The Newcastle Chronic Depression Study. Patient characteristics and factors associated with chronicity.

Chronic depression is defined as "symptomatic non-recovery for a period of 2 or more years". Chronic primary major depressives (n = 24) were compared retrospectively with a control group of primary major depressives (n = 20) who had recovered from their illness episode within 2 years. The former had a significantly higher familial loading for affective disorder and showed an increased incidence of independent undesirable life events during the 6 months prior to and 2 years after the onset of their illness. Female chronic depressives also had a significantly greater number of previous illness episodes and a more frequent history of thyroid dysfunction. Personality as measured on the EPO, psychiatric problems arising as secondary complications of the depressive illness, and developmental object loss did not differentiate chronic from non-chronic depressives.