Predictors of efficacy and utility of home-based transcranial Direct Current Stimulation treatment (tDCS) for depressive disorder : A retrospective and naturalistic study
Zhang, Inni (2024-04-29)
Predictors of efficacy and utility of home-based transcranial Direct Current Stimulation treatment (tDCS) for depressive disorder : A retrospective and naturalistic study
(29.04.2024)
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty.
suljettu
Julkaisun pysyvä osoite on:
https://urn.fi/URN:NBN:fi-fe2024050326314
https://urn.fi/URN:NBN:fi-fe2024050326314
Tiivistelmä
Objectives: Major depressive disorder (MDD) is the most important cause of work disability in Finland. Transcranial Direct Current Stimulation (tDCS) is a promising adjuvant treatment option which can be used together with psychotherapy, pharmacotherapy, or both. Outcomes in randomized controlled trials of tDCS are heterogeneous due to different methodologies and protocols. This retrospective observational psychiatric study aims to investigate the efficacy of tDCS on depression in a home-based manner and identify the predictor variables that affect the outcomes. Our research targeted patients with unipolar depressive disorder who were registered at the Turku University Hospital (TUH) psychiatric neuromodulation unit between the years 2017 and 2023.
Methods: 114 patients met the criteria of our study. 55 male and 59 female, with a mean age of 38.25 (SD=13.75) and a mean education duration of 13.71 years (SD=2.83). Anxiety disorder and personality disorders were the most common comorbid mental conditions. Patients were assessed using Montgomery-Åsberg Depression Rating scale (MÅDRS) and Beck Depression Inventory (BDI-21) at the beginning, in the 6th week, and every 6 months until treatment completion. The stimulation protocol was standardized, employing bifrontal electrode placement with anode over the left dorsolateral prefrontal cortex (F3) and cathode over the right dorsolateral prefrontal cortex (F4). Stimulation intensity was set to 2 mA with a session duration of 30 minutes. Patients received daily tDCS treatment for at least six weeks, initially supervised by a trained psychiatric nurse at the unit, and later self-administered at home.
We collected diverse variables including sociodemographic information (age, education, gender, etc.), clinical characteristics (age of onset of the first depressive episode, the duration of the current episode, etc.), medications, and psychiatric comorbidities. Both univariate and multivariate analyses were performed, and the effect sizes of significant variables were calculated. All analyses were conducted using R software (version 4.3.3). In this study, remitters were patients with MÅDRS scores ≤ 10, and responders were those with a >50% reduction in their MÅDRS score from baseline or who achieved remission with a <50% change in MADRS score.
Results: The rate of treatment-resistant depression (TRD) in this cohort was 87.7%. It was observed that there was a significant improvement in the severity of depression, with a mean improvement of 22.4%. The response and remission rates (16.7% and 14%, respectively) in the 6th week aligned with findings from previous studies. Additionally, improvement continued to increase over time for patients who continued treatment beyond the 6th week (24.6% and 21.1%).
After conducting both uni- and multivariate analyses, education was identified as the most significant single factor positively relating to treatment outcomes (β=-0.29, p=0.018), while age was found to be the most significant factor negatively associated with tDCS efficacy (β=0.38, p=0.012). Higher baseline MÅDRS scores were positively related to tDCS outcomes, whereas higher baseline BDI-21 scores were negatively related. Longer treatment duration was associated with higher treatment outcomes at the endpoint. Contrary to previous studies' hypotheses, no associations were found between personality disorders, SSRI usage, alcohol consumption, benzodiazepine usage and tDCS efficacy.
Conclusions: Our study findings indicate that patients with MDD, including those with TRD, may benefit from tDCS treatment, although we cannot assess the placebo effect in retrospective observational research. Additionally, patients may benefit from longer treatment course durations. Age was found to have a negative association to tDCS efficacy, while education is positively related to tDCS outcomes. Furthermore, higher depression baseline severity did not reduce the effectiveness of tDCS treatment.
Methods: 114 patients met the criteria of our study. 55 male and 59 female, with a mean age of 38.25 (SD=13.75) and a mean education duration of 13.71 years (SD=2.83). Anxiety disorder and personality disorders were the most common comorbid mental conditions. Patients were assessed using Montgomery-Åsberg Depression Rating scale (MÅDRS) and Beck Depression Inventory (BDI-21) at the beginning, in the 6th week, and every 6 months until treatment completion. The stimulation protocol was standardized, employing bifrontal electrode placement with anode over the left dorsolateral prefrontal cortex (F3) and cathode over the right dorsolateral prefrontal cortex (F4). Stimulation intensity was set to 2 mA with a session duration of 30 minutes. Patients received daily tDCS treatment for at least six weeks, initially supervised by a trained psychiatric nurse at the unit, and later self-administered at home.
We collected diverse variables including sociodemographic information (age, education, gender, etc.), clinical characteristics (age of onset of the first depressive episode, the duration of the current episode, etc.), medications, and psychiatric comorbidities. Both univariate and multivariate analyses were performed, and the effect sizes of significant variables were calculated. All analyses were conducted using R software (version 4.3.3). In this study, remitters were patients with MÅDRS scores ≤ 10, and responders were those with a >50% reduction in their MÅDRS score from baseline or who achieved remission with a <50% change in MADRS score.
Results: The rate of treatment-resistant depression (TRD) in this cohort was 87.7%. It was observed that there was a significant improvement in the severity of depression, with a mean improvement of 22.4%. The response and remission rates (16.7% and 14%, respectively) in the 6th week aligned with findings from previous studies. Additionally, improvement continued to increase over time for patients who continued treatment beyond the 6th week (24.6% and 21.1%).
After conducting both uni- and multivariate analyses, education was identified as the most significant single factor positively relating to treatment outcomes (β=-0.29, p=0.018), while age was found to be the most significant factor negatively associated with tDCS efficacy (β=0.38, p=0.012). Higher baseline MÅDRS scores were positively related to tDCS outcomes, whereas higher baseline BDI-21 scores were negatively related. Longer treatment duration was associated with higher treatment outcomes at the endpoint. Contrary to previous studies' hypotheses, no associations were found between personality disorders, SSRI usage, alcohol consumption, benzodiazepine usage and tDCS efficacy.
Conclusions: Our study findings indicate that patients with MDD, including those with TRD, may benefit from tDCS treatment, although we cannot assess the placebo effect in retrospective observational research. Additionally, patients may benefit from longer treatment course durations. Age was found to have a negative association to tDCS efficacy, while education is positively related to tDCS outcomes. Furthermore, higher depression baseline severity did not reduce the effectiveness of tDCS treatment.