Gradual discontinuation of lithium augmentation in elderly patients with unipolar depression.

Recently, the therapeutic benefit of lithium augmentation in old age has come into question. These data, in light of the documented high incidence of side effects after lithium use in elderly patients, resulted in the design of a prospective, placebo-controlled lithium augmentation withdrawal study in elderly patients with unipolar depression. Twelve eligible geriatric patients (10 women and 2 men; mean [+/-SD] age, 76.2 +/- 5.7 years) with DSM-III-R unipolar depression receiving adjunct lithium therapy were randomized to receive continued lithium augmentation or matching placebo (withdrawal rate 150 mg/day/wk). At each clinic visit, patients were assessed for depression (Montgomery-Asberg Depression Rating Scale and Geriatric Depression Rating Scale) and lithium-induced toxicities (a 21-item side-effect checklist, renal and thyroid biochemistry). Over the 2-year observation period, the placebo group reported a decrease in composite 21-item side-effect score and specific lithium toxicities (e.g., urinary urgency, hand tremor, and renal/thyroid abnormalities). Two patients in the lithium maintenance group had a recurrence of depression at 61 and 96 weeks, respectively, immediately after a stressful life event (cerebrovascular accident [CVA] or death of spouse), and two patients had a recurrence in the placebo group at 7 and 92 weeks, respectively, without any apparent changes in life stresses. No other prognostic risk factors for recurrence were identified. Depression that recurred in patients who were receiving placebo was relatively resistant to reinstitution of lithium augmentation therapy. In otherwise stable geriatric patients with unipolar depression, the documented benefits of reduced side effects should be weighed against the risk of recurrence and subsequent lithium resistance before withdrawal of lithium augmentation.