People who ate breakfast once a week or less had nearly three times the odds of developing depression symptoms over three years, compared with people who ate it every day. A study of 716 workers in Japan found the risk climbed as breakfast got rarer. At a Japanese electrical manufacturer, 716 employees aged 19 to 68 answered detailed questions about what and how often they ate. None of them had depression symptoms or a mental health diagnosis at the start. Three years later, researchers from Japan's National Center for Global Health and Medicine checked who had developed symptoms using a standard depression questionnaire. The study appeared in Psychiatry Research in 2019. Breakfast frequency was sorted into five groups: daily, 5 to 6 times a week, 3 to 4 times, 1 to 2 times, and once a week or less. People in the rarest group had 2.9 times the odds of developing depression symptoms, even after accounting for the rest of their diet and their lifestyle. The odds tended to rise with each step down in breakfast frequency. Low mood can make people skip meals, which raises a chicken-and-egg question. Starting with people who had no depression symptoms helps with that, although it can't settle it completely, and every participant worked for the same company in one country. Among these 716 employees, the ones who almost never ate breakfast were the likeliest to develop depression symptoms three years later.