Comorbidity: Social anxiety disorder and psychiatric comorbidity are not shy to co-occur

Social anxiety disorder is one of the most prevalent psychological disorders in the United States of America (Schneier et al., 1992). Psychiatric comorbidity within SAD is highly prevalent as well, and commonly includes anxiety, mood, personality and substance use disorders. Research has documented the impact of psychological comorbidities on SAD, which includes increased symptom severity and decreased functional impairment and overall quality of life (Klein Hofmeijer-Sevink et al., 2012; Wittchen et al., 2000). Furthermore, comorbidity may impact a clinician's ability to make accurate diagnoses and discover etiological causes, and complicates case conceptualizations and treatment plans (Marrie et al., 2009). The current chapter highlights the differences that exist between disorders that are commonly comorbid with SAD in an effort to illustrate the unique and distinct impact of each disorder-type on SAD. We expect this approach will hold important clinical utility.