Efficacy, Safety, and Tolerability of Theta-Burst Stimulation in Mixed Depression: Design, Rationale, and Objectives of a Randomized, Double-Blinded, Sham-Controlled Trial

Distractibility, anxiety, irritability, and agitation symptoms are associated with the severity of depressive and manic symptoms in mixed depression

OBJECTIVE

To explore whether there is an association between distractibility, anxiety, irritability, and agitation (DAIA) symptoms and the severity of depressive and manic symptoms.

METHODS

Patients with unipolar and bipolar disorder (I and II) and mixed depression were evaluated. DAIA symptoms were assessed using previously described definitions.

RESULTS

The full analysis set comprised 100 patients. The severity of depressive symptoms in mixed depression, assessed by Montgomery-Åsberg Depression Rating Scale (MADRS), was significantly associated with the presence of two or more DAIA symptoms in the bipolar sample, influenced mainly by anxiety. The severity of manic symptoms in mixed depression, assessed by Young Mania Rating Scale (YMRS), was significantly associated with the presence of two or more DAIA symptoms in the bipolar sample and three or four DAIA symptoms in the unipolar sample.

CONCLUSION

DAIA symptoms were associated with greater severity of manic symptoms in mixed depression. DAIA symptoms must be evaluated in all patients with mixed features and are associated with the severity of depressive and manic symptoms in mixed depression.

Treatment of mixed depression with theta-burst stimulation (TBS): results from a double-blind, randomized, sham-controlled clinical trial

Mixed depression is probably different in terms of clinical course and response to treatment. Repetitive transcranial magnetic stimulation (rTMS) is well established in non-mixed depression, and theta-burst stimulation (TBS) protocol is replacing conventional protocols because of noninferiority and reduced delivery time. However, TBS has not been adequately studied in mixed states. This study was a double-blind, six-week, sham-controlled, and randomized clinical trial of bilateral TBS targeting the right and left dorsolateral prefrontal cortex, respectively. Adults with bipolar and major depressive disorder experiencing an acute mixed depression were eligible if they had not benefited from a first- or second-line treatment for acute unipolar or bipolar depression recommended by the Canadian Network for Mood and Anxiety Treatments. Out of 100 patients included, 90 composed modified intention-to-treat sample, which was patients that completed at least one week of the intervention. There were no significant differences in Montgomery-Asberg depression rating scale score changes (least squares mean difference between groups at week 3, -0.06 [95% CI, - 3.39 to 3.51; P = 0.97] in favor of sham TBS). Response and remission rates per MADRS were also not statistically different among active and sham groups (35.7% vs. 43.7%, and 28.5% vs. 37.5% respectively at week 6, ps > 0.51). No other analyses from baseline to weeks 3 or 6 revealed significant time x group interaction or mean differences among groups in the mITT sample. Bilateral TBS targeting the DLPFC is not efficacious as an add-on treatment of acute bipolar and unipolar mixed depression. ClinicalTrials.govIdentifier: NCT04123301.