Aim 9.1.1: To determine the effect of ibogaine treatment on whole-brain spectral band power (delta 1-4Hz, theta 4-8Hz, alpha 8-13Hz, beta 13-30Hz, and gamma 30-50Hz frequency bands) as measured by resting-state EEG changes from baseline to immediate and one month post-treatment in an observational study of individuals with history of TBI. - Gonzalez et al. 2021 - https://doi.org/10.1021/acsptsci.0c00164 Intracranial EEG evidence in rodents of the acute effects of ibogaine on band power. Found increased theta and gamma power. - Binienda et al. 1998 - https://doi.org/10.1111/j.1749-6632.1998.tb08241.x Found delta, theta, alpha and beta band power decreased immediately after ibogaine exposure in anesthetized rats. This extended in time in delta only. Aim 9.1.2: To determine the effect of ibogaine treatment on spectral band power (delta 1-4Hz, theta 4-8Hz, alpha 8-13Hz, beta 13-30Hz, and gamma 30-50Hz frequency bands) in hub regions of the default mode network and other implicated functional brain networks as measured by resting-state EEG changes from baseline to immediate and one month post-treatment in an observational study of individuals with history of TBI. - Multiple studies of other psychedelic drugs have shown reductions in broadband power in default mode network hubs, especially of lower frequencies, following acute psychedelic use (LSD, Psilocybin, Ayahuasca, DMT). Aim 9.2: To determine whether observed changes in spectral band power correlate with changes in clinical symptoms from baseline to immediate post treatment in an observational study of individuals with a history of TBI. - TBI is associated with diffuse slowing (increased power of slow frequencies). We therefore might expect oscillatory power to normalize with the resolution of TBI-linked psychopathologies. Aim 9.3: To determine whether observed changes in spectral band power correlate with changes in cognitive function from baseline to immediate post treatment in an observational study of individuals with a history of TBI. - Decreases in oscillatory power at lower frequencies have been associated with greater neural function.