Abstract

Background

Although the association between depression and excess mortality has been well established, it is not clear whether this is
greater in major depression than in subthreshold depression.

Aims

To compare excess mortality in major depression with that in subthreshold depression.

Method

We searched bibliographic databases and included prospective studies in which both major and subthreshold depression were
examined at baseline and mortality was measured at follow-up.

Results

A total of 22 studies were included. People with major depression had a somewhat increased chance of dying earlier than people
with subthreshold depression but this difference was not significant, although there was a trend (relative risk 1.13, 95%
CI 0.98–1.30, P = 0.1). The population attributable fraction was 7% for major depression and an additional 7% for subthreshold depression.

Conclusions

Although excess mortality may be somewhat higher in major than in subthreshold depression, the difference is small and the
overall impact on excess mortality is comparable.