The blog Neuroskeptic discusses new research suggesting that how we perceive the emotional lives of others significantly affects how depressed or anxious we feel. From the post:
In the first experiment, the authors quizzed people how many days per month they felt “depressed, sad, blue, tearful” or had “excessive anxiety about a number of events or activities.” They then asked them a series of questions designed to work out how they thought other people would answer than question. So they could work out where each individual thought they ranked within the general population, in terms of depression or anxiety symptoms.
Take a look. The top panel shows someone who felt depressed on 5 days a month, but believed this put him in the most depressed 70% of people. The second person felt depressed twice as often, but she thought she was below average.
They found that perceived rank was strongly correlated with whether people thought they "had depression" or "had anxiety" - much more strongly than actual frequency of symptoms. "Having depression" meant "being more depressed than other people".
Read the entire post at Neuroskeptic.