At-home limbic-targeted transcranial electrical stimulation during sleep: a feasibility study in healthy adults

Deep sleep (N3) and rapid eye movement (REM) sleep are critical for memory and emotional regulation and are often disrupted in neurological and psychiatric disorders. Recent work suggests that focal limbic slow oscillations may provide a target for transcranial electrical stimulation (TES). This study evaluated the feasibility of low-intensity, limbic-targeted TES during sleep and its effects on sleep architecture in healthy adults. A total of 17 healthy participants completed a sham-controlled intervention using an at-home TES device. Stimulation was synchronized with N2 onset, and an overnight electroencephalogram (EEG) was recorded. Sleep stage durations and proportions were compared between TES and off conditions. Limbic-targeted TES was associated with longer total sleep time than the off condition. A repeated-measures ANOVA demonstrated a significant main effect of condition without a significant condition × sleep-stage interaction. Planned pairwise comparisons showed longer absolute N3 and REM sleep durations during TES, whereas only REM increased as a proportion of total sleep time. Participants tolerated the device well, and blinding was maintained. Limbic-targeted TES was feasible to administer during sleep in a natural home environment and was associated with increased total sleep time. These findings provide preliminary evidence of sleep-architecture modulation and support further investigation in larger studies and clinical populations. This article is part of the discussion meeting issue 'Digital healthcare for the management of functional neurological disorders'.