Brief Interpersonal Psychotherapy (IPT-B): Overview and Review of Evidence

Introduction

Depression is a prevalent illness, affecting 16% of individuals over their lifetime (Kessler et al., 2003). However, less than a third of individuals suffering from depression will receive treatment for the disorder (Kessler et al., 2005), and even fewer will receive adequate treatment. In the National Comorbidity replication study Survey (Wang et al., 2005), approximately 40% of respondents with a psychiatric disorder received behavioral health care over a 12-month period, but the number of visits was small: patients treated in the mental health specialty sector received approximately seven visits over the year. Time-limited psychotherapies for depression are typically administered over 12 to 20 sessions (Koss & Shiang, 1994) with the primary goal of symptom remission. Although brief by psychoanalytic standards, even these time-limited treatments may be impractical in routine practice settings where the fiscal constraints of public health care systems, limited availability of trained mental health providers, and low-reimbursement rates for psychotherapeutic services constrain delivery of longer term treatments (Clemens, 2009). Thus, shorter duration treatments, if effective, may better meet the needs of individuals unable to access more time-intensive services.

Little is known about optimal dosage of psychotherapy. A meta-analysis of a large sample of individuals (n = 2,431) pooled from numerous psychotherapy studies found that half of the patients studied achieved symptom relief within eight sessions of open-ended treatment (Howard, Kopta, Krause, & Orlinsky, 1986). Although most studies evaluated in this meta-analysis were naturalistic and included patients suffering from heterogeneous symptoms (diagnoses not specified), this finding raises the possibility that for many patients, eight sessions may be adequate. A randomized study from the United Kingdom compared eight and 16 sessions of two manual-based treatments for depression, cognitive behavior therapy and psychodynamic-interpersonal therapy (not to be confused with interpersonal psychotherapy or IPT), and found no long-term advantage of 16 sessions over eight sessions for either modality (Shapiro et al., 1994). For those who were more severely depressed, 16 sessions were initially associated with better outcomes than eight, but this advantage disappeared when patients were reassessed at one-year follow up (Shapiro et al., 1995).

Although it may seem counterintuitive to believe that patients could achieve the same degree of relief from eight and 16 sessions of therapy, investigations have shown that when the number of therapy sessions is limited from the outset, patients and therapists felt pressured to make more efficient use of psychotherapy. That is, patients who know a priori that a treatment will conclude in eight weeks behave differently over time—move faster—than those assigned to a psychotherapy that is expected to continue for 16 weeks (Barkham, Rees, Stiles, Hardy, & Shapiro, 2002; Reynolds, Stiles, Barkham, & Shapiro, 1996). Thus, the expectation of treatment brevity spurs both patients and therapists to work harder and faster.

Rationale for Development of Brief Interpersonal Psychotherapy (IPT-B)

Interpersonal psychotherapy (IPT) is an evidence-based psychotherapy for depression (Cuijpers et al., 2011) that, like many time-limited therapies, was originally designed to be administered as a 12-to-16 week intervention (Klerman, Weissman, Rounsaville, & Chevron, 1984). The rationale for developing a briefer form of IPT was two-fold. As outlined above, a paucity of empirical evidence linking increased therapy “dosage” to enhanced therapeutic effects raised the possibility of achieving favorable outcomes with a more limited number of psychotherapy sessions. Also, some depressed individuals are unable to attend 16 sessions of psychotherapy, even when it is offered free of charge and in a convenient location (Swartz et al., 2002). We, therefore, set out to develop an eight-session version of IPT that would offer the dual advantages of rapid relief from suffering and decreased resource utilization. We reasoned that this approach would be especially useful for treating individuals with constrained capacity to participate in longer courses of therapy because of limited access to care or difficulty engaging in longer-term treatment.

When we developed IPT-B, a very short form of IPT called Interpersonal Counseling (IPC) had already been described. In its original iteration, six-session IPC was designed to treat distress (not depression) in primary care patients with subsyndromal psychiatric diagnoses (Klerman & Weissman, 1993). Interpersonal Counseling is simplified for administration by non-mental health professionals. (See Weissman et al., in this issue, for an update on IPC.) We, however, were providing treatment for syndromally depressed individuals, many of whom did not seek treatment and were socioeconomically disadvantaged (see below). In order to meet the needs of our patients who were both very symptomatic and unlikely to adhere to a longer course of IPT, we, therefore, sought to develop an intervention more intensive than IPC that was provided by mental health professionals and delivered in a shorter period of time than full-length IPT In this review, we provide an overview of IPT-B and describe the modifications made to standard IPT (Weissman, Markowitz, & Klerman, 2000) to meet the needs of the truncated time course. We then review the extant empirical evidence base testing this briefer model of IPT.

Overview of Brief Interpersonal Psychotherapy (IPT-B)

Brief Interpersonal Psychotherapy consists of eight psychotherapy sessions, each lasting 45-to-60 minutes, delivered by a professional therapist trained in IPT—physician, psychologist, nurse, or social worker (the authors (Swartz, Grote, et al., 2004) will provide an unpublished treatment manual upon request). Brief Interpersonal Psychotherapy is often—but not always—administered in conjunction with a single engagement session, which is summarized below (for a detailed description see Swartz et al., 2007; Zuckoff, Swartz, & Grote, 2008). Although sessions are typically scheduled weekly, patients are permitted 12 to 14 weeks to complete all eight sessions. Because an important goal of IPT-B is to improve access, most research studies have permitted telephone sessions in place of a limited number of face-to-face sessions, but regulatory requirements may limit this practice in clinical settings. As in standard IPT, IPT-B is a therapy of change, and the time limit is a crucial element in this process (Swartz & Markowitz, 1998). Because the therapist makes the duration of treatment explicit from the outset, time limitation is an important motivational force in activating the therapist and for encouraging the patient toward change. Brief Interpersonal Psychotherapy intensifies the concept of time as leverage. Both therapist and patient attend to the figurative “ticking clock”. Therapists explicitly acknowledge the session number at each visit. In IPT-B, the therapist carefully balances a sense of urgency with attention to protecting the patient from feeling overwhelmed or a failure. While, IPT-B retains the structure of standard IPT, it also employs a series of strategies to distill the therapies most important ingredients and hasten its time course. Table 1 compares standard IPT to IPT-B.

Initial Phase Modifications

In IPT-B, the initial phase of treatment is limited to two (rather than a maximum of three in conventional IPT) sessions. The main goal of the initial phase remains case formulation. Because of time constraints, however, IPT-B therapists must somewhat constrict the interpersonal inventory, the careful review of important interpersonal relationships that is a central component of IPT. The therapist collects basic information about the family of origin but does not dwell on these relationships unless they clearly relate to the current depressive episode. Similarly, the therapist relies on patients to identify the most important people in their lives, focusing on these relationships in the time available. Although it is possible that the therapist will miss an important covert dispute when truncating the interpersonal inventory, these instances are rare.

Treatment is hastened by making a provisional case formulation at the end of the first session. This represents the therapist’s “best guess” about what is likely to be a reasonable focus of treatment. It forces the therapist to focus even in the first session, and it acculturates the patient to the pace of IPT-B. In the first session, the therapist specifically asks the patient to think about what she would like to work on in therapy (this is the homework assignment for session one). In the second session, the therapist continues to collect information (including the patient’s goals for treatment), allowing her to refine the formulation and revisit the problem area choice if necessary. By the end of the second session, the therapist offers a revised case formulation to the patient. This case formulation follows the format used for all IPT cases (Markowitz & Swartz, 2007). If acceptable to and explicitly agreed upon by both parties, a finalized case formulation signals the end of the initial phase.

In IPT-B, the therapist seeks a treatment focus that can be resolved in eight sessions by building on a patient’s existing strengths rather than attempting to correct longstanding interpersonal problems. The brevity of IPT-B makes it more likely that a patient will experience mastery if the therapist leverages areas of intact functioning rather than attempting to correct longstanding dysfunctional interpersonal relationship patterns. Therefore, therapists avoid making very volatile situations, such as entrenched abusive relationships, the focus of treatment as that would likely take more than eight sessions to sort out. However, patient abuse would be addressed to the extent needed to ensure patient safety and to identify additional resources, such as abuse hotlines that could be used to adjunctively to IPT-B. Therapists using IPT-B especially avoid interpersonal deficits, the non-life-event category of last resort in standard IPT, because eight sessions do not provide adequate time to work with individuals for whom deficits is the sole focus of treatment. Interpersonal deficits are used as the focus of treatment when patients describes longstanding impoverished or contentious relationships but cannot identify a current interpersonal event, such as grief or an acute interpersonal conflict that might better serve as the treatment focus. These individuals may be better served by a longer course of IPT or another kind of treatment (Sotsky et al., 1991).

Increased Patient Responsibility and Activation

In IPT-B, patients are encouraged to play an even more active role in the therapeutic process than in standard IPT. By stressing the time limit, the therapist continually urges the patient to take risks and make changes in the time available. Although encouragement to make rapid changes is part of standard IPT, in IPT-B the process is intensified and emphasized because of the foreshortened time course. Therapists ask patients to identify treatment goals in the first session, to make an explicit commitment to change, even while acknowledging their feelings of despair and helplessness (“That’s part of the depression”). The tension between pushing patients to change and maintaining an empathic stance toward depressive symptoms is especially pronounced. The IPT-B therapist asks the patient to carry out weekly interpersonal homework assignments to facilitate the change process. These are not written assignments but exercises therapist and patient collaboratively develop to help resolve the focal interpersonal problem. Typical homework assignments might include discussing a conflict-laden issue with a partner, exploring part-time job opportunities, or enrolling in a parenting class.

IPT-B uses strategies resembling behavioral activation (BA) (Jacobson, Martell, & Dimidjian, 2001) to encourage patient activation, especially in the first few sessions. In BA, which was developed after and independently from IPT, the therapist develops graded task assignments to increase the chance that patients will engage in pleasurable (positively reinforced) activities. Both IPT-B and standard IPT therapists employ a set of strategies designed to increase activation. These strategies are convergent with, but not derived, from BA. In the context of assessing the depression, the IPT therapist determines the extent of the patient’s withdrawal from previously gratifying relationships and activities and inquires about the effect of the depression on participation in these activities. The therapist using IPT-B moves rapidly to explore potential avenues to help the patient re-engage, often working on these tasks before addressing the complexities of the interpersonal problem area. For instance, the therapist may spend half a session exploring barriers to the patient’s participating in previously pleasurable activities, such as gardening or quilting, before working on resolving the patient’s conflict with a spouse. Because of IPT-B’s time constraints, achieving rapidly a small amount of relief from depression (presumably by re-engaging in pleasurable activities) makes it easier for the patient to undertake the more challenging tasks required to resolve their interpersonal problems in eight sessions. The therapist explores barriers to involvement in pleasurable activities and discusses the role of depression in limiting participation in these activities. The therapist uses a graded approach (as in cognitive therapy) based on the extent of the patient’s anergia to encourage re-engagement but makes no specific effort to monitor the patient’s daily activities.

Rapid Termination Phase

The time constraints of IPT-B mean termination is never far from the minds of the patient and the therapist. Termination is addressed over the course of a single session, which limits the therapist’s ability to process the patient’s emotional responses (such as sadness or anger) to treatment ending. Most of the concluding session comprises a review of treatment gains, identification of unaddressed problems, and discussion of warning signs of recurrence. For some individuals, IPT-B will be a prelude to a longer course of therapy or introduction to another type of mental health treatment; for others, IPT-B will constitute their entire treatment experience. In either case, it is important for the patient to finish IPT-B with a sense of accomplishment and feeling of mastery.

IPT-B Therapist Training

Therapists testing IPT-B in randomized controlled trials conduct at least two supervised cases prior to treating patients in the studies. Some have had prior experience with standard IPT; others have not. Therapists with prior IPT training have the advantage of already knowing IPT strategies and techniques but feel much pressure to complete in eight sessions what they are used to doing in 12 to 16 sessions. Advanced training in IPT-B focuses on identifying key (versus nonessential) components of the interpersonal inventory, speeding up the case formulation process, initiating behavioral activation strategies very early in treatment, developing appropriate homework assignments, and managing the tension between pushing the patient toward rapid change and maintaining a supportive stance. Therapists without prior IPT-B training are not usually as concerned by the truncated time limit as seasoned IPT therapists, but they face the challenge of moving swiftly through a treatment modality that is unfamiliar to them. An additional training case is sometimes needed for adequate mastery of the material. Brief Interpersonal Psychotherapy generally comes more easily to those who are comfortable with an active stance, enjoy working in challenging settings, and have the capacity to maintain treatment focus even in the face of multiple distractions.

Summary of Engagement Session

In many cases, we offer a single engagement session prior to the first IPT-B session (Grote, Zuckoff, Swartz, Bledsoe, & Geibel, 2007; Swartz, et al., 2007; Zuckoff, et al., 2008). The engagement session, based on principles of motivational interviewing ([MI] Miller & Rollnick, 2002) and ethnographic interviewing ((EI] Schensul, Schensul, & LeCompte, 1999), explores practical, psychological, and cultural barriers to depression treatment. It assumes that patients will be more receptive to psychoeducation and treatment recommendations when therapists communicate an understanding of the patients’ individual and culturally-embedded needs, perspectives, and experiences. Under these circumstances, therapists are able to help patients see how the potential benefits of IPT-B align with their own priorities and concerns, to facilitate a process of identifying and resolving ambivalence, and to problem-solve barriers to treatment engagement. The EI component of the engagement session encourages therapists to be aware of their own unconscious biases—and ultimately suspend them—in order to attend to cultural issues that may affect patient attitudes toward therapy. The MI component uses client-centered techniques such as open-ended questions, affirmation, reflective listening, and summarizing ([“OARS”] Zuckoff, et al., 2008) to promote an understanding of the patient’s concerns while developing discrepancy between the patient’s current behavior and her cherished goals or values. Motivational inter-viewing techniques are also used to build awareness of the importance of change and highlight intrinsic motivation to change.

The five components of the engagement session include:

The engagement session “jump starts” IPT-B by helping the patient to articulate her primary concerns, identify issues (practical, psychological and cultural) that may interfere with treatment adherence, and commit to IPT-B. Techniques derived from the engagement session can be used in subsequent IPT-B sessions as well, if needed. For instance, if a patient expresses ambivalence about making the changes in relationships as required by IPT-B, the therapist may use MI techniques to help overcome barriers to treatment progress. For example, the therapist may employ double-side reflections (“on one hand, you are very eager to be on more equal footing with your husband; on the other hand, it is very hard to stand up to him for the things you want”) or agreement with a twist (“standing up to your husband would be impossible because he would probably kick you out of the house if you did”). We have found that this approach is very compatible with IPT-B.

Review of Efficacy Data

Table 2 summarizes the evidence base supporting the efficacy of IPT-B. Its first test was a matched-case control eight week study comparing IPT-B (n=16) to sertraline (n=16) as treatment for women who met DSM-IV criteria for major depressive disorder (MDD). Mean dose of sertraline at week 8 was 134.4±35.2 mg/day (Swartz, Frank, et al., 2004). Seventy-six percent (13/16) of the women who received IPT-B completed all eight treatment sessions. Mean number of sessions completed was 7.1 (± 2.0). During the eight weeks, both groups improved. The Hamilton Rating Scale for Depression ([HRSD] Hamilton, 1960) showed a significant time by group interaction (F=4.76, df=1, 161, p = .03) indicating that the group receiving IPT-B improved more quickly than the sertraline-treated group. Although effect sizes were robust for both groups, the IPT-B was associated with somewhat greater effects than sertraline: an effect size of 1.9 compared with 1.7 for HRSD scores and 1.9 compared with 1.4 for Global Assessment Scale (GAS) scores (Swartz, Frank, et al., 2004).

IPT-B for Depressed Mothers of Children with Psychiatric Illness

Depressed mothers of children with psychiatric illness were identified as a group likely to benefit from a brief psychotherapy. Many mothers are overwhelmed by the competing demands of parenting an ill child and seeking treatment for themselves, and relatively few engage in mental health services for themselves, even when they bring their child for care (Swartz et al., 2005). Further, maternal depression constitutes an important risk factor for childhood psychiatric illness (Lewis, Collishaw, Harold, Rice, & Thapar, 2011; Lewis, Rice, Harold, Collishaw, & Thapar, 2011; Tully, Iacono, & McGue, 2008) and has a negative impact on child psychiatric outcomes, even among children who are treated (Brent et al., 1998; Garber et al., 2009). Open pilot testing of IPT-B (n=13), used in combination with a single engagement session (Swartz, et al., 2007), demonstrated the feasibility of treating depressed mothers of psychiatrically ill children ages 12 to 18 years for MDD. Mean HRSD score at entry to the study was 20.9 (±3.7). Thirty-eight percent (5/13) were on psychotropic medication at study entry, but medication and dosages were held constant during the treatment protocol. All mothers who participated in the engagement session (n=11) attended at least one IPT-B session (mean, 7.9), and most (10/11) completed eight sessions. The mean improvement on the HRSD was 11.3 points (±10.4) with a Cohen’s d effect size of 1.09 (Swartz et al., 2006).

A larger study compared IPT-B (n=26) to treatment as usual (TAU; n=21) as treatment for MDD in mothers of children ages 6-18 years who were receiving treatment for a psychiatric disorder. Brief Interpersonal Psychotherapy, again administered in combination with a single engagement session (Swartz, et al., 2007), was modified to include a new focus on “parenting an ill child” as a subtype of a role transition. Children were treated openly in the community (treatment was not provided by the research study), and mothers were recruited through the clinics at which their children were receiving services. When possible, maternal treatment was provided at the same time and in the same setting as their child’s mental health services. Seven mothers assigned to IPT-B and three assigned to TAU were taking antidepressant medications at baseline, but this difference was not statistically significant. Pharmacotherapy remained constant from baseline through the 3-month assessment for those assigned to IPT-B in accordance with the requirements of the protocol. Mean baseline HRSD scores in the IPT-B and TAU groups were 20.7 (± 4.4) and 22.4 (± 4.2), respectively. Controlling for baseline values, analyses of covariance comparing mean maternal symptom and functioning scores at 3- and 9-month follow-ups found significantly better outcomes in the IPT-B group than TAU on HRSD scores at 3 months [F=6.36, df = 1, 39, p <0.02] and 9 months [F= 8.36, df = 1, 35, p=0.007] and Global Assessment of Functioning scores (American Psychiatric Association, 1994) at 3 months [F=5.57, df=1, 39, p <0.03] and 9 months [F= 7.28, df = 1, 35, p<0.02]. At 9-month follow up, with the addition of control for baseline values, children of mothers treated with IPT-B had significantly better child self-report depression and functioning scores than those whose mothers received TAU (as measured by the Children’s Depression Inventory; Kovacs, 1992) [F = 14.61, df=1,24, p= 0.001] and the Columbia Impairment Scale (Bird et al., 1993) [F=5.25, df = 1,24, p=0.003]. Although many studies have shown that maternal depression is associated with poor child outcomes (England & Sim, 2009), this was the first study to demonstrate that treating maternal depression with psychotherapy has a positive impact on psychiatrically ill offspring (Swartz et al., 2008).

IPT-B for Perinatal Depression

Depression during pregnancy is one of the strongest predictors of postpartum depression, which in turn has lasting, deleterious effects on infant and child well-being and on the mother’s and father’s mental health. However, childbearing women with depression, especially those who are socioeconomically disadvantaged, have proven difficult to engage and retain in adequate mental health treatment (Miranda et al., 2003). To minimize barriers to care, ameliorate antenatal depression, and prevent postpartum depression, Grote and colleagues (2004) conducted an open trial of acute IPT-B during pregnancy and before childbirth (n=12), in combination with a pre-treatment engagement session (Swartz, et al., 2007) and followed by monthly IPT maintenance sessions up to 6 months postpartum. Findings demonstrated the feasibility of treating depressed, pregnant women on low incomes who were receiving prenatal services in a large, urban obstetrics and gynecology Ob/Gyn clinic and who were not on pharmacotherapy or receiving other psychosocial treatments. Baseline mean Edinburgh Postnatal Depression Scale ([EPDS] Cox, Holden, & Sagovsky, 1987) score was 16.1 (±7.6). All 12 patients who participated in the engagement session attended at least one IPT-B session and nine patients (75%) completed eight sessions of IPT-B (overall mean number of sessions attended=6.25). At post-treatment, mean EPDS score was 3.2 (±2.4); at 6 months postpartum mean EPDS score was 5.7 (±7.2). Intent-to-treat analyses (using paired t tests and the more conservative Wilcoxon Signed Rank test) showed that study enrollees experienced a significant reduction in depressive symptoms on the Edinburgh Postnatal Depression Scale (EPDS) (Cox, et al., 1987) by the end of acute IPT-B treatment t (11) = 4.0, p < .01 and W= −2.8, p < .01 (effect size = 1.2) and at 6 months postpartum t(11) = 2.9, p < .05 and W = −2.3,p < .05 (effect size=.8). Participants rated their treatment satisfaction high at both follow-up time points (Grote, Bledsoe, Swartz, & Frank, 2004b).

A larger study subsequently tested IPT-B in treating antenatal depression in socio-economically disadvantaged women. Once again, IPT-B involved a multicomponent model of care consisting of a pre-treatment engagement session (Grote, et al., 2007), acute IPT-B before childbirth, and monthly maintenance IPT up to six months postpartum. Fifty-three non-treatment-seeking, pregnant women not receiving any form of depression care were randomly assigned to receive either IPT-B (n=25) or enhanced usual care (UC; n=28), both conditions delivered in a large, urban Ob/Gyn clinic. In a large, urban obstetrics and gynecology clinic, 53 women who were pregnant and not receiving any form of care for depression were randomly assigned to receive either IPT-B (n=25) or enhanced usual care (UC; n=28) which consisted of a referral for mental health services in a clinic that was co-located in the same hospital as the obstetrics clinic. Interventionists using IPT-B assisted participants in meeting their basic needs by integrating case management services into the IPT-B sessions. Ninety-six percent of the IPT-B group (n=24) attended at least one treatment session, compared to 36% of the UC group (n = 10), and 68% (n=17) of the IPT-B group completed 7 to 8 IPT-B sessions (defined as a full course of treatment), compared to 7% in the UC group (n=2). Intent-to-treat analyses showed that participants in IPT-B, relative to those in UC, displayed significant reductions in depression diagnoses both before childbirth and at 6 months postpartum (effect sizes = .96; 1.22, respectively) and reported fewer depressive symptoms (effect sizes = .71; .89, respectively) (Grote et al., 2009).

Other Adaptations of IPT-B and Related Brief Treatments

Poleshuck and colleagues (2010) adapted IPT-B as a treatment for women with co-occurring depression and chronic pain (Poleshuck, Gamble, et al., 2010). Interpersonal Psychotherapy for Depression and Pain (IPT-P) uses IPT-B as its core structure but incorporates components of pain management, including an evaluation of pain intensity and interference. Interpersonal Psychotherapy for Depression and Pain was developed to meet the needs of predominantly low income women with chronic pelvic pain. Sessions were held in an urban obstetrics and gynecology clinic that provided a weekly specialty clinic focused on chronic pelvic pain. An open study of IPT-P (n=17) treated women with MDD and who experienced at least 3 months of self-reported pelvic pain. Treatment was delivered over a period of up to 36 weeks. Mean baseline HRSD score was 20.2 (± 4.9). Generalized estimating equations found statistically significant declines in HRSD and Social Adjustment Scale ([SAS] Weissman & Bothwell, 1976) scores over time, with large effect sizes (HRSD= 1.57, SAS= 0.96). No significant change in Multidimensional Pain Inventory (Kerns, Turk, & Rudy, 1985) pain interference scores were observed (Poleshuck, Talbot, et al., 2010).

Consistent with the aims of IPT-B for perinatal depression (Grote, Bledsoe, Swartz, & Frank, 2004a), Brandon and colleagues developed a conjoint form of treatment, partner-assisted IPT (PA-IPT) for depressed women who were pregnant or immediately post-partum. Retaining the 8-session treatment framework, PA-IPT includes a partner as an active participant throughout the treatment. The intervention incorporates elements of Emotionally Focused Couples Therapy to strengthen the couple’s interpersonal bond and to address attachment needs within the context of the transition to parenthood. Investigators conducted an open study (n=10) of PA-IPT consisting of 8 acute sessions delivered over 12 weeks. Mean baseline HRSD score was 19.1 (± 6.1). Ninety percent of women had HRSD scores ≤9 at the end of acute treatment, with a mean HRSD score of 6.0 (± 4.5). EPDS scores showed statistically significant declines over time (p <0.05). The Dyadic Adjustment Scale (Spanier, 1976) revealed no statistically significant changes in relationship satisfaction. The investigators report low drop-out rates with 100 percent (10/10) of enrolled couples competing treatment. Anecdotal reports of treatment satisfaction among participants were high (Brandon et al., 2012).

In parallel to the version of IPT-B used in the United States, clinical investigators in Scotland developed an 8-session version of IPT. The two treatments are very similar, although they were developed independently. Pilot testing of IPT-B (Scotland) was conducted in primary care settings. Individuals with a clinical diagnosis of MDD were randomly assigned to either IPT-B (n=26) or a waiting list control group (WLC; n=23). Mean baseline HRSD scores were 17.9 (± 6.6) and 17.4 (± 6.6) in the IPT-B and WLC groups, respectively. Mixed factorial repeated measures ANOVA demonstrated that IPT-B yielded a significantly greater reduction of symptoms of depression as measured by the HRSD (p<0.01) and Beck Depression Inventory ([BDI-II] Beck, Steer, & Brown, 1996) (p<0.01) in patients assigned to IPT-B versus WLC. Initial severity of depression symptoms predicted reliable change and outcome. Seventy three percent (19/26) of patients assigned to IPT-B experienced significant change by two-month follow up using Jacobson’s criteria for clinically meaningful change (Jacobson & Truax, 1991) with a NNT <1. Assignment to IPT-B was not associated with significantly different improvement from WLC in the quality of interpersonal relationships measured by the Significant Others Scale (Power, Champion, & Aris, 1988) over the short duration of treatment or two-month follow-up. Secondary analyses demonstrated that higher (worse) BDI-II depression scores at baseline were associated with greater improvement in IPT-B (Graham, 2006).

Discussion

Although psychotherapy often provides a place for reflection and exploration, it cannot escape the economic and organizational pressures that drive all technologies to greater efficiency. Limited therapist availability, long waiting lists, and inadequate insurance benefits restrict the number of psychotherapy sessions available to many patients (Clemens, 2009). Patients, in turn, may have limited time, energy, or finances available to devote to psychotherapy, or may face obstacles in accessing it (Greeno et al., 2002; Grote, et al., 2007; Maynard, Ehreth, Cox, Peterson, & McGann, 1997; Scholle, Haskett, Hanusa, & Kupfer, 2003). The goal of IPT-B is to allow individuals who are unlikely to attend 16 sessions of psychotherapy—because of external or internal constraints–to get the benefits of “full strength” IPT in fewer sessions.

Brief Interpersonal Psychotherapy initially was developed and tested in individuals considered unlikely to access a full course of IPT because of ambivalence about treatment seeking or limited access to care. The first trials of IPT-B focused on depressed mothers of psychiatrically ill children and on economically disadvantaged pregnant women. Many of these individuals were not seeking treatment, had limited financial resources, and had very chaotic lives. The goal, therefore, was to help those who would not otherwise receive “full strength” IPT to access a coherent treatment in fewer sessions. Initially, clinicians were concerned that IPT-B would be appropriate only for those individuals with modest symptoms and relatively few interpersonal stressors. Despite these initial reservations, we found that the intensity of focus in IPT-B is very helpful for patients with a multitude of interpersonal problems. Its structure forces patients (and therapists) to choose the most pressing—and (hopefully) solvable—interpersonal problem as the fulcrum of the treatment which provides a sense of purpose and organization in the midst of the chaos. We readily acknowledge that IPT-B is not a panacea. Some graduates of IPT-B unsurprisingly require additional treatment. In one study, 60% (13/22) of those completing IPT-B reported receiving follow-up mental health treatment (Swartz, et al., 2008). Brief Interpersonal Psychotherapy, therefore, also functions as a treatment “sieve,” determining for whom more intensive services are indicated or eight sessions will suffice. We consider a willingness to accept a referral for additional psychotherapy or a course of medication, if indicated, a “good” outcome of IPT-B.

Smaller studies have begun to explore IPT-B’s role as a treatment for depression and comorbid pain, as a conjoint treatment for perinatal depression, and as a treatment for depression in primary care. The growing evidence for IPT-B parallels the growing need in routine practice settings to find ways to deliver evidence-based treatments utilizing fewer resources. Not surprisingly, several large health care provider organizations have expressed interest in IPT-B as a way of delivering services to more depressed patients in a shorter period of time and with fewer therapist hours. For instance, IPT-B is currently being used in England as part of Improving Access to Psychological Therapies (IAPT) in the National Health Service to deliver an evidence-based psychotherapy while maintaining outcome standards (R. Law, personal communication, 2013). These applications of IPT-B hint at its broader applicability, but additional testing is required to evaluate its efficacy in a general depressed population and to evaluate its effectiveness on a larger scale.

IPT-B remains a fruitful area for future study. Optimal dosage of IPT remains an unanswered question. “Dose ranging” studies examining variably dosed IPT would be an important next step in defining the best dose—or doses—of IPT for specific disorders and populations. Although we have explored this issue in the maintenance phase of depression treatment (Frank et al., 2007), dosage of IPT for acute depression has not yet been systematically examined. In addition, larger studies examining methods for implementing IPT-B in routine practice settings would help to address global concerns about an insufficient mental health workforce as well as the ability of that workforce to deliver effective interventions with sufficient fidelity to achieve a clinically meaningful impact.