A low-voltage alpha (LVA) phenotype, characterized by an absence or very low-amplitude alpha rhythmicity, is found in 5–10% of individuals (Anokhin et al., 1992; Enoch et al., 1995). The exon 7 variant of the GABAB receptor gene and EEG alpha voltage (LVA or normal) was significantly associated for control but not alcoholic subjects (Winterer et al., 2003b). LVA in females has been associated with a genetic variant resulting in low catechol-O-methyltransferase activity, which is involved in the dopaminergic system, yielding low levels of norepinephrine (Enoch et al., 2003). This may partly explain the association of LVA and anxiety disorders in alcoholic women.
