Comorbid anxiety in depression and rTMS treatment response: A retrospective study

Few studies have examined the relationship between anxiety and response to repetitive transcranial magnetic stimulation (rTMS) in patients with unipolar depressive disorder (UDD) and bipolar depressive disorder (BDD). The primary aim of this study was to investigate the correlation between anxiety symptoms and the response to rTMS in individuals with comorbid anxiety, in both UDD and BDD patients. The secondary aim was to evaluate the efficacy of rTMS in reducing depressive symptoms, anxiety, and different subtypes of anxiety disorder.

A total of 379 outpatients (214 UDD, 165 BDD) underwent 20 sessions of either right unilateral low-frequency rTMS or sequential bilateral rTMS targeting the dorsolateral prefrontal cortex (DLPFC). Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI-II) were used for assessment.

Binary logistic regression analysis indicated that pre-treatment physical anxiety scores showed a negative correlation with rTMS response, while subjective anxiety scores were positively associated. Distinct and overlapping response profiles for UDD and BDD patients with comorbid anxiety were identified based on anxiety symptoms. Predictive values for the BDD group were more reliable than those for the UDD group (PPV: 75 %, NPV: 77 %). Moreover, both unilateral and bilateral rTMS significantly reduced depressive symptoms as well as physical, subjective, and panic-related anxiety symptoms.

The findings suggest that in both UDD and BDD, physical anxiety symptoms are linked to less response to rTMS, whereas subjective anxiety symptoms are associated with more response. Future prospective studies are required to confirm the predictive value of anxiety symptoms in UDD and BDD patients who suffer from comorbid anxiety.