Background: Depressive illness in older people causes significant suffering and health service utilisation. Relapse and recurrence rates are high.

Objectives: To examine the efficacy of antidepressants and psychological therapies in preventing the relapse and recurrence of depression in older people.

Search methods: Search of the Cochrane Depression, Anxiety and Neurosis Review Group's specialized register (the CCDANCTR) up to 22 June 2012. The CCDANCTR includes relevant randomised controlled trials from the following bibliographic databases: The Cochrane Library (all years), EMBASE, (1974 to date) MEDLINE (1950 to date) and PsycINFO (1967 to date). We handsearched relevant journals, contacted experts in the field and examined reference lists, conference proceedings and bibliographies.

Selection criteria: Both review authors independently selected studies. We included randomised controlled trials (RCTs) involving people aged 60 and over successfully treated for an episode of depression and randomised to receive continuation and maintenance treatment with antidepressants, psychological therapies, or combination.

Data collection and analysis: Data were extracted independently by the two authors.The primary outcome was relapse/recurrence rate of depression (reaching a cut-off on any depression rating scale) at six-monthly intervals. Secondary outcomes included global impression of change, social functioning, and deaths. Meta-analysis was performed using risk ratio for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals.

Main results: Seven studies met the inclusion criteria (803 participants). Six compared antidepressant medication with placebo; two involved psychological therapies. There was marked heterogeneity between the studies.Comparing antidepressants with placebo, at six months follow-up there was no significant difference. At 12 months follow-up there was a statistically significant difference favouring antidepressants in reducing recurrence compared with placebo (three RCTs, N = 247, RR = 0.67, 95% CI 0.55 to 0.82; NNTB = five). At 24 months there was no significant difference for antidepressants overall, however, for the subgroup of tricyclic antidepressants there was significant benefit (three RCTs, N = 169, RR = 0.70, 95% CI 0.50 to 0.99; NNTB = five). At 36 months there was no significant difference for antidepressants overall. There was no difference in treatment acceptability or death rates between antidepressant and placebo.There was no significant difference between psychological treatment and antidepressant in recurrence rates at 12, 24, and 36 months (one RCT, N = 53) or between combination and antidepressant alone.Overall, the included studies were at low risk of bias.

Authors' conclusions: The long-term benefits of continuing antidepressant medication in the prevention of recurrence of depression in older people are not clear and no firm treatment recommendations can be made on the basis of this review. Continuing antidepressant medication for 12 months appears to be helpful but this is based on only three small studies with relatively few participants using differing classes of antidepressants in clinically heterogeneous populations. Comparisons at other time points did not reach statistical significance. Data on psychological therapies and combined treatments are too limited to draw any conclusions.