A Pilot Study of Interpersonal Psychotherapy for Depressed Women with Breast Cancer

Although depressive symptom prevalence varies by cancer site and stage, cancer patients have significantly greater likelihood of developing depression than the general population. Depression often worsens over the course of cancer treatment, persists long after cancer therapy ends, and worsens patients’ adherence to cancer treatment, survival, symptom management, and quality of life (Burgess et al., 2005). As surviving cancer becomes increasingly common, there is an urgent need to establish an empirical basis for providing evidence-based treatments to depressed cancer patients.

A difficulty in providing evidence-based treatment for major depressive disorder (MDD) among cancer patients is that clinical trials for MDD systematically exclude patients with cancer and other medical illnesses, precluding generalizability of those studies to these special populations (Blanco et al., 2008). Furthermore, although several studies have examined the effects of medication and psychotherapy among cancer patients (Grassi, Nanni, Uchitomi, & Riba, 2011; Kissane, Levin, Hales, Lo, & Rodin, 2011), most of those studies were preventive, selecting subjects on the basis of a cancer diagnosis rather than psychiatric diagnoses. Hence little is known about effective approaches for the treatment of depression among cancer patients.

We sought to narrow that gap in knowledge by conducting an open, pilot study of interpersonal psychotherapy (IPT) for depressed women with breast cancer. The goals of this proof-of-concept study were to examine the feasibility and preliminary efficacy of IPT in decreasing depressive symptoms and improving quality of life in this population. We chose IPT for this study because of its focus on life events (such as the diagnosis of cancer) and its extensive support in the treatment of MDD in the general population, among patients with comorbid medical illnesses. and for patients whose declining physical health led to more dependent and strained relationships (Weissman, Markowitz, & Klerman, 2000).

Seven patients, all female, participated in the study. Five (71%) patients were Hispanic, the other two (29%) were African American. The participants’ mean age was 49.0 (SD= 8.1; range 42-63). Two patients (29%) were married. Most patients (71%) had incomes below $10,000 per year. All outcome measures indicated a significant improvement during the study (Table 1). The HAM-D decreased from 21.3 (SD=8.1) to 11.1 (9.6) (t=3.3, df=6, p=0.02) with a Cohen’s d=1.06 (very large effect size); the BDI-II decreased from 26.1 (11.2) to 15.0 (11.9) (t=3.3, df=6, p=0.02) with a Cohen’s d=.93. Both scales showed linear decreases over time. The HAM-A fell from 22.7 (6.0) to 17.1 (10.9) (t=2.2, df=6, p=0.07), approaching but not achieving statistical significance. The GAF improved from 56.7 (5.5) to 70.3 (15.6) (t=2.5, df=6, p=0.049), Cohen’s d=0.87. A mixed regression model indicated that change in HAM-D scores predicted change in GAF scores (F_1,3 = 17.7, p=0.03). The mean CGI at endpoint was 2 (1.4), in the Much Improved range.

In this proof-of-concept study for the treatment of MDD among women with breast cancer, IPT was associated with large improvements across all standardized outcome measures, regardless of whether clinician-administered or self-report or if they measured symptomatic or functional improvement. Furthermore, improvement in depressive symptoms mediated marked functional improvement scores.

Our findings of improved depressive symptoms among women with breast cancer and MDD treated with IPT are consistent with findings from prior studies that have shown that IPT can be efficacious in depressed individuals with medical illness (Weissman et al., 2000). The robustness of the change was indicated by its consistency across measures, types of test (parametric and non-parametric), and in large effect sizes. The efficacy of IPT for depressed individuals with medical illness, including breast cancer, may stem from its ability to help patients address the life events and changes in interpersonal relationships often associated with depression. The diagnosis of breast cancer represents an important change in one’s life that the IPT framework of a role transition neatly encompasses. In this transition, interpersonal relationships as well as the individual’s self-image often change. An important goal of IPT is to help the patient recognize the impact of the change on her mood and life, and to help her clarify and express her expectations, needs, and capabilities in her relationships so that they can continue to be satisfying and supportive. Interpersonal psychotherapy helps patients to mobilize social support that relieves depressive symptoms and bolsters patients in a life crisis. On occasion, patients may benefit from establishing new relationships that can help them address new needs, or limiting contact with friends or acquaintances that may represent an extra demand, rather than help, during this transition.

In addition to relieving depressive symptoms, IPT produced functional improvement, partially via improvement in depressive symptoms. The finding of functional improvement is important because while clinicians often focus on symptomatic improvement, patients often care more about their overall level of functioning. Consistent with this view, functional improvement was not fully mediated by improvement in depressive symptoms, suggesting that the effects of IPT on other aspects of the patients’ lives (e.g., quality of interpersonal relationships, or finding a meaning in one’s life in crisis) may extend beyond its effect on mood. An important direction for future research is to examine whether treatments such as antidepressant medication that exclusively target symptomatic improvement can produce the same level of functional improvement as psychotherapies, which target broader outcome areas, and whether they have the same level of acceptability. It is not uncommon for depressed breast cancer patients to be reluctant to take additional medications, such as antidepressants (Grassi et al., 2011).

As with many pilot trials, the main limitation of this study is that did not include a comparison group. Therefore, the improvements documented may be due to non-specific effects of the therapy or of the study context itself. The large effect sizes detected, however, suggest that psychotherapeutic interventions can help to improve depressive symptoms among depressed women with breast cancer, and they indicate that a diagnosis of cancer does not have to be accompanied by depression. These results support the need for randomized trials to examine the efficacy of IPT versus those of other psychotherapies.

In summary, this preliminary trial found IPT a powerful treatment for depression among women with breast cancer. Patients reported both symptomatic and functional improvement, and are associated with large effect sizes. We hope these data may contribute to establishing a growing evidence base for the treatment of depressed women with breast cancer, and stimulate other researchers to conduct studies to improve the treatment of this important, but often neglected population/treatment aspect.

Supported in part by NIH grant CA133050 and DA023200, and the New York State Psychiatric Institute (Drs. Blanco and Markowitz).

Conflict of Interest: None of the authors reports any conflict of interest.