Does Reducing Social Disconnectedness Represent a Mechanism Whereby Depression Treatment Reduces Suicide Risk

Introduction: Social disconnectedness increases risk for mental illness in later life, including depression, as well as risk for suicide. The purpose of the current project is to examine the effectiveness of a psychotherapeutic intervention designed to impact social functioning—Interpersonal Psychotherapy (IPT)—in the treatment of suicidal ideation in later life, and to explore whether a mechanism of effectiveness is through decreased disconnectedness. We examined this hypothesis through a secondary analysis of a randomized controlled trial of IPT vs. Depression Care Management (DCM) for residual symptoms of late life depression (after partial or no response to an antidepressant; Reynolds et al., 2010). Methods: Older adults (age 60 or older) with unipolar major depression (n¼124) who were non/partial responders to a 6-week trial of 10 mg/day of escitalopram were randomly assigned to 16 weeks of continuation therapy: either 20mg escitalopram plus DCM or 20mg escitalopram plus DCM plus 16 sessions of IPT (however, some subjects received only 10 sessions of IPT due to changes in the initial protocol). Depression severity was measured with the Hamilton Rating Scale for Depression (HRSD; 17item). Social disconnectedness was measured with an item from the Interpersonal Support Evaluation List (ISEL; “When I feel lonely, I have people to talk to,” range:1¼definitely true to 4¼ definitely false). The presence of suicide ideation was measured with the HRSD suicide ideation item, dichotomized to reflect the presence or absence of suicide ideation (including thoughts that life is not worth living/wish for death) in the past week. We used generalized linear mixed models to examine the associations between both loneliness and depression and suicide ideation over the course of treatment. When examining effect of time the analyses used N¼59 who had complete data for variables of interest. Results: At randomization, 24 out of 124 subjects (19.35%) endorsed suicide ideation. Those who endorsed SI endorsed greater disconnectedness (mean¼1.96, sd¼1.16) compared to those who did not endorse SI (1.60, sd¼0.88; but it was not significantly different; Wilcoxon exact p¼0.19). Disconnectedness was found to decrease over treatment (start of randomization¼1.80, sd¼1.03; post¼1.61, sd¼.95, Wilcoxon signed rank p¼.048, n¼59), however there were no differences between treatment conditions. Suicide ideation was also found to decrease during the course of treatment (% at baseline 20.34; % post ¼ 5.08, F(1,58) ¼ 5.50, p¼.02), however, again there were no differences between treatment conditions. Improvement in disconnectedness was associated with improvement in depressive symptoms (spearman corr ¼ .26, n¼59, p¼.046). However, depression and disconnectedness were not significant predictors on suicide ideation over time. Conclusions: Among depressed older adults, treating residual depressive symptoms is associated with reductions in suicide ideation; however, there does not appear to be an added benefit of IPT over DCM. Our data provide limited support for the hypothesis that reductions in both disconnectedness and depression during depression-focused treatment may represent