Mean score comparisons revealed a significant change from baseline to post-treatment for both EPDS and Ham-D-21 scores (). However, there were no significant differences on the IIP or the DAS total scores. Means are reported with standard deviations throughout this section.
There was no difference on depression scores at the beginning of the treatment between those who completed treatment (n=11) and those who terminated early (n=6). However, these two groups differed on levels of marital satisfaction on the DAS, with the early termination group reporting less satisfaction with their marriages (mean=76.3±7.0) than those who stayed in treatment (110.1±14.5; t= 3.82, df=11, P<0.01).
Examination of individual Ham-D-21 score profiles revealed that 10 of 17 women (58%) demonstrated a full remission (posttreatment score <9). The criterion for full remission is defined as <8 points on the Ham-D 17-item scale.20
Because we used the 21-item scale in our study, we adapted the remission criteria, increasing the value by one point. Five of 17 women (29%) demonstrated a partial remission (score decrease >50%) at the end of treatment. Only 2 participants (11%) demonstrated no improvement.
There was no difference in baseline depression scores between fully remitted women and those who responded only partially or not at all; however, these groups differed on two IIP subscale scores at the time of the first assessment. Specifically, fully remitted women were initially less socially avoidant (mean=10.5±6.5) than women with partial or no remission (21.3±5.3; t=3.50, df=13, P<0.01), and fully remitted women were initially less vindictive (8.9±3.4) than those with partial or no remission (12.8±1.8; t=2.80, df=13, P<0.01). There were no demographic differences in age, parity, marital status, or occupational status between women who terminated early and those who completed the full course of treatment. A subset of the sample (n=13) was available for follow-up assessment at 6 months post-treatment. This subset consisted of 10 of the 11 women who completed the trial and 3 of the 6 who terminated early.
To examine whether treatment effects persisted, two separate multivariate analysis of variance tests were conducted, with the EPDS and Ham-D-21 treated as repeated measures. Participants' depression scores at the 6-month follow-up were significantly lower than at baseline (EPDS: F=24.30, df=1,12, P<0.001; Ham-D-21: F=33.59, df=1,12, P<0.001). Furthermore, participants' depression levels from post-treatment to 6-month follow-up were stable (on the EPDS, F<1), or continued to decrease (on the Ham-D-21, F=4.92, df=1,12, P<0.05).
There was no change in participants' IIP total scores or their DAS scores across the three time points. However, analysis of the IIP subdomains yielded significant differences on participants' nonassertive scale scores from baseline (mean=17.6±5.4) to post-treatment (15.7±6.4; t=2.59, df=13, P<0. 05).
Illustrative Case Example
During the first two individual sessions, the therapist helped each participant to identify one or two primary issues that she believed contributed to the onset of her depression. Interpersonal disputes, including interaction problems with the infant and/or marital conflict, were identified as a key problem area by the majority of the women (n=12). Difficulties with the process of role transition, such as coping with the loss of autonomy and the demands of caring for a dependent newborn, as well as feelings of isolation after taking leave from work, was the second most commonly identified concern (n=4). Two women identified their longstanding difficulties with interpersonal relationships as the key problem area contributing to their depression. One participant, who had previously miscarried, identified grief as the primary issue.
A particular advantage of the group approach to IPT individual therapy was that it allowed the participants to identify and address many shared concerns relating to their experiences of parenting and depression. The following vignette was selected to demonstrate how individuals' particular problem areas were addressed in the context of the group.