Unlike other anxiety disorders, social anxiety disorder appeared to have a causal association with alcohol use disorder in a study of nearly 3,000 adult twins.
Prior research has shown that alcohol use disorders (AUD) frequently co-occur with social anxiety disorder and about 25% of people with AUD have social anxiety disorder, according to the study published in Depression & Anxiety.
“This combination is particularly debilitating, but it is not clear how the two disorders are associated,” Fartein Ask Torvik, PhD, from the department of mental disorders, Norwegian Institute of Public Health, Oslo, and colleagues wrote. “From a psychopharmacological perspective, it is likely that alcohol use produces anxiety, at least during withdrawal, and a few studies indicate that AUD causes anxiety. This could be true also for [social anxiety disorder]. On the other hand, a Mendelian randomization study found alcohol use not to cause symptoms of anxiety.”
Researchers examined whether social anxiety disorder was uniquely connected with alcohol use disorder more so than other anxiety disorders, how these connections developed over time and whether they could be causally associated.
Using the Composite International Diagnostic Interview, they evaluated 2,801 twins from Norway with psychiatric disorders — AUD, social anxiety disorder, generalized anxiety disorder, panic disorder, agoraphobia and specific phobias — between 1999 and 2004 (wave 1) and between 2010 and 2011 (wave 2). They used logistic regression analyses and multivariate biometric structural equation modeling to analyze the data.
The results showed that alcohol use disorder was much more common among participants with social anxiety disorder. Combining both waves of data, the researchers found that 15% of participants with social anxiety disorder had alcohol use disorder, compared with only 6% among those without social anxiety disorder.
Analyses revealed that each anxiety disorder was linked to alcohol use disorder, but the link was strongest for social anxiety disorder (OR = 4.68; 95% CI, 2.87-7.62).
After examining the phenotypic longitudinal connections between social anxiety disorder, other anxiety disorders and AUD, the researchers found that social anxiety disorder at wave 1 was linked to alcohol use disorder at wave 2; however, other anxiety disorders at wave 1 did not predict AUD at wave 2.
Torvik and colleagues also observed that the bestfitting biometric model included direct paths from social anxiety disorder to AUD, while the worst-fitting model included a path in the opposite direction. In addition, shared genetic risk factors explained the positive association between alcohol use disorder and other anxiety conditions, according to the results.
"Many individuals with social anxiety are not in treatment. This means that we have an underutilized potential, not only for reducing the burden of social anxiety, but also for preventing alcohol problems," Torvik said in a press release. "Cognitive behavioral therapy with controlled exposure to the feared situations has shown good results." – by Savannah Demko
Disclosure: The authors report no relevant financial disclosures.