Electroencephalogram (EEG) has long been used to examine individual differences in brain function and neuropsychiatric health (Smit et al., 2021). EEG coherence (EEGc) is a heritable measure of neural functional connectivity, which measures the degree of synchrony in brain oscillatory activity between two regions (Chorlian, Rangaswamy, & Porjesz, 2009; Chorlian et al., 2007; Markovska-Simoska, Pop-Jordanova, & Pop-Jordanov, 2018). The human central nervous system has a prolonged developmental course, with critical periods in early life and adolescence, especially in prefrontal regions (Larsen & Luna, 2018; Silbereis, Pochareddy, Zhu, Li, & Sestan, 2016). Childhood stress can harm neural development during these sensitive periods (Andersen et al., 2008). Increased neural functional connectivity, measured via EEG, has been observed in cross-sectional studies of childhood trauma (Cook, Ciorciari, Varker, & Devilly, 2009), and adults with AUD and PTSD (Almli et al., 2018; Dunkley et al., 2015; Huang, Mohan, De Ridder, Sunaert, & Vanneste, 2018; Park et al., 2017), suggesting that increased functional connectivity may be a shared pathway of risk for AUD and PTSD. Associations between EEGc and neuropsychiatric conditions are complex, but better characterized
