Treatment of social anxiety with paroxetine: mediation of changes in anxiety and depression symptoms

Investigation of relationship patterns between co-occurring symptoms has greatly improved the efficacy of psychiatric care. Depression and anxiety often present together, and identification of primary vs secondary psychiatric symptoms has implications for treatment. Previous psychotherapy research investigating the relationship between social anxiety and depression, across social anxiety treatment, found that severity of social anxiety accounted for most of the change in depression severity across time. Conversely, severity of depression accounted for little variation in severity of social anxiety. The current investigation was conducted to extend these findings by examining this mediational relationship in a pharmacologic trial comparing paroxetine (n = 20) and placebo (n = 22). Social anxiety and depression severity were assessed weekly for 16 weeks. Consistent with the previous study, results indicated that social anxiety severity mediated most of the variance in depression severity, with little variance accounted for by a test of the reverse mediation. Surprisingly, this same pattern was also found in the placebo group. These findings suggest that this pattern of mediational relationships may be fundamental to social anxiety, rather than specific to treatment modality or secondary comorbidity.