Clinical effects and correlates of standard rTMS and theta burst stimulation (TBS) on suicidal ideation in late-life depression

TL;DR

This study examines how rTMS and TBS affect suicidal thoughts in older adults with depression, finding both treatments effective with possible sex differences in TBS outcomes.

Contribution

The study provides new insights into the effectiveness of rTMS and TBS for reducing suicidal ideation in late-life depression, including potential sex-based differences in TBS response.

Findings

Both standard rTMS and TBS significantly reduced suicidal ideation in late-life depression.

Females showed higher remission rates with TBS compared to males.

Improvement in cognitive flexibility and inhibition correlated with reduced suicidal ideation.

Abstract

Previous studies have shown that repetitive transcranial magnetic stimulation (rTMS) can treat suicidal symptoms; however, the effects of rTMS on suicidal ideation (SI) in late-life depression (LLD) have not been well-characterized, particularly with theta burst stimulation (TBS).

Data were analyzed from 84 older adults with depression from the FOUR-D trial (ClinicalTrials.gov identifier: NCT02998580), who received either bilateral standard rTMS or bilateral TBS targeting the dorsolateral prefrontal cortex. The primary outcome was change in the Beck Scale for Suicide Ideation (SSI). The secondary outcome was remission of SI. Demographic, cognitive, and clinical characteristics that may moderate the effects of rTMS or TBS on SI were explored.

There was a statistically significant change in the total SSI score over time [χ2(7) = 136.018, p < 0.001], with no difference between the two treatment groups. Remission of SI was 55.8% in the standard rTMS group and 53.7% in the TBS group. In the standard rTMS group, there was no difference in remission of SI between males and females, whereas remission was higher in females in the TBS group (χ2(1) =6.87, p = 0.009). There was a significant correlation between time to remission of SI and RCI z-score for D-KEFS inhibition/switching [rs = −0.389, p = 0.012].

Both bilateral rTMS and bilateral TBS were effective in reducing SI in LLD. There may be sex differences in response to TBS, with females having more favorable response in reducing SI. There may be an association between improvement in cognitive flexibility and inhibition and reduction of SI.

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