This small study had significant limitations, as described below. Nevertheless, data suggest that for depressed mothers whose children are receiving psychiatric treatment, psychotherapy specifically designed to meet their needs results in lower levels of symptoms and higher levels of functioning acutely and at the 9-month follow-up, compared to treatment as usual. In addition, this trial provides preliminary evidence for IPT-MOMS conferring benefit to offspring of depressed mothers, potentially mediated by change in maternal depression.
Recognizing that mothers of ill children rarely attend to their own needs and are, therefore, difficult to engage in treatment (5
), IPT-MOMS systematically incorporates strategies to increase the likelihood that subjects will attend sessions: IPT-MOMS therapists systematically explore and address psychological and practical barriers to treatment seeking (17
), and maternal sessions are coordinated with child sessions. The fact that mothers assigned to IPT-MOMS attended more treatment sessions over a 3-month period compared to mothers assigned to treatment as usual may contribute to the favorable outcomes seen in the IPT-MOMS group and may be an important finding, given the fact that this was predominantly a non-treatment-seeking population.
Although maternal improvement in symptoms and functioning was apparent at the 3-month follow-up, the positive impact of successful maternal treatment on child outcomes was not detectable until the 9-month follow-up. Clinically, we believe that effective IPT-MOMS treatment facilitates improvements in parenting skills, social support use, and management of ongoing interpersonal stressors. That the positive impact of maternal treatment was transmitted to the offspring in a delayed manner would support this hypothesis—i.e., first mothers heal themselves, and then they interact more effectively with their children. Clearly, larger trials will be needed to test this mediational hypothesis.
Our results compare favorably with STAR*D (10
), another study that looked at outcomes in offspring of mothers treated for depression. In both studies, offspring fared better when their mothers’ depression improved. Of interest, in the current trial, 61% (17 of 26) of the mothers initially assigned to IPT-MOMS remitted by the 3-month follow-up (defined as a HAM-D 17-item version score <8), compared with 25% (38 of 151) of the mothers enrolled in STAR*D (and 39% [11 of 21] of the mothers assigned to treatment as usual in the current trial). There are many differences between the two studies, including the fact that the STAR*D participants were treated with medication and not psychotherapy. One possible explanation for the relatively higher remission rates seen with the IPT-MOMS may be that a psychotherapy targeting the specific needs of depressed mothers with ill children may confer advantages beyond pharmacotherapy alone in this population. A properly designed trial would be required to formally test this hypothesis.
There are many limitations to this small study, and it should be replicated to confirm its findings. Most analyses focused on those completing the study, and yet 19% (nine of 47) of the maternal subjects dropped out by the 9-month follow-up, and up to 40% (19 of 47) of child assessments are missing for some measures. Data may not be missing at random. However, there were no differences in the percentages of missing data between the treatment groups at either follow-up assessment, suggesting these effects, even if biased, were similar across groups. In order to address this issue, we conducted secondary analyses of variables using mixed-effects models, techniques that use all available data on all enrolled subjects (36
), and found significant time-by-treatment interactions on measures of maternal functioning. There also appear to be tendencies toward interactions on maternal and child depression scores (), effects that might have reached statistical significance with larger groups.
The subjects assigned to treatment as usual had more anxiety disorder diagnoses at baseline, a clinical characteristic associated with worse outcomes over time (37
), which may account for observed differences in outcomes between groups. However, there were no differences in baseline levels of anxiety symptoms between groups as measured by the Beck Anxiety Inventory. More subjects assigned to IPT-MOMS were taking antidepressants at study entry than the subjects assigned to treatment as usual, but this number was not statistically significant. Notably, subjects entering the study while taking medication were taking stable doses of antidepressants for at least 8 weeks so that changes in symptoms observed subsequent to entry could be reasonably attributed to the intervention rather than to medications.
Because subjects assigned to IPT-MOMS attended more acute treatment sessions than those assigned to treatment as usual, it is impossible to determine whether favorable outcomes are simply a result of increased session frequency or session content. In addition, subjects in both groups received additional mental health services (both psychotherapy and pharmacotherapy) between 3-month and 9-month assessments, and we did not control for these services in our analyses. Of interest, significantly more treatment as usual than IPT-MOMS completers received treatment in the 3–9 month follow-up interval, and yet those assigned to IPT-MOMS fared better, suggesting enduring effects of acute treatment.
Child outcomes in this trial are considered preliminary because there were few exclusion criteria for children, and, therefore, they carried a wide range of diagnoses, were in different phases of their own treatment, and varied in age. The trial was not adequately powered to disentangle the differential effects of IPT-MOMS across these subgroups of children.
Despite its limitations, this study demonstrates that a high-risk population of non-treatment-seeking depressed mothers with psychiatrically ill offspring who received a brief psychosocial intervention had better outcomes at 3 and 9 months compared to those in treatment as usual. Those assigned to interpersonal psychotherapy MOMS stayed in treatment, achieved substantial clinical gains within a relatively short time, and stayed well over an additional 6 months. Their offspring also seemed to benefit from the mothers’ treatment. Future studies will be needed to replicate these results and to explore factors that mediate effects of maternal treatment outcomes on offspring.
“Ms. A,” age 38, suffered from major depressive disorder. She was the mother of “Ann,” a 14-year-old who was hospitalized 6 months earlier following an attempted overdose. In the engagement session, Ms. A articulated fears that admitting she was “depressed” meant that she was weak when she needed to be strong and that seeking therapy would selfishly take time away from her daughter. The therapist evoked Ms. A’s awareness of the discrepancy between her characteristic resilience and current inability to cope, describing depression as a no-fault illness whose treatment would facilitate return of her usual resourcefulness. The therapist also related interpersonal therapy’s emphasis on addressing interpersonal stressors, which led Ms. A to say that she needed guidance in dealing with Ann’s problems. The therapist explained that IPT-MOMS would specifically help Ms. A find ways to interact with Ann that would be more helpful to both mother and daughter. Ms. A explicitly agreed to eight sessions of psychotherapy in which the therapist would focus on Ms. A’s relationship with her daughter—in interpersonal therapy parlance, their nonreciprocal role expectations. Ms. A described worsening mood symptoms following an incident when Ann returned home from an outing with friends, visibly upset. Ms. A expected her daughter to confide in her about the night’s events, while Ann wanted to be left alone. An ensuing series of miscommunications resulted in Ms. A becoming frustrated and saying to her daughter, “I can’t stand your attitude.” Ann, in turn, became angry and yelled, “I’d rather kill myself than talk to you.” Ms. A was overwhelmed by conflicting feelings. She felt guilty about her comments to Ann and worried she had neglected warning signs of increasing suicidal ideation. She feared that her daughter might act on her threat. She also felt angry because she believed Ann was using her illness to manipulate her. The therapist discussed misaligned expectations around Ann’s social difficulties (should she share her feelings about them with her mother or not?) and constructive ways of discussing this core issue with her daughter. They used role playing to practice discussing the incident in a calm, constructive manner, i.e., stating directly how she both wanted to help Ann and felt frustrated when Ann shut her out. Ms. A was encouraged to relate her fears about Ann attempting suicide again when she appeared upset but refused to talk. Ms. A was given a homework assignment of talking to Ann about this issue. At the following session, Ms. A reported the conversation had gone well. Ann was receptive to Ms. A’s more direct style of communication. Ms. A, in turn, was open to her daughter’s request for more privacy. They felt closer to each other after the conversation, and Ms. A’s mood improved. Remaining sessions focused on refining communication between Ms. A and Ann in order to resolve the conflicts between them.