequences including depression, parenting impairment, and adverse economic and social outcomes (Fergusson & Woodward, 1999
; Jaffee et al., 2001
; Meade et al., 2008
). Further study is warranted that attempts to clarify the conditions under which such families may thrive rather than experience dysfunction. Moreover, it is noted that the present results may not necessarily generalize to different cultural contexts. In Australia where the current study was conducted, the sample was predominately white, and there is less concern for the issue of teenage childbirth at the level of public policy, compared to the US and some other Western nations, according to a UNICEF report (UNICEF, 2001
; Shaw, Lawlor, & Najman, 2006
). Nevertheless, the current study indicates problematic potential outcomes for parents and their children stemming from early childrearing among youth with early onset of depression in young adolescence. It is possible that results might be different in U.S. samples where teen births are considered to be a significant public health concern, and are more heavily concentrated in nonwhite populations where poverty is high and access to supportive care and medical services is inadequate. SES factors were not significantly related to early birth in the female Australian youth population, which was relatively economically and racially homogeneous. Conceivably, greater social disadvantage and different ethnic and cultural experiences could play more of a role than depression in predicting early childbirth, and thus it is unclear whether the results of the present study would generalize to nonwhite or economically more disadvantaged groups.
Several further limitations of the current study are acknowledged. The childbearing sample included those with births by age 20, and findings based on younger samples might yield different patterns. Parenting data were limited to self- and (grand)mother-reports, rather than observations, and also no behavioral or developmental data on the babies themselves were available. The construct of interpersonal functioning at age 15 was based on a composite of indicators of functioning in various social roles, but more specific probes of the kinds of interpersonal behaviors that are predictive of selection into childbearing are needed. Similarly, the current study focused on the role of youth and (grand)maternal prior depression in the pathway to childbearing by 20 and its consequences, but obviously multiple factors that were not the focus of the present study are likely to also play a role, including educational attainment, (grand)mothers' own early childbearing, other forms of psychopathology, social supports, and quality of the relationship with the baby's father. Moreover, it is likely that various factors in the mothers' lives at age 20, in addition to having a child, affect the occurrence of depression. In future studies more complete models of prediction of depression in young mothers should include quality/presence of intimate and supportive relationships, living conditions, and income, among others.
Despite caveats about its generality to males and nonwhite samples, the study contributes to further understanding of one of the deleterious correlates of depression: the tendency to contribute to the creation of acute stressors and problematic life contexts that portend further depression and stress. There are several notable clinical implications. Diagnoses of depression by age 15 are a risk factor identifying young women who may need to be targeted for treatment and prevention of depression. Specifically, they also may be at risk for interpersonal difficulties that can lead them to select into challenging life situations that portend further depression. Early onset depression is commonly accompanied by difficult and stressful family and peer relationships that may overwhelm youths' coping capabilities, so that interventions are needed that treat not just the depression but also the underlying vulnerabilities and skill deficits. The study also underscores the risks to offspring of depressed mothers, and especially to daughters of depressed women who suffer from early onset depression and interpersonal difficulties. Depression may continue to run in families, unless deflected with interventions that identify youth at risk at early ages (e.g., Compas et al., 2009
; Garber et al., 2009
). The current study also highlights the potential impact of young women's depression on their parenting skills with the threat of maladjustment in the children who are exposed to significant nonoptimal parenting. Thus, early childbearing in girls at risk for depression might be a particularly high risk situation for both the welfare of the young mother and her child. Programs for low income mothers who have high levels of risk factors, such as assistance that provides integrated psychological care and supportive services, might serve as models for intervention (e.g., Ammerman, Putnam, Bosse, Teeters, & van Ginkel, 2010