To prevent depression recurrence, interpersonal psychotherapy is a first-line treatment with long-term benefits

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.