LAUSR

The field of noninvasive brain stimulation (NIBS) including transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) and transcranial magnetic stimulation (TMS) has been growing exponentially since the last decade of the 20th century (Krishnan et al., 2015; Meeker et al., 2020). This is because NIBS has enabled us to move from the correlational studies performed using electroencephalography (EEG), magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI) or near-infrared spectroscopy (NIRS) to causational studies, where we can directly observe the effects of stimulation on a specific part of the brain (especially in the case of TMS; Farzan et al., 2016). By using NIBS, we can investigate neuroplasticity, cerebral connectivity, and cortical excitability (Di Lazzaro et al., 2018; Reinhart et al., 2017). On the other side, we got a powerful new tool for the treatment of different neurophysiological disorders—from 2008 the Food and Drug Administration (FDA) in the United States certified five TMS devices for treatment of drug-resistant major depressive disorder and protocols are being developed for the treatment of addiction (Yavari et al., 2016), chronic pain (Cardenas-Rojas et al., 2020), stroke (Ovadia-Caro et al., 2019), epilepsy (Kim et al., 2020), obsessive–compulsive disorder (Grover et al., 2021) and schizophrenia (Osoegawa et al., 2018). Special emphasis in these researches is placed on neurodegenerative diseases like Parkinson’s disease (Madrid & Benninger, 2021) and Alzheimer’s disease (Buss et al., 2019) considering that dementia is ranked as the seventh leading cause of death in the world with no known cure or effective way to stop the progression (World Health Organization, 2019). However, despite all these potentials, the high variability in the results of NIBS studies lead some scientist to ask a very valid question “Is There a Future for Non-invasive Brain Stimulation as a Therapeutic Tool?” (Terranova et al., 2018). And their answer is “Yes” if we find a way to personalize it. A very effective way to do that would be through usage of biomarkers (like gene polymorphisms) and this is where the paper by Pellegrini et al. (2021a) attempts to give its contribution. In their recent paper, Pellegrini et al. tried to determine if the interindividual variability to tDCS was in part genetically mediated. To address this issue, they performed the following experiment—in a group of healthy males, they used anodal bicephalic tDCS montage (the active