Social anxiety is a very common disorder and is especially common among individuals with substance abuse or dependence (substance use disorders [SUDs]). Several epidemiologic surveys have estimated the prevalence of social anxiety disorder (also called social phobia) in the general population to be between 3% and 13% (Kessler et al., 1994; Schneier et al., 1992). However, in SUD clinics, the rate is significantly greater. Zimmermann and colleagues (2004) surveyed 150 individuals seeking treatment for an SUD in Switzerland, using the clinician-administered Leibowitz Social Anxiety Scale (LSAS), and found that 20% of the participants screened positive for generalized social phobia and 42.6% screened positive for nongeneralized social phobia. Myrick and Brady (1997) evaluated 158 individuals entering an outpatient clinical treatment trial for cocaine dependence and found that 13% met criteria for social anxiety disorder. Finally, of 159 individuals seeking treatment for heroin dependence, 18% to 25% screened positive for social anxiety disorder (Grenyer et al., 1992).
In addition to social anxiety being prevalent in the drug treatment setting, addiction is also commonly found in anxiety treatment clinics and may be responsible for resistance to traditional anxiety disorder treatments (Coplan et al., 1993). In Australia, 146 individuals seeking treatment for either social phobia or panic disorder at an anxiety treatment program were evaluated (Page and Andrews, 1996). The researchers hypothesized that they would see higher rates of sedative-hypnotic abuse and dependence among the participants with panic disorder and higher rates of alcohol(Drug information on alcohol) misuse among the individuals with social phobia. They found, however, that both the participants with social phobia and those with panic disorder had a rate of sedative-hypnotic misuse that was eight times that of the general population. Also, only the participants with social phobia had elevated rates of an alcohol use disorder (Page and Andrews, 1996).
When two disorders co-occur, like social anxiety disorder and addiction, causality (if it exists) is often difficult to unravel. For example, chronic alcohol or illicit drug use can be anxiogenic. Some treatment providers would argue that if an individual with an anxiety disorder and co-occurring substance dependence has successful treatment for the substance dependence, recovering into a sober lifestyle, their anxiety disorder will also be ameliorated. This line of reasoning would be based on the assumption that the substance dependence preceded the anxiety disorder and the direction of causality would be from addiction to anxiety. As a disorder co-occurring with substance dependence, social anxiety disorder most likely does not fit into these assumptions. The average age of onset of social anxiety disorder is in the mid-teens (Schneier et al., 1992), at a time when social interpersonal attitudes and relationships are being formed--also a time when experimentation with illicit drugs and alcohol generally would begin. The average age of alcohol dependence, for example, is roughly a decade later, in the mid-20s (Schuckit et al., 1998), making the direction of causality, if it exists, more likely to be from social anxiety to substance dependence.