Decreased temporal variabilities of functional connectivities in insula and lingual gyrus are associated with better early treatment response in patients with panic disorder.

Background: Panic disorder is a common disabling condition with limited biomarkers. We aimed to explore the diagnostic and treatment response prediction value of functional temporal variability in people with panic disorder.

Methods: Patients with panic disorder and healthy controls received resting-state functional magnetic resonance imaging scans and assessments. After 2 weeks of treatment, the patients with panic disorder were divided into remitted (RPD; n = 39) or nonremitted (NRPD; n = 43) subgroups. Baseline temporal variability was analyzed between the panic disorder and control groups as well as between RPD and NRPD subgroups.

Results: Our sample included 82 patients with panic disorder (39 RPD, 43 NRPD) and 105 controls. The panic disorder group showed decreased temporal variability in the left posterior cingulate gyrus (PCG), right lingual gyrus, right fusiform gyrus, and right thalamus (all p < 0.05, Bonferroni-corrected). A combination of variability in the lingual gyrus, PCG, and thalamus had optimal predictive value for distinguishing between the panic disorder and control groups (area under the curve = 0.776, sensitivity = 0.781, specificity = 0.732). In addition, the RPD subgroup showed significantly lower temporal variability in the left insula, right PCG, and bilateral lingual gyrus than the NRPD subgroup and control group (all p < 0.05, Bonferroni-corrected). Variability in the left insula and left lingual gyrus negatively correlated with the reduction rate of panic symptoms (all p < 0.05, Bonferroni-corrected).

Limitations: Functional brain images were collected only at baseline and may have been affected by medication use. Also, the follow-up period was only 2 weeks; sustained clinical remission may require longer follow-up.

Conclusion: Combining lingual gyrus, PCG, and thalamus temporal variability alterations helped distinguish patients with panic disorder from healthy controls. The temporal variability in the insula and lingual gyrus are potential biomarkers for the treatment of panic disorder.