This study consists of two parts:~CLINICAL TRIAL PART: This part will be conducted in depressed and age- and sex-matched healthy participants. It has a double-blind, randomized crossover design. Each participant will undergo 1 week of baseline monitoring, followed by 1 week of in-home stimulation and 1 week of placebo condition interleaved with 1 week wash-out period. The last night of each intervention week will take place in a laboratory setting. A final week of follow-up will follow the second intervention week.~The following data is collected:~Single-channel EEG (at home) and high-density electroencephalogram (hdEEG) (in laboratory)~MR imaging~Daily questionnaires~Passive behavioural and physiological measurements~MONITORING PART: This observational study part will be conducted in depressed participants only. Each participant will undergo 5 weeks of remote monitoring using wearable devices and smartphones. Patients not eligible for the CLINICAL TRIAL PART, or that meet an exclusion criterion at any point in the study, can be assigned to this study part.
The goal of this clinical trial is to learn about the effects of phase-targeted auditory stimulation in depressed patients and healthy controls.~The main questions it aims to answer are:~Is auditory down-phase stimulation efficient in improving depression symptoms as compared to sham stimulation?~Can mood and other outcomes be prospectively estimated by multi-parametric passive data?~Participants will perform auditory stimulation using a wearable device at home and provide data on their phone usage and activity.~Researchers will compare depressed patients and healthy participants to see if auditory down-phase stimulation effects them differently.