Increased beta-band salience network connectivity predicts 12-month longitudinal changes in depressive and anxiety symptom severity in young adults: a resting-state EEG study

The neural dynamics of large-scale brain networks that may be longitudinally associated with changes in depression and anxiety (DEPANX) symptom severity remain relatively understudied. We aimed to examine the relationship between the electrophysiological dynamics of the three-core resting-state networks (RSNs) and 12-month longitudinal changes in DEPANX symptom severity. Ninety-five participants (70 females; mean age: 21.35 ± 2.65 years) completed baseline (Time #1) and 12-month follow-up (Time #2) assessments. At Time #1 data about DEPANX symptoms and related variables (e.g., emotion regulation, familiarity for depression and anxiety) were collected. A resting-state electroencephalogram (EEG) recording was also collected. At Time #2 levels of DEPANX symptoms were assessed again. EEG data were analysed using the Exact Low-Resolution Electromagnetic Tomography software (eLORETA). We found that baseline SN connectivity, particularly bilateral insula beta coherence, was associated (r = 0.371; padjusted = 0.015) with DEPANX symptom changes over 12 months, whereas no comparable longitudinal associations were observed for other RSNs. When controlling for the presence of other variables, this connectivity pattern remained positively and independently associated with change in DEPANX symptoms (β = 0.328; p = 0.002). Our results suggest a key role of the bilateral insula connectivity in predicting 12-month longitudinal changes in DEPANX symptoms, with potential implications for prevention and treatment.