FELIX is a clinical research protocol investigating whether non-invasive 40 Hz gamma neurostimulation delivered through light can reduce depressive symptoms. The study is motivated by the need for novel and scalable treatment options for depression, where a substantial proportion of patients do not achieve sufficient benefit from existing interventions.
The project was developed within Horizon Europe's Marie Skłodowska-Curie Actions programme under the Astrotech consortium, a multidisciplinary research and training network comprising 15 early-stage researchers across host institutions and projects spanning astrocyte biology, neurotechnology, and light-based stimulation. Building on a growing preclinical and translational evidence base linking 40 Hz sensory stimulation to neurobiological effects — including enhanced gamma-band oscillatory activity, glymphatic clearance, and neuroimmune modulation — FELIX constitutes a significant part of the early efforts to systematically evaluate this intervention in a psychiatric population. The study aims not only to assess clinical efficacy, but to contribute mechanistic insight into the neurophysiological processes engaged by gamma-frequency entrainment in the context of major depressive disorder.
The study is conducted as a randomized, double-blinded, placebo-controlled trial at Psychiatric Centre Copenhagen in collaboration with the Technical University of Denmark and OptoCeutics ApS, developer of the patented Invisible Spectral Flicker technology. By evaluating a home-based, non-invasive intervention, FELIX examines whether this approach may be practical and potentially scalable as an adjunct to existing depression treatment.