Prognostic factors in major depressive disorder: comparing responders and non-responders to Repetitive Transcranial Magnetic Stimulation (rTMS), a naturalistic retrospective chart review

Older age associated with better antidepressant response to H1-coil transcranial magnetic stimulation in female patients

BACKGROUND

TMS is increasingly used to treat depression, but predictors of treatment outcomes remain unclear. We assessed the association between age and TMS response given inconsistent prior reports limited by small sample size, heterogeneity, outdated TMS parameters, lack of assessment of H1-coil TMS, and lack of an a priori hypothesis. We hypothesized that older age would be associated with better treatment response based on trends in recent large exploratory analyses.

METHODS

We conducted a naturalistic retrospective analysis of patients (n = 378) ages 18-80 with depression (baseline Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) > 5) who received 29-35 sessions of TMS between 2014 and 2021. Response was assessed using percent reduction of QIDS-SR. The relationship between percent response or remission and age group was assessed using the chi-square test.

RESULTS

85 % of patients received the standard protocol of H1-coil TMS to the left DLPFC. Percent response and remission rates for the entire study sample increased with age (response: p = .026; remission: p = .0023). This finding was stronger in female patients (response: p = .0033; remission: p = .00098) and was not observed in male patients (response: p = .73; remission: p = .26). This was confirmed in a sub-analysis of patients who only received the standard protocol with the H1-coil for the entire treatment course.

LIMITATIONS

Naturalistic retrospective analysis from one academic center.

CONCLUSIONS

Older age is associated with a better antidepressant response to H1-coil TMS in female patients. This was demonstrated in a hypothesis-driven confirmation of prior exploratory findings in a large sample size with a homogeneous data collection protocol across all participants.

Predictors of remission after repetitive transcranial magnetic stimulation for the treatment of late-life depression

Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment in patients with depression, yet treatment response remains variable. While previous work has identified predictors of remission in younger adults, relatively little data exists in late-life depression (LLD). To address this gap, data from 164 participants with LLD from a randomized non-inferiority treatment trial comparing standard bilateral rTMS to bilateral theta burst stimulation (TBS) (ClinicalTrials.gov identifier: NCT02998580) were analyzed using binary logistic regression and conditional inference tree (CIT) modeling. Lower baseline depression symptom severity, fewer prior antidepressant treatment failures, and higher global cognition predicted remission following rTMS treatment. The CIT predicted a higher likelihood of achieving remission for patients with a total score of 19 or lower on the Montgomery-Åsberg Depression Rating Scale, 1 or fewer prior antidepressant treatment failures, and a total score of 23 or higher on the Montreal Cognitive Assessment. Our results indicate that older adults with lower severity of depression, fewer antidepressant treatment failures, and higher global cognition benefit more from current forms of rTMS. The results suggest that there is potentially higher value in using rTMS earlier in the treatment pathway for depression in older adults.

Accelerated TMS - moving quickly into the future of depression treatment

Accelerated TMS is an emerging application of Transcranial Magnetic Stimulation (TMS) aimed to reduce treatment length and improve response time. Extant literature generally shows similar efficacy and safety profiles compared to the FDA-cleared protocols for TMS to treat major depressive disorder (MDD), yet accelerated TMS research remains at a very early stage in development. The few applied protocols have not been standardized and vary significantly across a set of core elements. In this review, we consider nine elements that include treatment parameters (i.e., frequency and inter-stimulation interval), cumulative exposure (i.e., number of treatment days, sessions per day, and pulses per session), individualized parameters (i.e., treatment target and dose), and brain state (i.e., context and concurrent treatments). Precisely which of these elements is critical and what parameters are most optimal for the treatment of MDD remains unclear. Other important considerations for accelerated TMS include durability of effect, safety profiles as doses increase over time, the possibility and advantage of individualized functional neuronavigation, use of biological readouts, and accessibility for patients most in need of the treatment. Overall, accelerated TMS appears to hold promise to reduce treatment time and achieve rapid reduction in depressive symptoms, but at this time significant work remains to be done. Rigorous clinical trials combining clinical outcomes and neuroscientific measures such as electroencephalogram, magnetic resonance imaging and e-field modeling are needed to define the future of accelerated TMS for MDD.

Managing substance use in patients receiving therapeutic repetitive transcranial magnetic stimulation: A scoping review

Repetitive Transcranial Magnetic Stimulation (rTMS) is an invaluable treatment option for neuropsychiatric disorders. Co-occurring recreational and nonmedical substance use can be common in those presenting for rTMS treatment, and it is unknown how it may affect the safety and efficacy of rTMS for the treatment of currently approved neuropsychiatric indications. This scoping review aimed to map the literature on humans receiving rTMS and had a history of any type of substance use. The search identified 274 articles providing information on inclusion/exclusion criteria, withdrawal criteria, safety protocols, type of rTMS and treatment parameters, adverse events and effect on primary outcomes that related to substance use. There are neurophysiological effects of substance use on cortical excitability, although the relevance to clinical rTMS practice is unknown. The current literature supports the safety and feasibility of delivering rTMS to those who have co-occurring neuropsychiatric disorder and substance use. However, specific details on how varying degrees of substance use alters the safety, efficacy, and mechanisms of rTMS remains poorly described.