Anxiety disorders account for the maximum cases of mental disorders among adolescents. However, only half of the pediatric patients with anxiety disorders respond to the first-line pharmacologic treatments, i.e. selective serotonin reuptake inhibitors (SSRIs).

Thus this population warrants the determination of the neurofunctional targets of SSRIs and pretreatment or early-treatment neurofunctional markers of SSRI treatment response. 

A recent study collected Pretreatment and early-treatment (2 weeks into treatment) functional magnetic resonance imaging during a continuous processing task with emotional and neutral distractors in 36 adolescents with a generalized anxiety disorder (GAD) who were randomized to 8 weeks of double-blind escitalopram or placebo. 

Generalized psychophysiological interaction analysis examined the functional connectivity of the amygdala while patients viewed emotional pictures. Full-factorial analysis investigated the treatment effect of escitalopram on amygdala connectivity. Correlation analyses explored the association between pretreatment, early (week 2) treatment-related connectivity and the treatment response (improvement in anxiety) at week 8. 

Contrasting placebo, during emotion processing, escitalopram improved emotional processing speed and negative right amygdala-bilateral ventromedial prefrontal cortex (vmPFC) and positive left amygdala-right angular gyrus connectivity. Initial amygdala-vmPFC connectivity and escitalopram-induced raised amygdala-angular gyrus connectivity at week 2 forecasted the magnitude of succeeding progress in anxiety symptoms. 

Thus amygdala connectivity to hubs of the default mode network denotes a target of acute SSRI treatment. Likewise, pretreatment and early-treatment amygdala connectivity may be used as a biomarker of SSRI treatment response in adolescents with GAD.

Neuropsychopharmacol. 47, 1081–1087 (2022). https://doi.org/10.1038/s41386-021-01186-0