Depressive disorders are the most common diagnosis among individuals who die by suicide, and intermittent theta-burst stimulation (iTBS) is a noninvasive treatment for those with difficult-to-treat depression who are at higher risk for suicide. Previous data suggests that pairing iTBS with D-cycloserine, a partial N-methyl-D-aspartate (NMDA) receptor agonist, improves antidepressant outcomes. However, its impact on suicide risk is not known.

We examine suicidal ideation and implicit suicide risk after iTBS+D-cycloserine in two clinical trials (open-label trial [n = 12] and randomized placebo-controlled trial [RCT, n = 50]) involving adults with major depressive disorder and the acute effects of D-cycloserine on implicit suicide risk in a crossover trial (n = 18). Implicit suicide risk was assessed using the computerized death/suicide implicit association test (IAT), and depressive symptoms and suicidal ideation were assessed using the clinician-rated Montgomery–Asberg Depression Rating Scale (MADRS).

Open-label iTBS+D-cycloserine was associated with a rapid reduction in suicidal ideation, and iTBS+D-cycloserine was superior to iTBS+placebo in reducing suicidal ideation. Similarly, open-label iTBS+D-cycloserine was associated with decreased implicit suicide risk as measured by the death/suicide IAT, and iTBS+D-cycloserine was associated with greater decreases in death/suicide IAT scores compared to iTBS+placebo. A single acute dose of D-cycloserine in the absence of iTBS had no effect on implicit suicide risk.

Adjunctive D-cycloserine with iTBS is a promising strategy to reduce suicidal ideation and implicit suicide risk in depression.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulatory treatment option, which is used in a variety of neurological and psychiatric diseases. It is approved for depression treatment and recommended in international guidelines. A significant reduction in treatment duration was achieved by using theta burst stimulation (TBS) protocols, which are practicable and non-inferior to conventional TMS.

To analyse the efficacy and safety of intermittent theta burst stimulation (iTBS) of left DLPFC in inpatients with treatment-resistant depression.

We evaluated n=44 inpatients with treatment resistant major depressive disorder (n=37) and bipolar depression (n=7), who were treated with the 5 Hz intermittent TBS once daily for 3-6 weeks according to clinical decision. A total of 600 pulses and 200 bursts were applied in each treatment session. Clinical and response data were obtained by chart review.

Mean age at time of first stimulation was 54 years. 61,3 % of patients were female. On average, the current episode started 21 months before the first stimulation. In total, 924 treatment sessions were performed. On average, patients received 21 sessions. The mean MADRS Score pre-treatment was 27.2. Post-treatment, there was a clear reduction in depression severity (MADRS 18.3). No severe adverse events and no seizures occurred in this clinical observational analysis.

Intermittent TBS is efficacious and safe in patients with chronic and refractory depression.

No significant relationships.