The current study describes results from the EEG workgroup of the ENIGMA consortium (Thompson et al., 2014; Thompson et al., 2017). We developed EEG processing protocols to extract common measures for band power in standard frequency bands: delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz) and beta (13–30 Hz) power at the vertex (Cz) electrode, and occipital (O1, O2) alpha power and alpha peak frequency consistent with (Malone et al., 2014). GWAS results of three population‐based twin and two (alcohol‐dependence) ascertained family cohorts from the Netherlands, Australia, and US were combined in a meta‐analysis for a total of 8,425 individuals (see also Thompson et al., 2017). The combined meta‐analyzed results were subsequently entered into the post‐GWAS pipeline of analyses. Given the importance of oscillatory activity in neural communication and the large body of literature on deviant oscillatory activity in psychiatric traits, we expect that genes identified in this study will also affect neuropsychiatric and behavioral phenotypes. The subsequent expression analyses will indicate via which pathways these genes may influence brain expression, and in turn, EEG oscillations.
