Major depression is common in people over the age of 50, particularly in those at socioeconomic disadvantage, or with poor physical health and previous depressive symptoms.

Assessment: People with major depression were identified using the short form of the Composite International Diagnostic Interview. Diagnosis of depression required five or more depressive symptoms in the same two week period during the year preceding the interview. The short form of the Center for Epidemiological Studies Depression scale was used to assess the severity of depressive symptoms occurring in the week preceding the interview. People were defined as having persistent significant depressive symptoms if they had significant depressive symptoms at all assessments. Most interviews were conducted by telephone. Twelve month prevalence and variables associated with major depression and persistence were assessed using multivariate logistic regression and contingency tables.