We showed that single depressed mothers, as compared to those from two-parent households, have poorer treatment outcomes. Specifically, single mothers were twice as likely to drop out of treatment, and were more than three times less likely to remit within the first 3 months even if they remained in treatment, suggesting that they are resistant not only to the treatment but also somehow to being in
treatment. Importantly, although the single mothers had significantly lower income and education levels (consistent with the body of literature showing an association between poverty and depression [8
]), their lower rates of remission held after adjusting for multiple socio-economic confounders. Thus, single mothers did not fare worse simply because they were poorer. In fact, subsequent examination revealed that single mothers had significantly impaired social-leisure functioning and that this impairment partially explained why they were less likely to remit. A number of possible mechanisms might account for this. For example, the presence of a male companion might have provided social support that enabled the mothers to function better and to respond better when undergoing treatment for depression. Conversely, low social functioning could have played a role in single depressed women not having a partner, and consequently not having the social support needed to buffer stressors that may have precipitated depressive episodes, and to stay in treatment. Or instead of either unidirectional pathway, some under-lying vulnerability trait(s) in the mothers could have commonly predisposed them to all of the observed outcomes. One such example that resonates with our observations is the mother’s interpersonal attachment style. Attachment theory posits that types of interpersonal attachment, which range from secure to insecure, form early in childhood experiences, are internalized, and become relatively stable by early adulthood across different interactions [2
]. Secure attachment styles are associated with comfortable dependence on others in relationships. Insecure styles, in contrast, are characterized by diminished self-esteem, discomfort with trusting or relying on others (relevantly, especially during times of distress or illness), and fear of intimacy [2
]. Insecure attachment styles may be related to mothers having lower social functioning (the SAS-SR domain assesses similar constructs such as the extent of engagement interest and neglect within social interactions), with being unable- or unwilling- to finding a partner, with greater affective psychopathology [4
], and with poorer parent–child interactions and parenting, and may explain why in our study children of single mothers who remitted tended to have worse outcomes than the children of remitting mothers in two-parent households.
Finally, there is also intriguing evidence in both primary and psychiatric medicine that patients with insecure attachment exhibit lower treatment adherence and poorer treatment outcome, and that this may be mediated by poorer interactions with their health care providers [11
]. Although the STAR*D trial may not be representative of regular patient-provider interactions, such factors could still plausibly account for the higher drop out rates among single mothers in our study. For instance, the single mothers may have been less communicative with or trusting of the STAR*D clinicians to provide care—a hallmark of dismissive attachment style [21
]—and thereby less invested in adhering to the treatment protocol or remaining enrolled in the study.
Our observation that the impact of the fathers is partially explained by the mothers’ social functioning is also important from an interventional perspective, as social functioning is a more therapeutically malleable target than marital or partnership status. Enrolling low-functioning and single depressed mothers in individual or group psychotherapies that target problems in social functioning by providing case management to deal with practical issues that occur in single-parent households may increase the chances of a positive outcome. This hypothesis is consonant with the studies of Miranda et al. [28
] and Lipman and Boyle [26
] who found that single or young minority women, when offered guideline-consistent care including case management and support, had better outcomes than with standard treatment (although Miranda’s study did not separate out single parents, 44% were unmarried). Furthermore, although STAR*D was not designed to study single motherhood per se, the overall demographics and lifetime clinical profiles of the single
mothers in our study are congruent with those found in previous epidemiologic studies of single-parent households [42
]. Because the design did not target single mothers in particular, however, the recruited sample encompassed women with a wide range of SES (e.g., of the full sample of 151 mothers at baseline, 26% were below the poverty line, and 19% had incomes above $60,000), race, geographical distribution, and treatment setting. This variation may help explain why previous interventions with low-income minority mothers (e.g., Miranda et al. [28
]) have reported difficulty in engaging patients in treatment. By being restricted to lower-income, minority, or single mothers, these studies may have in essence been capturing primarily a group at highest risk for non-remission.
One final note about the mothers’ treatment: although the STAR*D treatment design included non-pharmacological options, all
mothers represented in this report were on pharmacotherapy only (most were still on citalopram, the initial treatment in the STAR*D protocol) [33
]. Yet, their response to treatment was modulated by non-pharmacological variables such as social functioning. This finding is consistent with the growing body of evidence showing that psychopathological vulnerability is conferred by an interaction of multiple genetic and environmental factors [10
], and suggests that remission and recovery may be similarly dependent on such interactions.
The relation of fathers to child outcomes was more complex. Even though the association between maternal depression remission and improvement in children’s diagnoses was only found in two-parent families, this should be interpreted cautiously because a formal test of the interaction did not find the differences in odds ratios to reach statistical significance. If children in two-parent households indeed have better outcomes following their mother’s remission, this then suggests that having a father present may have a beneficial impact on child outcomes. This impact may be indirect, via the father facilitating the mother’s improvement, which in turn may have affected the children, or direct, that is fathers interacting with children in a manner that may have buffered the impact of the mother’s depression on her children. Importantly, the fathers who did not live in the household also had higher lifetime rates of substance use and incarceration. Their children, who themselves tended to have higher levels of externalizing disorders, may not only have lacked the positive environment conferred by a stable paternal presence, but also may have been further exposed to the negative impact of their father’s externalizing psychopathology. It also is possible that these children’s externalizing tendencies were the result of genes shared by them and their fathers or by the increased genetic loading from having two parents with psychopathology.
The literature dealing with fathers in general, and paternal depression in particular, is limited compared to that of mothers partly because depression is more prevalent in women, mothers are more likely to come for treatment, and following separation or divorce, most children live with their mothers [30
]. Despite these limitations, there is an emerging literature on the relation of paternal psychopathology to childhood disorders and development (see reviews by Connell and Goodman [13
], and Kane and Garber [22
]). Some studies have found that children who have two depressed parents are more vulnerable than children with a depressed mother only [6
]. In STAR*D-Child, fathers were not assessed directly. Information on their psychiatric history, which was obtained through the mothers, was thus limited and vulnerable to maternal reporting bias. We can not comprehensively address the role of paternal psychopathology in relation to maternal and child outcomes, and further studies with direct interviews of fathers (both biological and non-biological, resident and non-resident) alongside mothers and children are warranted.
Several additional limitations should be acknowledged. First, STAR*D Child examined only treatment-seeking depressed mothers and their children. It is unclear whether the findings would generalize to less severely depressed or to non-treatment seeking mothers, or to depressed fathers. Second, even though the father’s presence in the household was associated with maternal remission, we cannot rule out that if we had studied an alternative cohabiting adult—for e.g., a grandparent or friend—that we would not have found similar results. This is an intriguing hypothesis, and if future studies can replicate these effects with other non-paternal adults, this would have important social implications for intervention programs with single mothers. In either case, the current findings underscore the well-known difficulties for depressed mothers of raising children alone. Third, only a small number of possible explanatory factors were considered, as STAR*D was an effectiveness study, and nonessential measures were kept to a minimum. As detailed earlier, it is possible that other unmeasured characteristics of the mothers contributed to their likelihood of having a significant male relationship, their chances of remission from depression, as well as the level of their children’s psychopathology. A related limitation is that the findings of the present study are correlational. Given that it is not possible to randomly assign families to the presence or absence of a male in the house, such other variables cannot be ruled out, and thus, causal conclusions are not warranted at this time. Finally, our characterization of mother–child pairs does not account for past living circumstances, or for possible variation in involvement in the child’s life of fathers who were not part of the household.
Despite these limitations, this study holds significant clinical and public health implications. We have previously shown that when mothers achieve remission of their depression with medication, there is a concomitant positive change in their children as well. The present study showed that single depressed mothers did not fare as well as did those who had a residential male partner, and remission of their depression did not appear to be linked with significant change in their children. We have therefore identified a high-risk group of single-parent, socially impaired, depressed mothers, where the outcomes for the mothers and their children are less favorable, and who may require more targeted therapeutic strategies.