This article analyzes modern theoretical and conceptual models of social anxiety disorder (SAD) (cognitive, metacognitive, psychopathological) with a view to determine specific features of psychological mechanisms of disorders studied in various approaches, to identify similarities and differences in conceptual SAD models, their heuristic specifics and efficiency in the diagnostics and practice of psychological intervention. The authors demonstrated psychopathological mechanisms related to SAD origin and development shows the effectiveness of psycho-pathological approach to diagnostics and therapy. Analyzing the psychopathological approach, the authors revealed that the key mechanisms, which cause SAD, are specific disturbances of target regulation of mental activity and mediation of anxiety during evaluation, changes in the "motive-goal-means" system, social behavior aberrations and distortion of selectivity in mental activity. The comparative analysis revealed that maximum diagnostic and therapeutic efficacy is achieved during combined application of the models in the psychological practice.