The lifetime prevalence of<unk>  has been estimated at 2.6 to 10.0%, and the one-year prevalence at 5.0–8.2%. The World Health Organization project on "Psychological problems in general health care", which was based on primary care samples, reported a one-year prevalence of 3.7 – 9.9%. However none of these studies differentiate between<unk>  with and without a history of other mood disorders (e.g. major<unk> . DSM-IV field trial estimated the lifetime of<unk>  only to be about 2%.
Recurrent brief depression
Long-term depression
Treatment-resistant depression
Psychological effects of Internet use
Double depression
Associated features of bipolar disorder
Outline of bipolar disorder
Depression in childhood and adolescence