Interpersonal Therapy Promising as Maintenance Treatment

An outpatient, maintenance regimen of interpersonal psychotherapy (IPT)—without concomitant antidepressant medication—appears to be as beneficial for some women who suffer repeated episodes of depression as treatment with antidepressants alone or psychotherapy and antidepressants together, according to investigators in the departments of psychiatry and psychology at the University of Pittsburgh School of Medicine and the Western Psychiatric Institute and Clinic.

Indeed, the investigators said that their data suggest that even“ relatively infrequent contact, in the form of either booster sessions or monthly treatment sessions [of IPT], may be sufficient to protect the majority of individuals who are able to achieve remission with psychotherapy alone in the subsequent one to two years.”

The study, reported in the May American Journal of Psychiatry, enrolled 233 women aged 20 to 60 between 1992 and April 1999. Among the eligibility criteria were that the women had to be experiencing at least their second episode of unipolar depression and were willing to consider a nonpharmacologic approach leading up to and during maintenance treatment.

Once the subjects achieved remission with weekly IPT only—or if need be, with weekly IPT and antidepressant therapy—they randomly were placed into three groups in which they would receive booster doses of IPT either weekly, twice monthly, or monthly for two years.

“Remission” was defined as having minimal or no symptoms for three consecutive weeks as evidenced by a HAM-D score of 7 or less.

During the acute treatment phase, subjects who had not reached remission with four IPT sessions in four weeks had their IPT sessions increased to twice a week for four weeks. Further, the women who had not reached remission but who had agreed to the option of pharmacologic treatment also had twice a week IPT. Once remission of their symptoms was confirmed with a HAM-D score of 7 or less for three continuous weeks, these women entered into a“ continuation phase” of up to 17 weeks. Only at the end of this phase were they randomly assigned to the weekly, twice monthly, or monthly maintenance IPT sessions for two years or until symptoms recurred.

Recurrence was defined as meeting the DSM-IV criteria for major depression, as “confirmed by a senior psychiatrist who was not part of the investigative team.”

Of the women enrolled in the study, 131 ultimately achieved remission and entered the IPT-only maintenance phase. Ninetynine women achieved remission of their depression symptoms with IPT alone during the acute-treatment phase of the trial, which spanned 12 to 24 weeks. Of these, only 19 (26 percent of the 74 women who were able to complete two years of maintenance treatment) experienced a recurrence of depression.

“This rate is among the lowest observed to date in maintenance treatment studies involving patients with established histories of recurrence,” wrote Ellen Frank Ph.D, and colleagues.

What does this mean for women and their clinicians? “Some women with quite recurrent depression—about 50 percent—can achieve and maintain remission with a depression-specific psychotherapy alone,” Frank told Psychiatric News. “Particularly for women in the childbearing years, this should be considered as a first-line treatment, especially because among those who do not achieve remission with psychotherapy alone, the remission rate is very high once medication is added.”

Subjects who remained in the trial for the full two years were generally in total remission throughout that period. Of the 90 women requiring a sequential treatment of IPT and antidepressant therapy, only 32 (36 percent) sustained that remission through a “continuation” phase and ultimately qualified to enter the IPT-only maintenance phase. Of that group, 13 of the 26 who remained in maintenance suffered a recurrence of symptoms.

The study results “suggest that maintenance IPT, even at a frequency of only one visit per month, is a good method of prophylaxis for women who can achieve remission with IPT alone,” the researchers concluded.

In their review of the literature, the investigators noted there is now a solid body of evidence that shows long-term maintenance treatment of patients with unipolar depression with full-dose medications is the most effective way to sustain remission of symptoms. But for many patients, this is not the preferred treatment. The authors pointed to data suggesting that more women than men generally opt for nonpharmacologic intervention.

The authors explained that “because our goal was to study various `doses' of IPT alone as a maintenance treatment, and because our participants had entered the study with the hope of being treated and maintained recurrence-free without medication, we attempted discontinuation of the SSRI at the end of the [post-acute]continuation phase over a period of one to four weeks. The SSRI was discontinued only after a careful discussion [with the patient] of the potential risks of discontinuing medication and with careful monitoring of patients. These participants continued to receive IPT alone for four to six weeks to ensure that their remission was stable before they entered into the experimental phase.”

Those in the post-acute, continuation phase, who experienced an onset of symptoms reflecting criteria of a major depression were deemed to have“ relapsed.” They were withdrawn from the study and provided with appropriate treatment intervention.

The investigators acknowledged that the major limitation in the study's design was that it did not feature a “no-treatment” comparison group. They considered it risky and “unethical” to include such a study population.

They said that their results point to three conclusions: (1) when IPT alone is effective in bringing about a remission of symptoms, it is also effective as a maintenance treatment; (2) in the maintenance phase, IPT delivered at weekly or twice-monthly intervals is no more effective in maintaining remission than IPT delivered on a monthly basis; and (3) when IPT alone is not effective in the acute treatment phase, it is generally not effective in maintaining remission. Thus, for women who require combined treatment to achieve remission, IPT alone cannot be recommended as a maintenance treatment.

The study was supported by the National Institute of Mental Health.

“Randomized Trial of Weekly, Twice-Monthly, and Monthly Interpersonal Psychotherapy as Maintenance Treatment for Women With Recurrent Depression” is posted at<http://ajp.psychiatryonline.org/cgi/content/full/164/5/761>.▪

Am J Psychiatry 2007 164 761