Journal of Anxiety Disorders 33 (2015) 103–109 Contents lists available at ScienceDirect Journal of Anxiety Disorders Risk profiles for poor treatment response to internet-delivered CBT in people with social anxiety disorder Maria Tillfors a,∗ , Tomas Furmark b , Per Carlbring c , Gerhard Andersson d,e a Center for Health and Medical Psychology, JPS, Psychology, Örebro University, Sweden b Department of Psychology, Uppsala University, Sweden c Department of Psychology, Stockholm University, Sweden d Department of Behavioural Sciences and Learning, Linköping University, Sweden e Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institutet, Stockholm, Sweden a r t i c l e i n f o Article history: Received 18 February 2015 Received in revised form 20 May 2015 Accepted 25 May 2015 Available online 1 June 2015 Keywords: Social anxiety disorder Social avoidance Depressive symptoms Guided internet-based CBT Risk factors Cluster analysis a b s t r a c t In social anxiety disorder (SAD) co-morbid depressive symptoms as well as avoidance behaviors have been shown to predict insufficient treatment response. It is likely that subgroups of individuals with different profiles of risk factors for poor treatment response exist. This study aimed to identify subgroups of social avoidance and depressive symptoms in a clinical sample (N = 167) with SAD before and after guided internet-delivered CBT, and to compare these groups on diagnostic status and social anxiety. We further examined individual movement between subgroups over time. Using cluster analysis we identified four subgroups, including a high-problem cluster at both time-points. Individuals in this cluster showed less remission after treatment, exhibited higher levels of social anxiety at both assessments, and typically remained in the high-problem cluster after treatment. Thus, in individuals with SAD, high levels of social avoidance and depressive symptoms constitute a risk profile for poor treatment response. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction Randomized controlled trials (RCTs) show that cognitive behav- ioral therapy (CBT) in various formats (individual, group, as well as guided internet-delivered self-help) is effective for people with social anxiety disorder, or SAD (e.g., Andersson, Carlbring, & Furmark, 2014; Clark et al., 2006; Heimberg, 2002; Mayo-Wilson et al., 2014). However, even with the best psychological treatments, more than one in four do not improve sufficiently (e.g., Ponniah & Hollon, 2008), and this heterogeneity in treatment response is worthy of further investigation. It is a rule rather than an excep- tion that people have several mental health and somatic problems (Harvey, Watkins, Mansell, & Shafran, 2004), and co-morbidity is an important factor to consider in relation to treatment response. Depression and other anxiety disorders are common co-morbid problems in people with SAD (Kessler, Chiu, Demler, Merikangas, & Walters, 2005; Rapee & Spence, 2004; Schneider, Johnson, Horning, Liebowitz, & Weissman, 1992). Moreover, use of dysfunctional emotion regulation strategies like avoidance behaviors (both on ∗ Corresponding author at: JPS, Psychology, Örebro University, 701 82 Örebro, Sweden. Tel.: +46 19 30 39 59. E-mail address: maria.tillfors@oru.se (M. Tillfors). an overt and a covert level) are common in SAD. Such behaviors are positively related to clinical severity, and have been shown to maintain the disorder (Harvey et al., 2004). Importantly, it is likely the inflexible use of dysfunctional emotion regulation strategies, like avoidance behaviors, to manage intense anxiety in a range of different social situations that maintains SAD rather than the level of anxiety per se (Harvey et al., 2004). Hence, both co-morbidity and avoidance behavior could underlie heterogeneity in treatment response in individuals with SAD. Indeed, co-morbid depressive symptoms as well as high lev- els of avoidance behavior have previously been shown to predict suboptimal treatment response in people with SAD (e.g., Eskildsen, Hougaard, & Rosenberg, 2010; Hedman et al., 2012; Nordgreen et al., 2012; Rodebaugh, Holaway, & Heimberg, 2004), although the results regarding depressive symptoms have been mixed (Eskildsen et al., 2010; Nordgreen et al., 2012; Rodebaugh et al., 2004). It can further be hypothesized that a combination of risk factors may particularly increase the risk for poor treatment outcome, possi- bly explaining the mixed findings regarding depressive symptoms as a treatment predictor. In other words, there may be subgroups of individuals with different profiles of risk factors for poor treat- ment response. However, when examining such risk profiles we cannot rely only on variable-oriented methods such as regression based approaches, which are commonly used in analyses of RCTs. http://dx.doi.org/10.1016/j.janxdis.2015.05.007 0887-6185/© 2015 Elsevier Ltd. All rights reserved.