METHOD

We performed secondary data analyses of an archived study27 to test this hypothesis. Method and study design have been described in detail elsewhere27 but will be briefly reviewed. The original protocol from which our sample was drawn was designed to explore the relative efficacy of 5 maintenance treatment strategies in preventing or delaying recurrences in a sample of patients with highly recurrent unipolar depression. 27, 28 To enter the Maintenance Therapies in Recurrent Depression protocol, subjects between ages 21 and 65 years were required to have a minimum 10-week remission between the index episode (3rd or greater episode) and the immediately prior episode, according to Research Diagnostic Criteria (RDC). 29 A minimum Hamilton Rating Scale for Depression (HAM-D) 62 score of 15 and a minimum score of 7 on the Raskin Severity of Depression Scale30 were also required for study participation. Eligible patients were then evaluated using the Schedule for Affective Disorders and Schizophrenia. 31 Those patients who met both RDC for a major depressive episode and the historical requirements for previous episodes and clear remissions were entered into the protocol. After complete description of the study to the subjects, written informed consent was obtained.

Prior to entering the maintenance phase of the study, all patients (N= 230) received acute treatment consisting of a combination of imipramine hydrochloride (150 to 300 mg) and IPT. 32 At baseline, in addition to the depression severity criteria described above, both self-reported somatic and pain symptoms were assessed with the Hopkins Symptom Checklist (SCL-90). 33 Each item of the SCL-90 is rated on a 5-point Likert scale, and is a response to the question,“How much were you bothered by...?” The time assessed is the past 7 days. The somatic domain of the SCL-90 was used to determine the somatic score. We created a pain domain from the SCL-90 by selecting the 4 questions that were pain specific. The items that make up both the somatic and pain scores are shown in Table 1. The domain score is an average of the items, with a higher score indicating greater symptomatology. Treatment sessions were scheduled weekly for 12 weeks, then biweekly for 8 weeks, and then monthly. Remission was defined as achieving both a HAM-D score of less than or equal to 7, and a Raskin score of less than or equal to 5, for 3 consecutive weeks. When these criteria were met, patients entered the continuation phase of the study.