Efficacy of intermittent theta burst stimulation (iTBS) in bipolar depression in a public setting

Abstract Background/Introduction: Intermittent theta-burst stimulation (iTBS) on the left dorsolateral prefrontal cortex (DLPFC) has shown meta-analytic evidence of its efficacy in unipolar treatment resistant depression (TRD). However, the usefulness of iTBS in patients with bipolar depression has not yet been stablished. Methods: This is a follow-up study of n=12 patients with bipolar resistant depression with TRD who received adjuvant iTBS (600 pulses) on the left for 4-6 weeks in a public hospital in Spain. Self-administered and hetero-administered measures of affective symptomatology, anxiety, insomnia, apathy functioning and neurocognition were collected before and after iTBS. Weekly assessments of affective symptomatology were performed during the treatment period. The change in symptomatology was analyzed with a linear model of HDRS repeated measures, using time (baseline and final HDRS) as the intra-subject factor. Models were controlled for severity and resistance to treatment. T-tests were performed for paired data (baseline-final) for the rest of the functionality and mood variables. Predictive logistic regression models of response and remission to treatment and post-hoc comparisons of patients with clinical response and remission were performed. Results: Patients received a mean of 30.4 iTBS sessions. Analyses revealed significant differences between baseline and final HDRS (mean change = 60,11%) without influence of baseline treatment resistance, or diagnosis (BD I or BD II). There was a significant improvement in self-applied and hetero-applied variables of mood, functioning, and anxiety and neurocognition. The response and remission percentages of the affective symptoms were 66,7% and 58,3%, respectively. There were 2 hypomanic switches. Post-hoc analyzes showed a higher percentage of remitters among patients with comorbid pathological personality traits and a seasonal pattern of depressive phases. Conclusion: The results suggest the clinical utility of acute iTBS treatment in patients with bipolar depression. Research Category and Technology and Methods Clinical Research: 10. Transcranial Magnetic Stimulation (TMS)