Social fear conditioning: a novel and specific animal model to study social anxiety disorder

Social anxiety disorder (SAD) is a major health concern with high lifetime prevalence. The current medication is rather unspecific and, despite considerable efforts, its efficacy is still unsatisfactory. However, there are no appropriate and specific animal models available to study the underlying etiology of the disorder. Therefore, we aimed to establish a model of specific social fear in mice and use this social fear conditioning (SFC) model to assess the therapeutic efficacy of the benzodiazepine diazepam and of the antidepressant paroxetine; treatments currently used for SAD patients. We show that by administering electric foot shocks (2-5, 1 s, 0.7 mA) during the investigation of a con-specific, the investigation of unfamiliar con-specifics was reduced for both the short- and long-term, indicating lasting social fear. The induced fear was specific to social stimuli and did not lead to other behavioral alterations, such as fear of novelty, general anxiety, depression, and impaired locomotion. We show that social fear was dose-dependently reversed by acute diazepam, at doses that were not anxiolytic in a non-social context, such as the elevated plus maze. Finally, we show that chronic paroxetine treatment reversed social fear. All in all, we demonstrated robust social fear after exposure to SFC in mice, which was reversed with both acute benzodiazepine and chronic antidepressant treatment. We propose the SFC model as an appropriate animal model to identify the underlying etiology of SAD and possible novel treatment approaches.