Sleep may be the key to better mental health according to a recent study from South Korea.
Researchers at the Workplace Mental Health Institute at the Kangbuk Samsung Medical Center studied over 200,000 workers, aged between 20 and 40 years, who had visited the medical center for check-ups in 2014.
Shin Young-chul, the head of the institute, and his team found that among those who slept just four hours a day, the pervasiveness of depression was…