Effects of Anodal Left DLPFC tDCS on Panic Severity in Panic Disorder Patients With and Without Comorbid Rhinosinusitis and Nasal Septum Deviation.

PURPOSE: Panic disorder (PD) is characterized by recurrent, unexpected panic attacks and impaired top-down modulation of the fear circuitry, notably left dorsolateral prefrontal cortex (DLPFC) hypoactivity and dysregulation of respiratory-panic pathways. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that modulates cortical excitability by delivering low-intensity electrical currents through scalp electrodes. Chronic rhinosinusitis (CRS) and nasal septum deviation (NSD) commonly disrupt nasal breathing and sleep while increasing anxiety vulnerability. This study evaluated the efficacy and long-term stability of anodal tDCS over the left DLPFC in reducing panic severity in PD patients with versus without comorbid CRS or NSD.

METHODS

Sixty-six adults with DSM-5 PD were purposively allocated to PD-only (n = 27), PD + CRS (n = 26), and PD + NSD (n = 13) groups. All received 25 sessions of anodal tDCS (2 mA, 20 min; anode F3, cathode FP2). Panic severity was assessed with the Panic Disorder Severity Scale (PDSS) at baseline, post-treatment, and 6- and 12-month follow-ups. The data were analyzed using mixed ANOVA with Bonferroni-corrected post-hoc tests.

FINDING: A significant time × group interaction was observed (F = 7.65, p < 0.001, ηp 2 = 0.20). All groups showed large, immediate reductions in PDSS scores (57%-65%, p < 0.001). Treatment gains were fully maintained at 12 months in the PD-only and PD + CRS groups, whereas the PD + NSD group exhibited statistically and clinically significant partial relapse by 12 months (p = 0.022 versus both other groups).

CONCLUSION

Anodal left-DLPFC tDCS is highly effective and generally durable for panic disorder. However, untreated nasal septum deviation substantially compromises long-term stability, probably via persistent interoceptive stress and respiratory dysregulation. Systematic screening and management of upper-airway patency are recommended to optimize sustained outcomes.