Escitalopram normalizes brain activity related to social anxiety disorder, study finds

A study of individuals with social anxiety disorder in Finland found that the activation of the left inferior frontal gyrus region of the brain when processing negative versus positive adjectives referring to oneself is weaker than in healthy participants. After taking escitalopram, the activity in this region when processing negative adjectives increased. The research was published in Psychiatry Research: Neuroimaging.

Social anxiety disorder is a mental health condition characterized by an intense and persistent fear of social situations in which a person may be judged, embarrassed, or scrutinized by others. People with this disorder fear speaking in public, meeting new people, being observed while eating or working, and many similar situations. Their anxiety is disproportionate to the actual threat posed by the situation and persists even when the person recognizes that the fear is excessive.

Physical symptoms of social anxiety include blushing, sweating, trembling, rapid heartbeat, nausea, or difficulty speaking. Because of these symptoms, individuals suffering from social anxiety tend to avoid social situations altogether or endure them with significant distress.

Social anxiety disorder typically begins in adolescence or early adulthood, though it can occur at any age. It is distinct from ordinary shyness in that it causes marked impairment and significant suffering. The disorder is associated with negative self-beliefs, such as fears of appearing incompetent or being rejected.

Study author Rasmus Rinne and his colleagues wanted to examine the differences between individuals suffering from social anxiety disorder and healthy individuals during self-referential processing—i.e., while they are evaluating information in relation to themselves. They also wanted to see how escitalopram, a drug commonly prescribed to treat depression and anxiety disorders, changes this activity.

The final analysis included 35 individuals diagnosed with social anxiety disorder and 16 healthy individuals. Their average age was 25 years. 27 participants from the social anxiety group and 7 from the healthy group were women.

Participants with social anxiety disorder were randomly divided into two groups. One group was to receive 10mg of escitalopram per day for 7 days, while the other group received identical-looking tablets with no active ingredients for the same period (placebo). The study was double-blind, which means that participants did not know whether they were receiving escitalopram or placebo, and this was unknown to researchers directly interacting with them as well.

While undergoing functional magnetic resonance imaging (fMRI), participants completed a set of self-referential processing tasks. Study authors asked each participant to imagine overhearing a group talking about him or her using the adjective shown on the screen and to then respond depending on whether they saw the adjective as positive or negative.

There was a total of 60 adjectives describing positive and negative personality features and 20 neutral words (10 times the word “left” and 10 times the word “right”). A set of functional magnetic resonance images was also taken while participants were resting (resting-state fMRI).

The results showed that the social anxiety group showed a smaller difference in the activation of the left inferior frontal gyrus region of the brain when processing negative compared to positive adjectives than the healthy group. In the group that was taking escitalopram treatment, this difference was increased.

The difference in the level of activity in the precentral gyrus when processing negative and neutral adjectives was also lower in the social anxiety group.

“SAD [social anxiety disorder] may be associated with decreased activation of the left inferior frontal gyrus to negative self-referential social cues. Escitalopram may normalize such activation. As left inferior frontal gyrus has been linked to inner speech while working on self-reflection tasks, the increased activation might relate to reappraising negative social cues,” study authors concluded.

The study contributes to the scientific understanding of the effects of escitalopram in individuals with social anxiety disorder. However, the study was conducted on a relatively small sample. Results on larger samples might differ.

The paper, “Escitalopram normalizes decreased left inferior frontal gyrus activation in social anxiety disorder during self-referential processing,” was authored by Rasmus Rinne, Roope Heikkilä, Tuukka T Raij, Emma Komulainen, Jesper Ekelund, and Erkki Isometsä.