Implicit associations in social anxiety disorder: The effects of comorbid depression

Highlights

• We examined the implicit associations of patients with SAD with/without depression.

• Self-calmness associations were weaker in nondepressed SAD patients than controls.

• Self-calmness associations were weakest in SAD patients with depression.

• Self-rejection associations were weaker only in SAD patients with depression.

• Self-rejection differences were best accounted for by current depression.

Abstract

Implicit associations of the self to concepts like “calm” have been shown to be weaker in persons with social anxiety than in non-anxious healthy controls. However, other implicit self associations, such as those to acceptance or rejection, have been less studied in social anxiety, and none of this work has been conducted with clinical samples. Furthermore, the importance of depression in these relationships has not been well investigated. We addressed these issues by administering two Implicit Association Tests (IATs; Greenwald, McGhee, & Schwartz, 1998), one examining the implicit association of self/other to anxiety/calmness and the other examining the association of self/other to rejection/acceptance, to individuals with generalized social anxiety disorder (SAD, n = 85), individuals with generalized SAD and a current or past diagnosis of major depressive disorder or current dysthymic disorder (n = 47), and non-anxious, non-depressed healthy controls (n = 44). The SAD and SAD-depression groups showed weaker implicit self-calmness associations than healthy controls, with the comorbid group showing the weakest self-calmness associations. The SAD-depression group showed the weakest implicit self-acceptance associations; no difference was found between non-depressed individuals with SAD and healthy controls. Post hoc analyses revealed that differences appeared to be driven by those with current depression. The SAD-only and SAD-depression groups did not differ in self-reported (explicit) social anxiety. The implications of these findings for the understanding of SAD-depression comorbidity and for the treatment of SAD are considered.

Introduction

Social anxiety disorder (SAD) and major depressive disorder (MDD) are two of the most common mental disorders in the US (Kessler, Chiu, Demler, Merikangas, & Walters, 2005), with 12-month prevalence rates of 6.8% and 6.7%, respectively (Kessler, Berglund, et al., 2005). SAD and MDD often occur together, and SAD precedes MDD in approximately 70% of individuals with both disorders (Kessler et al., 1999, Schneier et al., 1992). In one study, individuals with SAD were at 3.5 times higher risk than those without to have a subsequent depressive disorder (Stein et al., 2001). In another study that followed adolescents into adulthood, the risk for depression was 2-fold in individuals with SAD compared to those without SAD and almost 3-fold compared to those with no anxiety disorder (Beesdo et al., 2007). Increasing our knowledge of depression comorbidity among persons with SAD is important because anxiety-depression comorbidity is associated with more chronic distress, greater risk of relapse, and more impaired psychosocial functioning than when the disorders present independently (e.g., Brown et al., 1996, Lewinsohn et al., 1995, Reich et al., 1993, Ruscio et al., 2008). One particular focus is understanding the role of information processing biases in SAD with and without depression.

Cognitive-behavioral models of SAD (e.g., Clark and Wells, 1995, Heimberg et al., 2010, Hofmann, 2007; see Wong, Gordon, & Heimberg, 2014, for a review and comparison of cognitive-behavioral models of SAD) posit that dysfunctional information processing contributes to the etiology and maintenance of the disorder. In fact, a large body of research documents the occurrence of one type of dysfunctional information processing, attentional bias toward social threat stimuli, in SAD (for a review, see Morrison & Heimberg, 2013; for a review of attentional bias toward threat stimuli in the anxiety disorders more generally, see Bar-Haim, Lamy, Pergamin, Bakermans-Kranenburg, & van Ijzendoorn, 2007). However, limited research suggests that the presence of depressive symptoms among individuals with social anxiety/SAD may alter the nature of this response.

One study looked at the impact of depressive symptoms on attentional bias among socially anxious individuals using an emotional Stroop task (Grant & Beck, 2006). Socially anxious individuals without depressive symptoms showed greater Stroop interference for threat words relative to neutral and positive words. However, the socially anxious-dysphoric group did not exhibit this bias. To our knowledge, only two other studies have addressed this problem (LeMoult and Joormann, 2012, Musa et al., 2003). Both administered a dot-probe task to individuals with SAD, SAD and a concurrent depressive disorder, and non-patient controls. Musa et al. found results largely consistent with Grant and Beck. Patients with SAD showed the expected bias (i.e., vigilance) toward social threat words. Patients with SAD and concurrent depression showed no such bias and appeared similar to controls. In contrast to the 500 ms threat cue presentation duration employed by Musa et al., LeMoult and Joormann presented threat cues for either 7 ms or 1000 ms. They found evidence of attentional avoidance of angry faces in the depressed SAD group compared to the non-depressed SAD group for the supraliminal presentation. However, the meaning of these results is less than clear, given that neither SAD group differed from controls on these trials. In addition, no evidence of attentional bias, either vigilance or avoidance, in either SAD group was detected for subliminally presented angry face cues, nor for positive, sad, or disgust faces at either presentation time.

Taken together, the pattern of results suggests that comorbid depression may nullify, or at least dampen, attentional biases associated with social anxiety at relatively brief exposures. When more time is permitted for stimulus processing, biases may be observed in the comorbid depression group, albeit in the opposite direction. Indeed, Mathews and MacLoed (2005) have suggested that early sensitivity to threat cues apparent in anxiety may by inhibited in depression, in which biases toward mood-congruent information are more commonly observed for stimuli that are presented for longer durations, potentially due to slower, more strategically directed processes such as rumination. Therefore, it appears prudent to consider whether concurrent depressive symptoms or depressive disorder have similar effects on other automatic cognitive biases in individuals with SAD.

Implicit associations are another important type of biased cognitive processing that is receiving attention in research on psychopathology. Implicit associations are thought to represent stable memory constructs developed over time that contribute to schemas about the self (Beevers, 2005, Haeffel et al., 2007). The IAT, developed by Greenwald, McGhee, and Schwartz (1998), examines implicit attitudes that someone holds regarding the relationship between a concept or category (e.g., flowers) and an attribute (e.g., goodness). The IAT has been widely used to examine attitudes regarding different racial groups, genders, and sexual orientations (e.g., Devos and Banaji, 2005, Jellison et al., 2004, Nosek et al., 2002). During the typical administration of the IAT, participants make a series of response choices involving a concept discrimination (e.g., flowers/insects) and an attribute discrimination (e.g., good/bad). Participants are instructed to respond rapidly with a right key press to items representing one concept and one attribute (e.g., flowers and good) and with a left key press to items from the remaining two categories (e.g., insects and bad). Participants then complete a second task in which key assignments for one of the pairs is switched. IAT response latencies are interpreted in terms of relative association strengths.¹ It is assumed that responses are more rapid when the concept and attribute mapped onto the same key are strongly associated, whereas responses are assumed to be relatively slower when the concept and attribute mapped on the same key are less closely associated.

The use of implicit measures, such as the IAT, may be particularly relevant with socially anxious individuals. Given that individuals with SAD experience heightened self-presentational concerns and fears of others’ evaluation, explicit self-report may yield an inaccurate or incomplete picture of their experiences. For example, it is a well-replicated phenomenon that persons with SAD report that they perform more poorly on behavioral tests than do other informants (e.g., Rapee and Lim, 1992, Rodebaugh et al., 2010, Rodebaugh and Rapee, 2005, Stopa and Clark, 1993). Implicit measures like the IAT may minimize – perhaps even circumvent – self-presentational biases and effects.

Several studies have used the IAT to study implicit associations in socially anxious individuals. de Jong (2002) administered the IAT to female undergraduates high and low in social anxiety, using concept categories of self (e.g., I, self) and other (e.g., their, them) and attribute categories of low-esteem (e.g., bad, stupid) and high-esteem (e.g., smart, valuable). Both high and low socially anxious groups performed faster categorizing self with high-esteem words than the reverse category pairings, although a significant interaction effect suggested that this pattern was stronger in the low socially anxious group. Similarly, another study found that high social anxiety participants did not exhibit negative implicit self-esteem; they responded more quickly to self-positive pairings than to self-negative pairings (Tanner, Stopa, & De Houwer, 2006). However, they did respond more slowly to self-positive pairings than those low in social anxiety. Notably, depressive symptoms did not impact IAT performance.

Some researchers have also examined responses to an IAT in which self or other is paired with rejection or acceptance, an area of clear concern to persons with social anxiety. A self-rejection IAT was used by Teachman and Allen (2007) in their study of perceived peer acceptance/rejection and its relationship to implicit and explicit fear of negative evaluation in adolescents. Adolescents more easily associated the self with acceptance than with rejection. Clerkin and Teachman (2010) examined the responses to the same IAT of socially anxious undergraduates to whom they provided training to modify implicit associations. Because all participants were socially anxious, it was not possible to compare their responses to those of a non-anxious sample, but similar to the adolescent sample of Teachman and Allen (2007), they more easily associated the self with acceptance than rejection. However, trained participants demonstrated strengthened self-acceptance associations and were more likely to complete an impromptu speech than students who had not received the implicit association training.

Few studies of implicit attitudes in social anxiety have examined clinical samples. Gamer, Schmukle, Luka-Krausgrill, and Egloff (2008) took a step in this direction when they recruited socially anxious students who completed four weeks of cognitive-behavioral group therapy at a university counseling center and were administered the IAT before and after treatment. Their responses were compared to non-anxious students who received no treatment. Participants were asked to categorize self-other words and anxiety-calmness words. Consistent with previous findings, socially anxious participants and non-anxious controls were faster in the self-calm pairings than in the self-anxiety pairings on both IAT administrations. However, socially anxious participants had weaker self-calm implicit associations than non-anxious controls at baseline. In addition, self-calm implicit associations had strengthened following treatment, as socially anxious participants no longer differed from controls.

To date, only one study has used the IAT to examine comorbid anxiety and depression in a diagnosed sample. Glashouwer and de Jong (2010) compared implicit beliefs in a mixed anxiety disorder group, those with a current diagnosis of MDD, those with an anxiety disorder and comorbid MDD, and a healthy control group. Participants were part of the Netherlands Study of Depression and Anxiety (Penninx et al., 2008). An IAT measured implicit self-anxiety associations. As with previous IAT studies, all groups exhibited faster reaction times on self-calm trials than on self-anxiety trials. The anxious group showed weaker self-calm associations than the depressed and control groups. The authors made no hypotheses regarding the effect of comorbidity on IAT scores, but the comorbid group had the weakest self-calm associations, although not significantly different from the anxious group (after Bonferroni correction).

Implicit associations have also been studied in relation to depression. For example, in the study by Glashouwer and de Jong (2010), an IAT was also administered in which self versus other words were paired with words representing depression or elation. Although depressed participants exhibited faster reaction times on self-elation trials than on self-depression trials, they also demonstrated weaker self-elation associations than the anxiety and control groups. Several additional studies have examined the implicit associations of persons at cognitive risk for depression (e.g., Haeffel et al., 2007, Steinberg et al., 2007) or previously depressed persons in reaction to a negative mood induction (e.g., Gemar et al., 2001, Meites et al., 2008). A full review of this literature is beyond the scope of this paper, but see a meta-analysis of implicit cognition in depression by Phillips, Hine, and Thorsteinsson (2010). The general conclusion to be drawn from these studies is that the implicit associations of self to positive attributes of depressed/formerly depressed/at-risk-for-depression persons are weaker than those of non-depressed persons. This is important to the current research because it supports the idea that comorbid depression may confer additional risk for cognitive bias in socially anxious persons, unlike the somewhat mixed findings for attentional bias toward social threat.

Research has demonstrated the utility of the IAT and provided the groundwork for understanding implicit associations in SAD. However, little is known about implicit associations in those with SAD and comorbid depression. Furthermore, no studies have examined implicit attitudes in a sample of clinically diagnosed, treatment-seeking individuals with SAD and depression. Of the studies reviewed above, the majority have been conducted with analog samples, and only two have examined the impact of depressive symptoms. Tanner et al. (2006) found no effect of depression on the implicit associations of socially anxious persons. Glashouwer and de Jong (2010) examined a mixed anxiety group and did not focus specifically on SAD. Given the high comorbidity of SAD and MDD, and the impairment associated with this comorbidity, it is crucial that we increase our understanding of the associated cognitive processes so that we can expand our theoretical models and enhance our treatment approaches.

One step toward this, and a goal of the current study, was to examine implicit associations among treatment-seeking patients with SAD and comorbid depression (i.e., MDD or dysthymia), compared to patients with SAD but no history of depression, and to healthy controls. We used two IATs, one measuring associations of self/other with anxiety/calmness and the other measuring associations of self/other with rejection/acceptance.

Based on results from previous studies, we hypothesized that individuals with SAD would exhibit weaker self-calm associations than healthy controls. We also hypothesized that the comorbid group would exhibit weaker self-calm associations than healthy controls. Studies on implicit associations in depression suggest that the comorbid group might have even weaker self-calm associations than the SAD group, but the empirical support for this hypothesis is not strong.

The self-rejection IAT used here was similar to the one used by Clerkin and Teachman (2010) and Teachman and Allen (2007) and has yet to be studied in a clinical sample of persons with SAD. Our interest in this IAT comes in part from the literature on interpersonal rejection sensitivity (e.g., Downey and Feldman, 1996, Leary, 2006). Those with high levels of interpersonal rejection sensitivity are thought to have high expectations for rejection by others and to place high value on being accepted (Downey & Feldman, 1996). Rejection sensitivity has been primarily studied as a risk factor for depression (e.g., Ayduk et al., 2001, Boyce and Parker, 1989), but it may be an underlying personality trait in those with social anxiety as well (Harb, Heimberg, Fresco, Schneier, & Liebowitz, 2002). We sought to explore how a clinical sample would perform on the self-rejection IAT, and whether there would be differences between the SAD and SAD-depression groups, given the potential importance of rejection sensitivity in both social anxiety and depression.