A new study of social anxiety and avoidant personality disorders finds that while genetics play a significant role in developing the conditions over time, environmental factors matter most in the short term.
For over a decade, researchers from the Norwegian Institute of Public Health followed approximately 3,000 Norwegian twins to find out more about how mental disorders develop over time.
“The results show a surprisingly high heritability of the long-term risk of developing social anxiety,” said Dr. Fartein Ask Torvik, a researcher in the Department of Genetics, Environment, and Mental Health at the institute.
It has long been known that both genetics and the environment play a role in the development of social anxiety, but researchers have been previously unaware of the strong effect of genetic factors over time.
Twins were studied so that researchers can see the extent to which the disorders are influenced by genetic and environmental factors. The women were interviewed twice: once when they were in their 20s and once in their 30s.
“Social anxiety is known to have an early onset, often in adolescence. Social anxiety usually does not appear after your mid-20s if you have not had it before,” said Torvik.
In the study, researchers found that just under four percent of participants had social anxiety disorder in their twenties. Another 10 percent had symptoms that did not qualify for a diagnosis.
Ten years later, five percent and just under nine percent respectively had social anxiety disorder or its symptoms. It was not necessarily the same people who had social anxiety in their 20s and 30s.
“The anxiety was less stable than expected. Two-thirds of those who had social anxiety when they were interviewed in their 20s no longer met the diagnostic criteria when they were interviewed 10 years later. It appears to fluctuate for individuals,” said Torvik.
“However, the prevalence was not lower in the 30s than in the 20s, since other people had the disorder again when they were interviewed,” he added.
Social anxiety is the fear of being negatively evaluated in social situations. Many people experience this occasionally and it is considered to be normal. Anxiety only qualifies as a diagnosis when it becomes marked enough to prevent normal social interactions.
“Social anxiety disorder or social phobia can lead to persistent and significant distress and impairment in important areas of functioning,” said Torvik.
Avoidant personality disorder often occurs together with social anxiety, but the study suggests that this personality disorder is not the same as strong social anxiety.
Certain practices can mask external displays of social anxiety but these behaviors may be detrimental over the long run.
“The risk of developing social anxiety is associated with avoidant personality traits. These traits can lead to avoiding the feared situations. Many also use safety behaviors to cover or control their anxiety. In the long term this could lead to more anxiety,” says Torvik.
When the researchers looked at the long-term risk of developing social anxiety, they discovered the risk is strongly influenced by genetic factors.
This is probably because personality traits that predispose to the disorder, such as introversion and low emotional stability, are influenced by genetics.
If you have both of these traits, the risk of developing social anxiety is high. However, at any particular moment, the environment will have the greatest impact on whether you have social anxiety.
The events that affect social anxiety in the twenties have little effect in the thirties. The environment has the strongest effect in the short term, and the impact of most experiences will pass.
When researchers looked at the causes of stability and change over time, they found that the genetic risk was persistent and contributed to the stability, while the environment largely contributed to change.
“Social anxiety is highly heritable. While environmental factors are most significant in the short term, your genes play a crucial role over time,” said Torvik.
“This means that the impact of environmental events, such as being bullied or losing a job, is of limited duration. The effect of the events that cause social anxiety at one point will pass. The fact that social anxiety disorder is so unstable should give hope for those who are struggling with it,” he said.
The study was conducted by researchers at the Norwegian Institute of Public Health, with collaborators at the University of Oslo and Virginia Commonwealth University.