The American writer and philosopher Henry David Thoreau once said, “Public opinion is a weak tyrant when compared with our own private opinion.”

Worry about how others will evaluate us is an almost universal human experience. While most of us are able to overcome these worries, for people with social anxiety disorder (SAD), the fear of being scrutinized does indeed become a tyrannical force.

The core feature of SAD is an intense fear of humiliation, embarrassment, rejection, or offending or boring others in situations such as social interactions, when being observed by other people, and when performing (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, VA: American Psychiatric Association (APA); 2013).

For patients with SAD, going on a date or attending a party with unfamiliar people, giving a speech at a wedding or at a work meeting, eating or drinking in front of others, and even urinating in a public bathroom can cause extreme worry before and during the activity. Their anxiety is further compounded by excessive worry about others being able to see the anxiety (eg, due to sweating, a shaking voice, trembling hands, or blushing).

People with SAD often go to great lengths to avoid detection of their internal state. For example, patients who are worried about others noticing them sweating may carry a napkin or towel around in order to wipe sweat away. Patients with SAD either endure these situations despite significant discomfort, or avoid them altogether.

Understandably, this leads to significant occupational and social dysfunction. For instance, people may opt out of pursuing promotions at work that would entail public speaking or meeting new clients, and they often experience difficulty meeting new friends or developing romantic relationships.

Defining SAD

Since its introduction in the DSM-III in 1980 as "social phobia," the diagnosis of SAD has evolved from being considered a circumscribed, highly specific phobia (eg, a person only experiences anxiety when being interviewed but not in other circumstances) to our current understanding of a broader, more generalized anxiety affecting most social relationships and interactions.

In fact, the vast majority of patients with SAD struggle with anxiety in numerous settings. One study showed that 93% of people with SAD felt fearful in three or more social situations, and only 2.7% identified just one social situation as causing extreme anxiety (Grant BF et al, J Clin Psychiatry 2005;66(11):1351–1361).

Therefore, in DSM-5, released by the APA in late 2013, the name has been changed from social phobia to social anxiety disorder (subtitled social phobia). There does seem to be a small subgroup of people with SAD whose fear is limited to performance settings, and a “performance only” specifier was added to DSM-5 (Bögels SM et al, Depress Anxiety 2010;27(2):168–189). This is most relevant for people who are musicians, athletes, or performers, where performance anxiety is likely to have a large negative impact on their livelihood.

SAD has a lifetime prevalence of 5%–8.6% (Grant et al, op.cit; Burstein M et al, J Am Acad Child Adolesc Psychiatry 2011;50(9):870–880). It is slightly more common in women than in men, in contrast to most other anxiety disorders, which are much more prevalent in women than in men (McLean CP et al, J Psychiatr Res 2011;45(8):1027–1035).

For those of us working with children and adolescents, it is particularly important to remember that the onset is typically in childhood and adolescence (the average age is 15 years old, but many people report very early onset before five years old). Onset after early adulthood is rare (Grant et al, op.cit). To be diagnosed with SAD, children must experience anxiety around both their peers and adults, beyond the standard social discomfort that is common in adolescents.

Additionally, since children’s capacity to report feelings like fear and anxiety is developmentally limited, their worry may be evident by behaviors such as crying, tantrums, clinging, or failing to speak in social situations. (It’s important to consider selective mutism as an alternative diagnosis for a child who refuses to speak.)

Notably, there is often a significant delay between onset of symptoms and treatment, with one sample reporting an average delay of 12 years (Grant et al, op.cit). While the DSM-5 includes a suggested (but not required) duration of at least six months, most people will have suffered for much longer before seeking treatment.

Comorbidities and Other Possible Diagnoses

People with SAD have a significantly higher rate of several other disorders. Nearly 50% meet criteria for another anxiety disorder and approximately 40% have a comorbid mood disorder. Substance use disorders are also significantly more common in those with SAD: about 13% have an alcohol use disorder, 5% have another drug use disorder, and 27% have nicotine dependence (Grant et al, op.cit).

Social anxiety may present as a symptom in the context of (and be better explained by) several other disorders. For example, people with Asperger’s disorder often experience discomfort in social settings. They have impairment in nonverbal behaviors that negatively impact their social interactions, and they are often aware that they interact in a way that is different from most people.

However, they do not necessarily experience the classic physiologic symptoms (and worry about them) that characterize SAD. While they may be aware of some impairment, social anxiety itself is not a symptom.

Therapists should also consider the possibility of avoidant personality disorder for a patient presenting with social phobia symptoms. These patients experience extreme self-consciousness and fear of rejection, and tend to be extremely critical of themselves in social interactions. They avoid close relationships unless they feel certain they will not be ridiculed.

It can be very difficult to distinguish those with severe, chronic, generalized social phobia from those with avoidant personality disorder. Both are understandably socially and occupationally impaired, and both experience social anxiety as highly ego dystonic. One clue may be that those with SAD are usually primarily focused on their own internal state. In addition to this trait, people with avoidant personality disorder also ttend to pay very close attention to others' behavior and reactions, to monitor for signs of rejection.

Finally, it’s important to consider whether social anxiety is better explained by another anxiety or a mood disorder. For instance, hypersensitivity to rejection is often present during episodes of major depression.

Another example is someone with post-traumatic stress disorder who feels hypervigilant in public or crowded places. This person may describe hyperarousal (eg, tremulous hands, shaking hands or voice) that is quite similar in nature, but different in origin, to that seen in SAD. These things should be kept in mind when evaluating patients for social anxiety disorder.