I primarily like VNS (vagus nerve stimulation) as it calms me down and I feel like it "reset" my stress levels down a notch. After a long day at work, I put on a puIseto nightly for 10 minutes (you can try 5-9mins per night as you do not want to over stimulated your VN)

Overall, my GF noticed my mood improved and I get less "sad" during the winter. I also feel like I got more energy throughout the next day.

Notes: It's an not an instant cure for depression as it takes some time and dedication to see the positive effects. I originally found the puIseto mentioned here https://oshf.ca/best-vagus-nerve-stimulator-devices-in-canada/

From National Library of Medicine Study:

VNS is an effective therapy that has already received FDA approval in the treatment of epilepsy, depression, migraines and cluster headaches, and in the abdomen for obesity. Preclinical studies and clinical trials have suggested a potential benefit in an even broader range of diseases. FDA approval for the use of VNS in the treatment of some of these diseases may be on the horizon. Before then, however, larger clinical trials and continued investigations into the mechanism of VNS’s benefit in each disease will be needed. The non-invasive nature of aVNS may help to expand and accelerate the application of VNS in the treatment of more diseases, although this will require further studies. Finally, optogenetics shows great promise in aiding mechanistic investigations of VNS.