Abstract

Posterior EEG alpha quantified by reference-free CSD-fPCA is linked to positive outcome following treatment for depression with serotonin reuptake inhibitors (Tenke et al., Biological Psychiatry, 70(4):388-394, 2011). Posterior alpha has also been linked to depression, and may persist following successful treatment. However, it is not known whether depressed individuals with positive outcomes following other treatments, or with spontaneous remissions, differ in posterior alpha. Inasmuch as religious concordance across generations is associated with reduced depression risk, posterior EEG alpha might also differ between individuals who regard religion as highly important and those who do not. Resting 13-channel EEG (eyes closed/open; 200 sps) was recorded from 52 participants in a longitudinal study of familial risk for depression. Self-reported importance of religion or spirituality was classified as important or not ("Highly Important" vs. all other responses on a 4-point scale) at the time of the EEG recording and at an assessment 10 y earlier. Consistent with previous findings, CSD-fPCA yielded three alpha components (8-12 Hz loadings peaks), two of which had topographic maxima at posterior sites for eyes closed. Twelve participants who rated their religion or spirituality as highly important at the initial assessment showed significantly greater medial-posterior CSD alpha when compared to 40 rated as not important (t = 3.9, df = 50, p < .001). In contrast, alpha did not differ between 20 rated as important and 32 rated not important at the second (concurrent) assessment. The relationship between the changing importance and alpha was clarified by comparing those who rated religion highly important at initial assessment and those for whom religion became important later (12 migrators). Migrators failed to show enhanced alpha, but instead showed significantly less alpha than those rated important in the initial assessment. Those who never rated religion important (n = 28) did not differ from either important group, although their median alpha provided a robust classification criterion that distinguished between the two important groups (Fisher Exact, p < .005). The difference between the two important groups was evident for analyses restricted to participants with a history of depression, but not those with no depression history. These results extend the view of posterior EEG alpha beyond that of a persistent, transgenerational marker for depression and treatment outcome, suggesting that lifetime depression can itself reveal an underlying association between the prominence of EEG alpha and the persistence or later development of personal religious belief. Supported by NIMH grants MH36197 and MH36295 and the John Templeton Foundation.