Treatment effect variability in brain stimulation across psychiatric disorders: A meta-analysis of variance. (May 2021)

• Record Type: Journal Article
• Authors: Homan, Stephanie; Muscat, Whitney; Joanlanne, Andrea; Marousis, Nikolaos; Cecere, Giacomo; Hofmann, Lena; Ji, Ellen; Neumeier, Maria; Vetter, Stefan; Seifritz, Erich; Dierks, Thomas; Homan, Philipp
• Is Part Of: Neuroscience and biobehavioral reviews. Volume 124(2021)
• Page Start: 54
• Page End: 62
• Publication Date: 2021-05
• Subjects: Heterogeneity in treatment response -- Noninvasive brain stimulation -- Transcranial magnetic stimulation -- Transcranial direct current stimulation -- Personalized treatment -- Unipolar and bipolar depression -- Schizophrenia spectrum disorder -- Bipolar disorder -- Obsessive–compulsive disorder; Psychophysiology -- Periodicals; Human behavior -- Periodicals; Animal behavior -- Periodicals; Neurology -- Periodicals; Behavior -- Periodicals; Ethology -- Periodicals; Neurology -- Periodicals; Psychophysiologie -- Périodiques; Comportement humain -- Périodiques; Animaux -- Mœurs et comportement -- Périodiques; Neurologie -- Périodiques; Animal behavior; Human behavior; Neurology; Psychophysiology; Periodicals; Electronic journals; 573.8
• DOI: 10.1016/j.neubiorev.2020.11.033
• Languages: English
• ISSNs: 0149-7634

Abstract

Highlights: The potential for precision medicine in brain stimulation is unclear. To evaluate the need, variability between active and sham conditions can be compared. Greater variability would indicate a need for precision medicine. Variability was only slightly increased for active compared with sham across modalities. This increase was mostly driven by studies in schizophrenia. Abstract: Noninvasive brain stimulation methods such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are promising add-on treatments for a number of psychiatric conditions. Yet, some of the initial excitement is wearing off. Randomized controlled trials (RCT) have found inconsistent results. This inconsistency is suspected to be the consequence of variation in treatment effects and solvable by identifying responders in RCTs and individualizing treatment. However, is there enough evidence from RCTs that patients respond differently to treatment? This question can be addressed by comparing the variability in the active stimulation group with the variability in the sham group. We searched MEDLINE/PubMed and included all double-blinded, sham-controlled RCTs and crossover trials that used TMS or tDCS in adults with a unipolar or bipolar depression, bipolar disorder, schizophrenia spectrum disorder, or obsessive compulsive disorder. In accordance with the PRISMA guidelines to ensure data quality and validity, we extracted a measure of variability of the primary outcome. A total of 130 studies with 5748 patients were considered in the analysis. We calculated variance-weighted variability ratios for each comparison of active stimulation vs sham and entered them into a random-effects model. We hypothesized that treatment effect variability in TMS or tDCS would be reflected by increased variability after active compared with sham stimulation, or in other words, a variability ratio greater than one. Across diagnoses, we found only a minimal increase in variability after active stimulation compared with sham that did not reach statistical significance (variability ratio = 1.03; 95% CI, 0.97, 1.08, P = 0.358). In conclusion, this study found little evidence for treatment effect variability in brain stimulation, suggesting that the need for personalized or stratified medicine is still an open question.