PERCEIVED SOCIAL SUPPORT MEDIATES ANXIETY AND DEPRESSIVE SYMPTOM CHANGES FOLLOWING PRIMARY CARE INTERVENTION

Cognitive and behavioral therapies and pharmacotherapies are well established as efficacious anxiety treatments. However, many patients remain symptomatic and do not achieve full remission. There is a need to move beyond analysis of outcome toward examination of how certain treatments (i.e., mechanisms) lead to change and for whom these changes occur (i.e., moderators).1 A better understanding of these factors can inform which therapy components are catalysts for symptom change, facilitating shedding of unnecessary therapeutic strategies and enhancement of essential elements. To date, most evaluation of treatment mediation of cognitive behavioral therapy (CBT) has focused on the extent to which cognitions and beliefs around anxiety and depression mediate symptom change.2 The current study takes a novel approach by examining perceived social support as a mediator of symptom change following evidence-based intervention for anxiety disorders. Social support can be emotional (i.e., a resource who listens and validates), instrumental (i.e., practical support), informational (i.e., advice), companionate (i.e., people with whom to socialize), and feedback (i.e., feedback on the community’s behavioral expectations).3 It is measured as perceived support, received support (i.e., how often supportive behaviors are received), and social integration (i.e., diversity/number of relationships). Perceived social support is the most commonly measured index of social support,4 given its ease of measurement and evidence that it is a better predictor of mental health and support utilization than other measures.5,6 The risk7–10 and protective effects11–15 of percieved social support on depression have been widely studied. Fewer studies have demonstrated these relations with anxiety as well, but the observed effects parallel the findings with depression.16–20 Perceived social support changes following treatment, and it has been studied as a moderator of treatment.21–23 Poor social support at baseline reduces the effect of treatment for depression,24,25 and treatment responders for depression are more likely to have better social support at baseline than nonresponders.26,27 Finally, there is some evidence for bidirectional relationships between perceived social support and symptoms of anxiety and depression. Specifically, there is evidence that social support predicts depression and depression predicts social support.9,10,28,29 Less is known about the directionality of perceived social support and anxiety. Given that perceived social support is a malleable construct, it is conceivable that enhanced perceptions of social support during an intervention may result in larger symptom change. If treatments for anxiety disorders are mediated by changes in perceived social support (or vice versa), then identification of treatment strategies targeting social support may facilitate treatment efficacy. The current study sought to assess these multidimensional changes over time in relation to treatment for anxiety. Using path analysis, we examined meditational effects of perceived social support on anxiety and depressive symptom changes in 1004 patients with anxiety disorders in primary care settings who were randomized to an evidence-based treatment of CBT and/or pharmacotherapy (CALM) or usual care for the treatment of anxiety disorders.30 Primary outcome publications2,31 already reported that the evidence-based CALM intervention had greater effects on 12- and 18-month outcomes than did usual care. The current study seeks to add to this knowledge base by examining whether changes in perceived social support explain some of the change in anxiety and depressive symptoms following evidence-based interventions compared to change that would normally occur in usual care. We hypothesized that the evidence-based intervention (compared to usual care) would have indirect effects on anxious and depressive outcomes via changes in social support over an 18-month period. Gender, race, and age have been examined as moderators of the relationship between perceived social support and emotional symptoms.7,32–37 Minority status and perceived social support interact to predict depressive symptoms.36,38 Similarly, gender and perceived social support interact to predict depression, such that only among females does perceived social support predict the disorder.32,34 Findings regarding the interaction effect of age and perceived social support on depression and anxiety have been mixed.7,39 Given the importance of peers, it is expected that younger age groups would demonstrate the greatest effect of social support on depression and anxiety. On account of these findings, it was hypothesized that our mediating effects would be strongest among females, minorities, and younger age groups. In sum, the primary goal of this study was to evaluate the degree to which perceived social support mediates anxious and depressive symptom changes following primary care intervention. We further explored moderators of the mediating pathways in order to establish for whom the mediating effects of perceived social support were strongest.