Michael J. Constantino, PhD

Major depressive disorder (MDD) frequently is recur­rent, with new episodes causing substantial social and economic impairment¹ and increasing the like­lihood of future episodes.² For this reason, contemporary psychiatric practitioners think of depression treatment as long-term and plan thoughtfully for maintenance therapy.

Recognizing the importance of engaging depressed indi­viduals beyond the initial response,³ American Psychiatric Association practice guidelines conceptualize depression treatment as 3 phases:
   • acute treatment, with the aim of remission (symptom removal)
   • continuation treatment, with the aim of preventing re­lapse (symptom return)
   • maintenance treatment, with the aim of preventing re­currence (new episodes).⁴
Interpersonal psychotherapy (IPT) is an evidence-based psychosocial treatment that adheres to this model.⁵ As a time-limited, manual-driven^6,7 approach, IPT focuses on interpersonal distresses as precipitating and perpetuating factors of depression.⁸

Acute IPT’s efficacy is well-established across >200 empirical studies—making it an evidence-based, first-line treatment for adult depression.^4,9,10 Meta-analyses show that acute IPT is superior to placebo and no-treatment con­trols, and largely comparable to antidepressant medication and other active, first-line psychotherapies, such as cogni­tive-behavioral therapy (CBT).^11,12

Although this review, as well as the liter­ature, focuses largely on adult outpatients with depression, evidence of IPT’s general efficacy exists for adolescents,¹³ chronically depressed patients,¹¹ and depressed inpa­tients.¹⁴ This article presents a case study to describe the structure of IPT when used to treat depressed adults. We also present evidence of IPT’s acute and long-term ef­ficacy in preventing depression recurrence and data to guide its use in practice.

CASE REPORT

‘Safe’ but depressed
Timothy, age 18, is a first-year college student who presents for outpatient psychotherapy to address recurrent depression. He reports general unhappiness, loss of interest in things, low energy, sleep problems, poor academic and work functioning, and low self-esteem. He experienced at least 3 similar depressive episodes while in high school.

The therapist’s diagnostic and interper­sonal assessment suggests that Timothy’s depression is interpersonally driven. Timothy longs for relational intimacy but fears he will fail or burden people with his needs. He has difficulty gauging appropriate lev­els of enmeshment with others and either becomes overdependent or stays at a dis­tance. This “safe” approach to relationships contributes to boredom, loneliness, and isolation. His recent transition to college away from home and the failure of a roman­tic relationship have compounded these experiences.

Interpersonal model of IPT
IPT conceptualizes depression as involving predisposing, precipitating, and perpetu­ating biopsychosocial factors, including:
   • underlying biological and social vul­nerability, such as insecure attach­ ment (ie, tenuous and often negative views of self and others)
   • current interpersonal life stressors
   • inadequate social supports.^15,16

For example, poor early attachment to caregivers can give rise to despair, isolation, and low mood. In turn, this can be exacerbated by poor social and commu­nication skills that promote further rejec­tion and withdrawal of social support and thus, intensified despair, isolation, and low mood. As in Timothy’s case, this vicious cycle underscores psychosocial stressors as a causal factor, maintaining factor, and result of depression. Specifically, IPT con­ceptualizes 4 main biopsychosocial problem domains:
   • grief and loss
   • interpersonal disputes
   • role transitions
   • interpersonal/communication deficits (often connected to isolation).

Working within 1 or 2 of the most salient problem domains, IPT centers on strategies for helping patients solve interpersonal problems based on the notion that modi­fied relationships, revised interpersonal expectations, improved communications, and increased social support will lead to symptom reduction.^15-17

Many techniques are utilized in IPT (Table 1) to help patients modify their interpersonal relationships as a mechanism for decreasing their distress. IPT is prob­lem-focused, aiming to improve patients’ relationships by drawing on their assets and helping to build skills around short­comings. Therefore, IPT focuses on observ­able interpersonal patterns, as opposed to latent personality dynamics.

CASE CONTINUED

Setting goals
When the clinical explains in the non-technical terms the data supporting IPT’s efficacy for depression, including with young adults, Timothy agrees to teeatment with acute IPT. The therapist behins with consciousness-raising techniques to help Timothy adopt the “sick role” by viewing depressing as an illness to be cured. Collaboratively, they establish treatment goals that fit the IPT formulation of depression— ie, revising current relationships and expectations of them, increasing social support, improving communication skills, and solving problems within 1 or 2 of the IPT prob­lem domains.

For Timothy, the most pressing psy­chosocial problems seem to be interper­sonal deficits and role transitions. He ap­pears to be insecurely attached to others, which is a risk factor for poor facilitation of, and boundaries around, good relation­ships. A transition to a new and intimidat­ing interpersonal context—living on a college campus—compounded his vulnerabilities and increased his depression.

Acute treatment. The acute phase of IPT is time-limited—often, 12 to 16 sessions with gradual tapering toward the end (akin to a continuation phase). The time limit’s pur­pose is to focus both patient and therapist on the specific goal of removing the acute “illness” of depression. The IPT clinician takes an interpersonal inventory to learn about the patient’s most important rela­tionships and hones in on the IPT domain foci. Working collaboratively, the thera­pist might help the patient mourn a loss, reconstruct a narrative with a deceased loved one, consider ways to increase social contact, develop assertiveness, label feel­ings and needs, resolve an impasse with a significant other, and so forth.

The IPT therapist is an advocate for the patient and adopts an active stance laced with empathy and warmth. However, the therapist is more than unconditionally ac­cepting as depression is viewed as a prob­lem to be actively resolved.

CASE CONTINUED

Creating new patterns
The therapist uses various IPT strategies to work collaboratively with Timothy. She at­tempts to develop a strong working alliance by building interpersonal safety and trust— which take time with an insecurely attached patient. She tries to provide a new model for how close relationships can develop, while also focusing on current relationships. She and Timothy address his romantic desire for a coworker and work on developing realistic ex­pectations and effective methods for convey­ing his interest.

When Timothy approaches his coworker, she does not reject him—as he expected— but wants to pursue friendship before pos­sibly dating. The therapist then works with Timothy’s emotional reaction and explores ways to effectively convey his emotions to this young woman. Drawing on communica­tion analysis and problem-solving strategies, Timothy is able to sustain this friendship—a shift from his typical retreat when relation­ships have not gone as hoped or expected.

Timothy develops confidence to take more risks in initiating social encounters and starts to confide in his roommates when he feels upset. After 3 months of treatment, his expanded social network and improved in­terpersonal skills result in decreased depres­sion. When Timothy suggests termination, he and the therapist agree to end acute IPT but—given his history of depression—to continue maintenance sessions.

Limited data exist on variables that relate to IPT’s acute success or conditions under which it works best. Although process re­search lags behind acute IPT outcome re­search, some findings can help guide the IPT practitioner. For example, variables shown to predict outcomes of acute IPT for depression include a positive therapeutic alliance, therapist warmth, and psycho­ psycho­therapist use of exploratory techniques (Table 2).

Similarly, IPT has been shown to be more effective in some patients than oth­ers, depending on various moderators of depression. For example:
   • For patients with high cognitive dys­function, IPT outperforms CBT.
   • For patients with higher need for medical reassurance, IPT outperforms selective serotonin reuptake inhibitor (SSRI) pharmacotherapy.
   • For patients with severe depression, CBT outperforms IPT.
   • For patients with low psychomotor activation, response is more rapid with an SSRI than with IPT (Table 3).¹⁸

Durability of acute IPT
One way to understand recurrence pre­vention is to examine the durability of a treatment’s acute effect in the absence of a specific maintenance plan. In theory, patients will continue to apply the skills learned in acute IPT to maintain gains and prevent recurrences, even after they stop seeing the psychotherapist.

Initial findings.  Some research speaks to IPT’s acute-phase durability. The inaugural clinical trial of IPT by Weissman et al¹⁹ included 4 months of acute treatment and a 1-year uncontrolled naturalistic follow-up assessment. At follow-up, depression and global clinical symptoms were the same, whether patients had been acutely treated with IPT alone, pharmacotherapy alone (amitriptyline), combined IPT and pharmacotherapy, or nonscheduled treat­ment with a psychiatrist.

Some patients continued to function well, whereas others did not fully main­tain acute treatment gains. Patients who received IPT acutely, either singly or with medication, showed better social function­ing at follow-up compared with patients who did not receive IPT. This long-term durability of social improvements was an obvious target of IPT.

Support from TDCRP. In the National Institute of Mental Health Treatment of Depression Collaborative Research Project (TDCRP),²⁰ patients in the acute phase of depression were assigned to 16 weeks of IPT, CBT, pharmacotherapy (imipramine) and clinical management (CM), or placebo plus CM. Among those who recovered by acute treatment’s end, MDD relapse rates at 18-month naturalistic follow-up were 33% for IPT, 36% for CBT, 50% for imipramine, and 33% for placebo. Between-group differ­ences were not statistically significant.

Because acute responders to different types of treatment might have different inherent relapse tendencies, these data do not support causal attributions about the enduring effects of acute-phase treatment. The relapse rates do suggest, however, that 16 weeks of acute treatment, irrespec­tive of kind, was insufficient for some pa­tients to achieve full recovery and lasting remission. Consistent with the initial IPT trial,¹⁹ IPT (and CBT) outperformed medi cation and placebo in maintaining rela­tionship quality.²¹

Long-term benefits. A more recent trial by Zobel et al²² examined the durabil­ity of benefits from 5 weeks of acute IPT plus pharmacotherapy and pharmaco­therapy plus CM for inpatients with MDD. Although caution is required in interpret­ing naturalistic follow-up studies, patients in both groups showed decreased depres­sion from baseline to 5-year follow-up. Early symptom reduction was more rapid for patients in the IPT plus pharmacother­apy group, but no significant difference ex­isted at 5 years. More IPT patients than CM patients showed sustained remission (28% vs 11%, respectively). These rates demon­strate a need for longer-term potency of acute treatments and more targeted main­tenance treatments.

IPT-M for preventing recurrence
A second way to understand recurrence prevention is to examine the efficacy of a treatment’s maintenance protocol add­ed to an acute treatment phase. IPT has been adapted as a maintenance treatment (IPT-M), with emphasis on keeping pa­tients well. With this revised focus, IPT-M differs somewhat from acute IPT. Although treatment continues to center on interper­sonal functioning, IPT-M favors:
   • vigilance for possible triggers of new depressive episodes
   • longer-term contact with a therapist
   • reinforcing skills learned
   • addressing an expanded number of interpersonal problem areas (given that such problems can be addressed more ef­ficiently relative to acute treatment).

Efficacy of IPT-M. In the initial trial, Frank et al²³ compared the efficacy of IPT-M with that of pharmacotherapy (imipramine) in preventing depressive relapse among pa­tients with recurrent depression who had responded to ≥16 sessions of acute IPT and imipramine and remained well during a 17- week continuation phase. For maintenance, patients were assigned to IPT-M alone, imipramine alone, placebo alone, IPT-M plus imipramine, or IPT-M plus placebo. Maintenance imipramine was continued at the acute dosage (target 200 mg/d; up to 400 mg/d was allowed). Maintenance IPT was monthly sessions. Patients remained in the trial for 3 years or until depression recurred.

On its own, IPT-M showed some efficacy in preventing recurrence, as the mean time to recurrence was 82 weeks for IPT-M alone and 74 weeks for IPT-M plus placebo. The prophylactic effect of imipramine was stron­ger, however. The mean time to recurrence for imipramine with IPT was 131 weeks, and the mean time to recurrence for imipra­mine without IPT was 124 weeks. Therefore, whereas monthly IPT-M can certainly help prolong wellness and delay recurrence, IPT maintenance treatment with acute doses of imipramine might be even more effective— if the patient is willing to take medication. These findings must be considered with caution because of the inherent inequity be­tween imipramine and IPT-M in regard to maintenance dosage strength.

Frequency of treatment. In another trial, Frank et al²⁴ examined whether the fre­quency of maintenance IPT sessions played a role in its prophylactic effect. Adult wom­en who had achieved depression remission with acute IPT (alone or in combination with SSRI pharmacotherapy) were ran­domized to weekly, bi-weekly, or monthly IPT-M alone for 2 years or until recurrence. Depression recurred during IPT-M in:
   • 26% of patients who had received acute IPT alone
   • 50% of those who had received acute IPT plus an SSRI.

Frequency of IPT-M sessions did not af­fect time to recurrence. Thus, for women who can achieve remission with IPT alone, varied frequencies of IPT-M can be good prophylaxis. For women who need an SSRI to augment acute IPT, IPT-M alone at varied dosages is less effective in pre­venting depression recurrence. Therefore, acute treatment response patterns can in­form maintenance plans, with the most prudent maintenance strategy being to maintain the acute treatment strategy over a longer period.

IPT-M for late-life depression. A trial by Reynolds et al25 examined the efficacy of maintenance nortriptyline and IPT-M in preventing depression recurrence in pa­tients age ≥59 who initially recovered after combined acute and continuation IPT plus nortriptyline. The 4 conditions (with their recurrence rates) were:
   • monthly IPT-M with nortriptyline (20%)
   • monthly IPT-M with placebo (64%)
   • nortriptyline plus medication visits (43%)
   • placebo plus medication visits (90%).

Clearly, the combined active treat­ments outperformed placebo and anti­depressant alone in terms of delaying or preventing recurrence, which suggests an optimal maintenance strategy with this population.

IPT-M for later life. Another trial by the same group²⁶ enrolled patients age ≥70 with MDD that responded to acute IPT plus paroxetine. The maintenance treat­ments to which they were randomly as­signed (and recurrence rates within 2 years) were:
   • paroxetine plus IPT-M (35%)
   • placebo plus IPT-M (68%)
   • paroxetine plus clinical management (37%)
   • placebo plus clinical management (58%).

Recurrence rates were the same for pa­tients receiving medication plus IPT-M and medication plus clinical management, and depression was 2.4 times more likely to recur in patients receiving placebo vs active medication. Therefore, for later life depression, the optimal maintenance strat­egy was the SSRI.

Secondary analyses of data from these seminal trials of IPT-M point to other predictors of how and for whom mainte­nance IPT may work (Table 4). For example:
   • Greater variability of depression symptoms during all forms of mainte­nance treatment is related to a greater risk of recurrence.
   • Persistent insomnia is related to greater risk of recurrent depression.
   • High interpersonal focus in IPT-M sessions is related to longer time to recurrence.

Bottom Line
Interpersonal psychotherapy (IPT) is efficacious for acute depression and for preventing recurrences. Patients treated successfully with acute IPT alone benefit from varied doses of maintenance IPT. Combining IPT-M with antidepressant medication can be more potent than IPT-M alone. For late-life depression, medication appears to be most effective for maintenance treatment.

Related Resources

Media
• Video demonstration, role-play transcripts, lesson plans, and quizzes. In: Appendices in and DVD companion to Ravitz P, Watson P, Grigoriadas S. Interpersonal psychother­apy for depression. New York, NY: Norton; 2013.
• Video demonstration of IPT sessions. In: DVD companion to Dewan, M, Steenbarger, B, Greenberg, R, eds. The art and science of brief psychotherapies: An illustrated guide. 2nd ed. Arlington, VA: American Psychiatric Publishing; 2012.

Text
• Stuart S, Robertson M. Interpersonal psychotherapy: a cli­nician’s guide. London, United Kingdom: Taylor & Francis; 2012.
• Weissman MM, Markowitz JC, Klerman GL. Comprehensive guide to interpersonal psychotherapy. New York, NY: Basic Books; 2000.
• Weissman M, Markowitz J, Klerman GL. Clinician’s quick guide to interpersonal psychotherapy. New York, NY: Oxford University Press; 2007.

Websites
• Interpersonal Psychotherapy Institute. http://iptinstitute.com.
• International Society for Interpersonal Psychotherapy. http://interpersonalpsychotherapy.org.

Drug Brand Names
Amitriptyline • Elavil       Nortriptyline • Pamelor
Imipramine • Tofranil     Paroxetine • Paxil

Acknowledgments
The authors are grateful to Samantha L. Bernecker, MS, and Nicholas R. Morrison for their assistance with the research review.

Disclosures
The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.

Major depressive disorder (MDD) frequently is recur­rent, with new episodes causing substantial social and economic impairment¹ and increasing the like­lihood of future episodes.² For this reason, contemporary psychiatric practitioners think of depression treatment as long-term and plan thoughtfully for maintenance therapy.

Recognizing the importance of engaging depressed indi­viduals beyond the initial response,³ American Psychiatric Association practice guidelines conceptualize depression treatment as 3 phases:
   • acute treatment, with the aim of remission (symptom removal)
   • continuation treatment, with the aim of preventing re­lapse (symptom return)
   • maintenance treatment, with the aim of preventing re­currence (new episodes).⁴
Interpersonal psychotherapy (IPT) is an evidence-based psychosocial treatment that adheres to this model.⁵ As a time-limited, manual-driven^6,7 approach, IPT focuses on interpersonal distresses as precipitating and perpetuating factors of depression.⁸

Acute IPT’s efficacy is well-established across >200 empirical studies—making it an evidence-based, first-line treatment for adult depression.^4,9,10 Meta-analyses show that acute IPT is superior to placebo and no-treatment con­trols, and largely comparable to antidepressant medication and other active, first-line psychotherapies, such as cogni­tive-behavioral therapy (CBT).^11,12

Although this review, as well as the liter­ature, focuses largely on adult outpatients with depression, evidence of IPT’s general efficacy exists for adolescents,¹³ chronically depressed patients,¹¹ and depressed inpa­tients.¹⁴ This article presents a case study to describe the structure of IPT when used to treat depressed adults. We also present evidence of IPT’s acute and long-term ef­ficacy in preventing depression recurrence and data to guide its use in practice.

CASE REPORT

‘Safe’ but depressed
Timothy, age 18, is a first-year college student who presents for outpatient psychotherapy to address recurrent depression. He reports general unhappiness, loss of interest in things, low energy, sleep problems, poor academic and work functioning, and low self-esteem. He experienced at least 3 similar depressive episodes while in high school.

The therapist’s diagnostic and interper­sonal assessment suggests that Timothy’s depression is interpersonally driven. Timothy longs for relational intimacy but fears he will fail or burden people with his needs. He has difficulty gauging appropriate lev­els of enmeshment with others and either becomes overdependent or stays at a dis­tance. This “safe” approach to relationships contributes to boredom, loneliness, and isolation. His recent transition to college away from home and the failure of a roman­tic relationship have compounded these experiences.

Interpersonal model of IPT
IPT conceptualizes depression as involving predisposing, precipitating, and perpetu­ating biopsychosocial factors, including:
   • underlying biological and social vul­nerability, such as insecure attach­ ment (ie, tenuous and often negative views of self and others)
   • current interpersonal life stressors
   • inadequate social supports.^15,16

For example, poor early attachment to caregivers can give rise to despair, isolation, and low mood. In turn, this can be exacerbated by poor social and commu­nication skills that promote further rejec­tion and withdrawal of social support and thus, intensified despair, isolation, and low mood. As in Timothy’s case, this vicious cycle underscores psychosocial stressors as a causal factor, maintaining factor, and result of depression. Specifically, IPT con­ceptualizes 4 main biopsychosocial problem domains:
   • grief and loss
   • interpersonal disputes
   • role transitions
   • interpersonal/communication deficits (often connected to isolation).

Working within 1 or 2 of the most salient problem domains, IPT centers on strategies for helping patients solve interpersonal problems based on the notion that modi­fied relationships, revised interpersonal expectations, improved communications, and increased social support will lead to symptom reduction.^15-17

Many techniques are utilized in IPT (Table 1) to help patients modify their interpersonal relationships as a mechanism for decreasing their distress. IPT is prob­lem-focused, aiming to improve patients’ relationships by drawing on their assets and helping to build skills around short­comings. Therefore, IPT focuses on observ­able interpersonal patterns, as opposed to latent personality dynamics.

CASE CONTINUED

Setting goals
When the clinical explains in the non-technical terms the data supporting IPT’s efficacy for depression, including with young adults, Timothy agrees to teeatment with acute IPT. The therapist behins with consciousness-raising techniques to help Timothy adopt the “sick role” by viewing depressing as an illness to be cured. Collaboratively, they establish treatment goals that fit the IPT formulation of depression— ie, revising current relationships and expectations of them, increasing social support, improving communication skills, and solving problems within 1 or 2 of the IPT prob­lem domains.

For Timothy, the most pressing psy­chosocial problems seem to be interper­sonal deficits and role transitions. He ap­pears to be insecurely attached to others, which is a risk factor for poor facilitation of, and boundaries around, good relation­ships. A transition to a new and intimidat­ing interpersonal context—living on a college campus—compounded his vulnerabilities and increased his depression.

Acute treatment. The acute phase of IPT is time-limited—often, 12 to 16 sessions with gradual tapering toward the end (akin to a continuation phase). The time limit’s pur­pose is to focus both patient and therapist on the specific goal of removing the acute “illness” of depression. The IPT clinician takes an interpersonal inventory to learn about the patient’s most important rela­tionships and hones in on the IPT domain foci. Working collaboratively, the thera­pist might help the patient mourn a loss, reconstruct a narrative with a deceased loved one, consider ways to increase social contact, develop assertiveness, label feel­ings and needs, resolve an impasse with a significant other, and so forth.

The IPT therapist is an advocate for the patient and adopts an active stance laced with empathy and warmth. However, the therapist is more than unconditionally ac­cepting as depression is viewed as a prob­lem to be actively resolved.

CASE CONTINUED

Creating new patterns
The therapist uses various IPT strategies to work collaboratively with Timothy. She at­tempts to develop a strong working alliance by building interpersonal safety and trust— which take time with an insecurely attached patient. She tries to provide a new model for how close relationships can develop, while also focusing on current relationships. She and Timothy address his romantic desire for a coworker and work on developing realistic ex­pectations and effective methods for convey­ing his interest.

When Timothy approaches his coworker, she does not reject him—as he expected— but wants to pursue friendship before pos­sibly dating. The therapist then works with Timothy’s emotional reaction and explores ways to effectively convey his emotions to this young woman. Drawing on communica­tion analysis and problem-solving strategies, Timothy is able to sustain this friendship—a shift from his typical retreat when relation­ships have not gone as hoped or expected.

Timothy develops confidence to take more risks in initiating social encounters and starts to confide in his roommates when he feels upset. After 3 months of treatment, his expanded social network and improved in­terpersonal skills result in decreased depres­sion. When Timothy suggests termination, he and the therapist agree to end acute IPT but—given his history of depression—to continue maintenance sessions.

Limited data exist on variables that relate to IPT’s acute success or conditions under which it works best. Although process re­search lags behind acute IPT outcome re­search, some findings can help guide the IPT practitioner. For example, variables shown to predict outcomes of acute IPT for depression include a positive therapeutic alliance, therapist warmth, and psycho­ psycho­therapist use of exploratory techniques (Table 2).

Similarly, IPT has been shown to be more effective in some patients than oth­ers, depending on various moderators of depression. For example:
   • For patients with high cognitive dys­function, IPT outperforms CBT.
   • For patients with higher need for medical reassurance, IPT outperforms selective serotonin reuptake inhibitor (SSRI) pharmacotherapy.
   • For patients with severe depression, CBT outperforms IPT.
   • For patients with low psychomotor activation, response is more rapid with an SSRI than with IPT (Table 3).¹⁸

Durability of acute IPT
One way to understand recurrence pre­vention is to examine the durability of a treatment’s acute effect in the absence of a specific maintenance plan. In theory, patients will continue to apply the skills learned in acute IPT to maintain gains and prevent recurrences, even after they stop seeing the psychotherapist.

Initial findings.  Some research speaks to IPT’s acute-phase durability. The inaugural clinical trial of IPT by Weissman et al¹⁹ included 4 months of acute treatment and a 1-year uncontrolled naturalistic follow-up assessment. At follow-up, depression and global clinical symptoms were the same, whether patients had been acutely treated with IPT alone, pharmacotherapy alone (amitriptyline), combined IPT and pharmacotherapy, or nonscheduled treat­ment with a psychiatrist.

Some patients continued to function well, whereas others did not fully main­tain acute treatment gains. Patients who received IPT acutely, either singly or with medication, showed better social function­ing at follow-up compared with patients who did not receive IPT. This long-term durability of social improvements was an obvious target of IPT.

Support from TDCRP. In the National Institute of Mental Health Treatment of Depression Collaborative Research Project (TDCRP),²⁰ patients in the acute phase of depression were assigned to 16 weeks of IPT, CBT, pharmacotherapy (imipramine) and clinical management (CM), or placebo plus CM. Among those who recovered by acute treatment’s end, MDD relapse rates at 18-month naturalistic follow-up were 33% for IPT, 36% for CBT, 50% for imipramine, and 33% for placebo. Between-group differ­ences were not statistically significant.

Because acute responders to different types of treatment might have different inherent relapse tendencies, these data do not support causal attributions about the enduring effects of acute-phase treatment. The relapse rates do suggest, however, that 16 weeks of acute treatment, irrespec­tive of kind, was insufficient for some pa­tients to achieve full recovery and lasting remission. Consistent with the initial IPT trial,¹⁹ IPT (and CBT) outperformed medi cation and placebo in maintaining rela­tionship quality.²¹

Long-term benefits. A more recent trial by Zobel et al²² examined the durabil­ity of benefits from 5 weeks of acute IPT plus pharmacotherapy and pharmaco­therapy plus CM for inpatients with MDD. Although caution is required in interpret­ing naturalistic follow-up studies, patients in both groups showed decreased depres­sion from baseline to 5-year follow-up. Early symptom reduction was more rapid for patients in the IPT plus pharmacother­apy group, but no significant difference ex­isted at 5 years. More IPT patients than CM patients showed sustained remission (28% vs 11%, respectively). These rates demon­strate a need for longer-term potency of acute treatments and more targeted main­tenance treatments.

IPT-M for preventing recurrence
A second way to understand recurrence prevention is to examine the efficacy of a treatment’s maintenance protocol add­ed to an acute treatment phase. IPT has been adapted as a maintenance treatment (IPT-M), with emphasis on keeping pa­tients well. With this revised focus, IPT-M differs somewhat from acute IPT. Although treatment continues to center on interper­sonal functioning, IPT-M favors:
   • vigilance for possible triggers of new depressive episodes
   • longer-term contact with a therapist
   • reinforcing skills learned
   • addressing an expanded number of interpersonal problem areas (given that such problems can be addressed more ef­ficiently relative to acute treatment).

Efficacy of IPT-M. In the initial trial, Frank et al²³ compared the efficacy of IPT-M with that of pharmacotherapy (imipramine) in preventing depressive relapse among pa­tients with recurrent depression who had responded to ≥16 sessions of acute IPT and imipramine and remained well during a 17- week continuation phase. For maintenance, patients were assigned to IPT-M alone, imipramine alone, placebo alone, IPT-M plus imipramine, or IPT-M plus placebo. Maintenance imipramine was continued at the acute dosage (target 200 mg/d; up to 400 mg/d was allowed). Maintenance IPT was monthly sessions. Patients remained in the trial for 3 years or until depression recurred.

On its own, IPT-M showed some efficacy in preventing recurrence, as the mean time to recurrence was 82 weeks for IPT-M alone and 74 weeks for IPT-M plus placebo. The prophylactic effect of imipramine was stron­ger, however. The mean time to recurrence for imipramine with IPT was 131 weeks, and the mean time to recurrence for imipra­mine without IPT was 124 weeks. Therefore, whereas monthly IPT-M can certainly help prolong wellness and delay recurrence, IPT maintenance treatment with acute doses of imipramine might be even more effective— if the patient is willing to take medication. These findings must be considered with caution because of the inherent inequity be­tween imipramine and IPT-M in regard to maintenance dosage strength.

Frequency of treatment. In another trial, Frank et al²⁴ examined whether the fre­quency of maintenance IPT sessions played a role in its prophylactic effect. Adult wom­en who had achieved depression remission with acute IPT (alone or in combination with SSRI pharmacotherapy) were ran­domized to weekly, bi-weekly, or monthly IPT-M alone for 2 years or until recurrence. Depression recurred during IPT-M in:
   • 26% of patients who had received acute IPT alone
   • 50% of those who had received acute IPT plus an SSRI.

Frequency of IPT-M sessions did not af­fect time to recurrence. Thus, for women who can achieve remission with IPT alone, varied frequencies of IPT-M can be good prophylaxis. For women who need an SSRI to augment acute IPT, IPT-M alone at varied dosages is less effective in pre­venting depression recurrence. Therefore, acute treatment response patterns can in­form maintenance plans, with the most prudent maintenance strategy being to maintain the acute treatment strategy over a longer period.

IPT-M for late-life depression. A trial by Reynolds et al25 examined the efficacy of maintenance nortriptyline and IPT-M in preventing depression recurrence in pa­tients age ≥59 who initially recovered after combined acute and continuation IPT plus nortriptyline. The 4 conditions (with their recurrence rates) were:
   • monthly IPT-M with nortriptyline (20%)
   • monthly IPT-M with placebo (64%)
   • nortriptyline plus medication visits (43%)
   • placebo plus medication visits (90%).

Clearly, the combined active treat­ments outperformed placebo and anti­depressant alone in terms of delaying or preventing recurrence, which suggests an optimal maintenance strategy with this population.

IPT-M for later life. Another trial by the same group²⁶ enrolled patients age ≥70 with MDD that responded to acute IPT plus paroxetine. The maintenance treat­ments to which they were randomly as­signed (and recurrence rates within 2 years) were:
   • paroxetine plus IPT-M (35%)
   • placebo plus IPT-M (68%)
   • paroxetine plus clinical management (37%)
   • placebo plus clinical management (58%).

Recurrence rates were the same for pa­tients receiving medication plus IPT-M and medication plus clinical management, and depression was 2.4 times more likely to recur in patients receiving placebo vs active medication. Therefore, for later life depression, the optimal maintenance strat­egy was the SSRI.

Secondary analyses of data from these seminal trials of IPT-M point to other predictors of how and for whom mainte­nance IPT may work (Table 4). For example:
   • Greater variability of depression symptoms during all forms of mainte­nance treatment is related to a greater risk of recurrence.
   • Persistent insomnia is related to greater risk of recurrent depression.
   • High interpersonal focus in IPT-M sessions is related to longer time to recurrence.

Bottom Line
Interpersonal psychotherapy (IPT) is efficacious for acute depression and for preventing recurrences. Patients treated successfully with acute IPT alone benefit from varied doses of maintenance IPT. Combining IPT-M with antidepressant medication can be more potent than IPT-M alone. For late-life depression, medication appears to be most effective for maintenance treatment.

Related Resources

Media
• Video demonstration, role-play transcripts, lesson plans, and quizzes. In: Appendices in and DVD companion to Ravitz P, Watson P, Grigoriadas S. Interpersonal psychother­apy for depression. New York, NY: Norton; 2013.
• Video demonstration of IPT sessions. In: DVD companion to Dewan, M, Steenbarger, B, Greenberg, R, eds. The art and science of brief psychotherapies: An illustrated guide. 2nd ed. Arlington, VA: American Psychiatric Publishing; 2012.

Text
• Stuart S, Robertson M. Interpersonal psychotherapy: a cli­nician’s guide. London, United Kingdom: Taylor & Francis; 2012.
• Weissman MM, Markowitz JC, Klerman GL. Comprehensive guide to interpersonal psychotherapy. New York, NY: Basic Books; 2000.
• Weissman M, Markowitz J, Klerman GL. Clinician’s quick guide to interpersonal psychotherapy. New York, NY: Oxford University Press; 2007.

Websites
• Interpersonal Psychotherapy Institute. http://iptinstitute.com.
• International Society for Interpersonal Psychotherapy. http://interpersonalpsychotherapy.org.

Drug Brand Names
Amitriptyline • Elavil       Nortriptyline • Pamelor
Imipramine • Tofranil     Paroxetine • Paxil

Acknowledgments
The authors are grateful to Samantha L. Bernecker, MS, and Nicholas R. Morrison for their assistance with the research review.

Disclosures
The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.

Major depressive disorder (MDD) frequently is recur­rent, with new episodes causing substantial social and economic impairment¹ and increasing the like­lihood of future episodes.² For this reason, contemporary psychiatric practitioners think of depression treatment as long-term and plan thoughtfully for maintenance therapy.

Recognizing the importance of engaging depressed indi­viduals beyond the initial response,³ American Psychiatric Association practice guidelines conceptualize depression treatment as 3 phases:
   • acute treatment, with the aim of remission (symptom removal)
   • continuation treatment, with the aim of preventing re­lapse (symptom return)
   • maintenance treatment, with the aim of preventing re­currence (new episodes).⁴
Interpersonal psychotherapy (IPT) is an evidence-based psychosocial treatment that adheres to this model.⁵ As a time-limited, manual-driven^6,7 approach, IPT focuses on interpersonal distresses as precipitating and perpetuating factors of depression.⁸

Acute IPT’s efficacy is well-established across >200 empirical studies—making it an evidence-based, first-line treatment for adult depression.^4,9,10 Meta-analyses show that acute IPT is superior to placebo and no-treatment con­trols, and largely comparable to antidepressant medication and other active, first-line psychotherapies, such as cogni­tive-behavioral therapy (CBT).^11,12

Although this review, as well as the liter­ature, focuses largely on adult outpatients with depression, evidence of IPT’s general efficacy exists for adolescents,¹³ chronically depressed patients,¹¹ and depressed inpa­tients.¹⁴ This article presents a case study to describe the structure of IPT when used to treat depressed adults. We also present evidence of IPT’s acute and long-term ef­ficacy in preventing depression recurrence and data to guide its use in practice.

CASE REPORT

‘Safe’ but depressed
Timothy, age 18, is a first-year college student who presents for outpatient psychotherapy to address recurrent depression. He reports general unhappiness, loss of interest in things, low energy, sleep problems, poor academic and work functioning, and low self-esteem. He experienced at least 3 similar depressive episodes while in high school.

The therapist’s diagnostic and interper­sonal assessment suggests that Timothy’s depression is interpersonally driven. Timothy longs for relational intimacy but fears he will fail or burden people with his needs. He has difficulty gauging appropriate lev­els of enmeshment with others and either becomes overdependent or stays at a dis­tance. This “safe” approach to relationships contributes to boredom, loneliness, and isolation. His recent transition to college away from home and the failure of a roman­tic relationship have compounded these experiences.

Interpersonal model of IPT
IPT conceptualizes depression as involving predisposing, precipitating, and perpetu­ating biopsychosocial factors, including:
   • underlying biological and social vul­nerability, such as insecure attach­ ment (ie, tenuous and often negative views of self and others)
   • current interpersonal life stressors
   • inadequate social supports.^15,16

For example, poor early attachment to caregivers can give rise to despair, isolation, and low mood. In turn, this can be exacerbated by poor social and commu­nication skills that promote further rejec­tion and withdrawal of social support and thus, intensified despair, isolation, and low mood. As in Timothy’s case, this vicious cycle underscores psychosocial stressors as a causal factor, maintaining factor, and result of depression. Specifically, IPT con­ceptualizes 4 main biopsychosocial problem domains:
   • grief and loss
   • interpersonal disputes
   • role transitions
   • interpersonal/communication deficits (often connected to isolation).

Working within 1 or 2 of the most salient problem domains, IPT centers on strategies for helping patients solve interpersonal problems based on the notion that modi­fied relationships, revised interpersonal expectations, improved communications, and increased social support will lead to symptom reduction.^15-17

Many techniques are utilized in IPT (Table 1) to help patients modify their interpersonal relationships as a mechanism for decreasing their distress. IPT is prob­lem-focused, aiming to improve patients’ relationships by drawing on their assets and helping to build skills around short­comings. Therefore, IPT focuses on observ­able interpersonal patterns, as opposed to latent personality dynamics.

CASE CONTINUED

Setting goals
When the clinical explains in the non-technical terms the data supporting IPT’s efficacy for depression, including with young adults, Timothy agrees to teeatment with acute IPT. The therapist behins with consciousness-raising techniques to help Timothy adopt the “sick role” by viewing depressing as an illness to be cured. Collaboratively, they establish treatment goals that fit the IPT formulation of depression— ie, revising current relationships and expectations of them, increasing social support, improving communication skills, and solving problems within 1 or 2 of the IPT prob­lem domains.

For Timothy, the most pressing psy­chosocial problems seem to be interper­sonal deficits and role transitions. He ap­pears to be insecurely attached to others, which is a risk factor for poor facilitation of, and boundaries around, good relation­ships. A transition to a new and intimidat­ing interpersonal context—living on a college campus—compounded his vulnerabilities and increased his depression.

Acute treatment. The acute phase of IPT is time-limited—often, 12 to 16 sessions with gradual tapering toward the end (akin to a continuation phase). The time limit’s pur­pose is to focus both patient and therapist on the specific goal of removing the acute “illness” of depression. The IPT clinician takes an interpersonal inventory to learn about the patient’s most important rela­tionships and hones in on the IPT domain foci. Working collaboratively, the thera­pist might help the patient mourn a loss, reconstruct a narrative with a deceased loved one, consider ways to increase social contact, develop assertiveness, label feel­ings and needs, resolve an impasse with a significant other, and so forth.

The IPT therapist is an advocate for the patient and adopts an active stance laced with empathy and warmth. However, the therapist is more than unconditionally ac­cepting as depression is viewed as a prob­lem to be actively resolved.

CASE CONTINUED

Creating new patterns
The therapist uses various IPT strategies to work collaboratively with Timothy. She at­tempts to develop a strong working alliance by building interpersonal safety and trust— which take time with an insecurely attached patient. She tries to provide a new model for how close relationships can develop, while also focusing on current relationships. She and Timothy address his romantic desire for a coworker and work on developing realistic ex­pectations and effective methods for convey­ing his interest.

When Timothy approaches his coworker, she does not reject him—as he expected— but wants to pursue friendship before pos­sibly dating. The therapist then works with Timothy’s emotional reaction and explores ways to effectively convey his emotions to this young woman. Drawing on communica­tion analysis and problem-solving strategies, Timothy is able to sustain this friendship—a shift from his typical retreat when relation­ships have not gone as hoped or expected.

Timothy develops confidence to take more risks in initiating social encounters and starts to confide in his roommates when he feels upset. After 3 months of treatment, his expanded social network and improved in­terpersonal skills result in decreased depres­sion. When Timothy suggests termination, he and the therapist agree to end acute IPT but—given his history of depression—to continue maintenance sessions.

Limited data exist on variables that relate to IPT’s acute success or conditions under which it works best. Although process re­search lags behind acute IPT outcome re­search, some findings can help guide the IPT practitioner. For example, variables shown to predict outcomes of acute IPT for depression include a positive therapeutic alliance, therapist warmth, and psycho­ psycho­therapist use of exploratory techniques (Table 2).

Similarly, IPT has been shown to be more effective in some patients than oth­ers, depending on various moderators of depression. For example:
   • For patients with high cognitive dys­function, IPT outperforms CBT.
   • For patients with higher need for medical reassurance, IPT outperforms selective serotonin reuptake inhibitor (SSRI) pharmacotherapy.
   • For patients with severe depression, CBT outperforms IPT.
   • For patients with low psychomotor activation, response is more rapid with an SSRI than with IPT (Table 3).¹⁸

Durability of acute IPT
One way to understand recurrence pre­vention is to examine the durability of a treatment’s acute effect in the absence of a specific maintenance plan. In theory, patients will continue to apply the skills learned in acute IPT to maintain gains and prevent recurrences, even after they stop seeing the psychotherapist.

Initial findings.  Some research speaks to IPT’s acute-phase durability. The inaugural clinical trial of IPT by Weissman et al¹⁹ included 4 months of acute treatment and a 1-year uncontrolled naturalistic follow-up assessment. At follow-up, depression and global clinical symptoms were the same, whether patients had been acutely treated with IPT alone, pharmacotherapy alone (amitriptyline), combined IPT and pharmacotherapy, or nonscheduled treat­ment with a psychiatrist.

Some patients continued to function well, whereas others did not fully main­tain acute treatment gains. Patients who received IPT acutely, either singly or with medication, showed better social function­ing at follow-up compared with patients who did not receive IPT. This long-term durability of social improvements was an obvious target of IPT.

Support from TDCRP. In the National Institute of Mental Health Treatment of Depression Collaborative Research Project (TDCRP),²⁰ patients in the acute phase of depression were assigned to 16 weeks of IPT, CBT, pharmacotherapy (imipramine) and clinical management (CM), or placebo plus CM. Among those who recovered by acute treatment’s end, MDD relapse rates at 18-month naturalistic follow-up were 33% for IPT, 36% for CBT, 50% for imipramine, and 33% for placebo. Between-group differ­ences were not statistically significant.

Because acute responders to different types of treatment might have different inherent relapse tendencies, these data do not support causal attributions about the enduring effects of acute-phase treatment. The relapse rates do suggest, however, that 16 weeks of acute treatment, irrespec­tive of kind, was insufficient for some pa­tients to achieve full recovery and lasting remission. Consistent with the initial IPT trial,¹⁹ IPT (and CBT) outperformed medi cation and placebo in maintaining rela­tionship quality.²¹

Long-term benefits. A more recent trial by Zobel et al²² examined the durabil­ity of benefits from 5 weeks of acute IPT plus pharmacotherapy and pharmaco­therapy plus CM for inpatients with MDD. Although caution is required in interpret­ing naturalistic follow-up studies, patients in both groups showed decreased depres­sion from baseline to 5-year follow-up. Early symptom reduction was more rapid for patients in the IPT plus pharmacother­apy group, but no significant difference ex­isted at 5 years. More IPT patients than CM patients showed sustained remission (28% vs 11%, respectively). These rates demon­strate a need for longer-term potency of acute treatments and more targeted main­tenance treatments.

IPT-M for preventing recurrence
A second way to understand recurrence prevention is to examine the efficacy of a treatment’s maintenance protocol add­ed to an acute treatment phase. IPT has been adapted as a maintenance treatment (IPT-M), with emphasis on keeping pa­tients well. With this revised focus, IPT-M differs somewhat from acute IPT. Although treatment continues to center on interper­sonal functioning, IPT-M favors:
   • vigilance for possible triggers of new depressive episodes
   • longer-term contact with a therapist
   • reinforcing skills learned
   • addressing an expanded number of interpersonal problem areas (given that such problems can be addressed more ef­ficiently relative to acute treatment).

Efficacy of IPT-M. In the initial trial, Frank et al²³ compared the efficacy of IPT-M with that of pharmacotherapy (imipramine) in preventing depressive relapse among pa­tients with recurrent depression who had responded to ≥16 sessions of acute IPT and imipramine and remained well during a 17- week continuation phase. For maintenance, patients were assigned to IPT-M alone, imipramine alone, placebo alone, IPT-M plus imipramine, or IPT-M plus placebo. Maintenance imipramine was continued at the acute dosage (target 200 mg/d; up to 400 mg/d was allowed). Maintenance IPT was monthly sessions. Patients remained in the trial for 3 years or until depression recurred.

On its own, IPT-M showed some efficacy in preventing recurrence, as the mean time to recurrence was 82 weeks for IPT-M alone and 74 weeks for IPT-M plus placebo. The prophylactic effect of imipramine was stron­ger, however. The mean time to recurrence for imipramine with IPT was 131 weeks, and the mean time to recurrence for imipra­mine without IPT was 124 weeks. Therefore, whereas monthly IPT-M can certainly help prolong wellness and delay recurrence, IPT maintenance treatment with acute doses of imipramine might be even more effective— if the patient is willing to take medication. These findings must be considered with caution because of the inherent inequity be­tween imipramine and IPT-M in regard to maintenance dosage strength.

Frequency of treatment. In another trial, Frank et al²⁴ examined whether the fre­quency of maintenance IPT sessions played a role in its prophylactic effect. Adult wom­en who had achieved depression remission with acute IPT (alone or in combination with SSRI pharmacotherapy) were ran­domized to weekly, bi-weekly, or monthly IPT-M alone for 2 years or until recurrence. Depression recurred during IPT-M in:
   • 26% of patients who had received acute IPT alone
   • 50% of those who had received acute IPT plus an SSRI.

Frequency of IPT-M sessions did not af­fect time to recurrence. Thus, for women who can achieve remission with IPT alone, varied frequencies of IPT-M can be good prophylaxis. For women who need an SSRI to augment acute IPT, IPT-M alone at varied dosages is less effective in pre­venting depression recurrence. Therefore, acute treatment response patterns can in­form maintenance plans, with the most prudent maintenance strategy being to maintain the acute treatment strategy over a longer period.

IPT-M for late-life depression. A trial by Reynolds et al25 examined the efficacy of maintenance nortriptyline and IPT-M in preventing depression recurrence in pa­tients age ≥59 who initially recovered after combined acute and continuation IPT plus nortriptyline. The 4 conditions (with their recurrence rates) were:
   • monthly IPT-M with nortriptyline (20%)
   • monthly IPT-M with placebo (64%)
   • nortriptyline plus medication visits (43%)
   • placebo plus medication visits (90%).

Clearly, the combined active treat­ments outperformed placebo and anti­depressant alone in terms of delaying or preventing recurrence, which suggests an optimal maintenance strategy with this population.

IPT-M for later life. Another trial by the same group²⁶ enrolled patients age ≥70 with MDD that responded to acute IPT plus paroxetine. The maintenance treat­ments to which they were randomly as­signed (and recurrence rates within 2 years) were:
   • paroxetine plus IPT-M (35%)
   • placebo plus IPT-M (68%)
   • paroxetine plus clinical management (37%)
   • placebo plus clinical management (58%).

Recurrence rates were the same for pa­tients receiving medication plus IPT-M and medication plus clinical management, and depression was 2.4 times more likely to recur in patients receiving placebo vs active medication. Therefore, for later life depression, the optimal maintenance strat­egy was the SSRI.

Secondary analyses of data from these seminal trials of IPT-M point to other predictors of how and for whom mainte­nance IPT may work (Table 4). For example:
   • Greater variability of depression symptoms during all forms of mainte­nance treatment is related to a greater risk of recurrence.
   • Persistent insomnia is related to greater risk of recurrent depression.
   • High interpersonal focus in IPT-M sessions is related to longer time to recurrence.

Bottom Line
Interpersonal psychotherapy (IPT) is efficacious for acute depression and for preventing recurrences. Patients treated successfully with acute IPT alone benefit from varied doses of maintenance IPT. Combining IPT-M with antidepressant medication can be more potent than IPT-M alone. For late-life depression, medication appears to be most effective for maintenance treatment.

Related Resources

Media
• Video demonstration, role-play transcripts, lesson plans, and quizzes. In: Appendices in and DVD companion to Ravitz P, Watson P, Grigoriadas S. Interpersonal psychother­apy for depression. New York, NY: Norton; 2013.
• Video demonstration of IPT sessions. In: DVD companion to Dewan, M, Steenbarger, B, Greenberg, R, eds. The art and science of brief psychotherapies: An illustrated guide. 2nd ed. Arlington, VA: American Psychiatric Publishing; 2012.

Text
• Stuart S, Robertson M. Interpersonal psychotherapy: a cli­nician’s guide. London, United Kingdom: Taylor & Francis; 2012.
• Weissman MM, Markowitz JC, Klerman GL. Comprehensive guide to interpersonal psychotherapy. New York, NY: Basic Books; 2000.
• Weissman M, Markowitz J, Klerman GL. Clinician’s quick guide to interpersonal psychotherapy. New York, NY: Oxford University Press; 2007.

Websites
• Interpersonal Psychotherapy Institute. http://iptinstitute.com.
• International Society for Interpersonal Psychotherapy. http://interpersonalpsychotherapy.org.

Drug Brand Names
Amitriptyline • Elavil       Nortriptyline • Pamelor
Imipramine • Tofranil     Paroxetine • Paxil

Acknowledgments
The authors are grateful to Samantha L. Bernecker, MS, and Nicholas R. Morrison for their assistance with the research review.

Disclosures
The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.