Some diseases are contagious–like colds, flu, and chicken pox. But what about loneliness? Loneliness may not be a disease, at least not in the same way that chicken pox is. But loneliness can be contagious. How so? The same way that many emotions can be infectious. Being around someone who’s really happy can put you in a good mood. While hanging around someone who’s depressed can be, well, depressing. The same goes for loneliness. According to one study, the average person feels lonely about forty-eight days per year. Having a lonely friend adds around seventeen extra days of lonely feelings.