Predictors of recurrence in remitted late-life depression

Background: Late-life depression (LLD) is associated with a fragile antidepressant response and high recurrence risk. This study examined what measures predict recurrence in remitted LLD. Methods: Individuals of age 60 years or older with a Diagnostic and Statistical Manual - IV (DSM-IV) diagnosis of major depressive disorder were enrolled in the neurocognitive outcomes of depression in the elderly study. Participants received manualized antidepressant treatment and were followed longitudinally for an average of 5 years. Study analyses included participants who remitted. Measures included demographic and clinical measures, medical comorbidity, disability, life stress, social support, and neuropsychological testing. A subset underwent structural magnetic resonance imaging (MRI). Results: Of 241 remitted elders, approximately over 4 years, 137 (56.8%) experienced recurrence and 104 (43.2%) maintained remission. In the final model, greater recurrence risk was associated with female sex (hazard ratio [HR]=1.536; confidence interval [CI]=1.027-2.297), younger age of onset (HR=0.990; CI=0.981-0.999), higher perceived stress (HR=1.121; CI=1.022-1.229), disability (HR=1.060; CI=1.005-1.119), and less support with activities (HR=0.885; CI=0.812-0.963). Recurrence risk was also associated with higher Montgomery-Asberg Depression Rating Scale (MADRS) scores prior to censoring (HR=1.081; CI=1.033-1.131) and baseline symptoms of suicidal thoughts by MADRS (HR=1.175; CI=1.002-1.377) and sadness by Center for Epidemiologic Studies-Depression (HR=1.302; CI, 1.080-1.569). Sex, age of onset, and suicidal thoughts were no longer associated with recurrence in a model incorporating report of multiple prior episodes (HR=2.107; CI=1.252-3.548). Neither neuropsychological test performance nor MRI measures of aging pathology were associated with recurrence. Conclusions: Over half of the depressed elders who remitted experienced recurrence, mostly within 2 years. Multiple clinical and environmental measures predict recurrence risk. Work is needed to develop instruments that stratify risk.