The predictive value of cortisol in psychodynamic psychotherapy for social anxiety disorder: Extended results of the SOPHONET-Study.

Psychotherapy is an effective treatment for anxiety disorders (AD), yet a vast majority of patients do not respond to therapy, necessitating the identification of predictors to enhance outcomes. Several studies have explored the relationship between stress response and treatment outcome, as a potential treatment mechanism. However, the latter remains under-researched in patients with social anxiety disorder (SAD). We studied N = 29 patients undergoing psychodynamic psychotherapy (PDT) within the SOPHONET-Study. Stress reactivity (i.e., area under the curve with respect to the increase; AUCi) was induced by a standardized psychosocial stressor (Trier Social Stress Test; TSST) and assessed by means of adrenocorticotropic hormone (ACTH), blood and salivary cortisol samples before (t 1 ) treatment. Samples of these biomarkers were taken -1 min prior stress exposure and six more blood samples were collected post-TSST ( + 1, + 10, + 20, + 30, + 45, + 60 min.). The participants were diagnosed with SAD based on the Structured Clinical Interview for DSM-IV (SCID) and completed the Liebowitz Social Anxiety Scale as well as the Beck Depression Inventory before (t 1 ) and after psychotherapy (t 2 ). Pre-treatment stress reactivity significantly predicted changes in depression (salivary p < 0.001 and blood cortisol p = 0.001), as well as in avoidance behavior (blood cortisol p = 0.001). None of the biomarkers revealed significant results in fear or in the total LSAS-scores, except for ACTH with a trend finding (p = 0.06). Regarding therapy success, symptoms of social anxiety (p = 0.005) and depression (p < 0.001) were significantly reduced from pre (t 1 ) to post-treatment (t 2 ). Our study showed that stress reactivity pre-treatment may serve as a predictor of psychotherapy outcome. In this regard, alterations in stress response relate to changes in symptoms of social anxiety and depression after PDT. This implies that patients with chronic stress might benefit from a targeted interventions during psychotherapy, especially to manage fear in social contexts.