Internet-delivered cognitive behavior therapy for social anxiety disorder has previously demonstrated to target and affect the brain´s fear network, typically neural response in the amygdala ameliorate after effective psychological treatment. Commonly, neuroimaging studies have performed brain imaging at pre- and post-intervention, yet, longitudinal study designs including several repeated measures of neural response over the course of treatment are currently missing in anxiety disorder. In the current study the participants will undergo magnetic resonance imaging (MRI) at four occasion. a) Twice before treatment initiation (9 weeks apart), b) at week 4 (during treatment), c) and directly after treatment termination.