Multisite, open-label, prospective trial of lamotrigine for geriatric bipolar depression: a preliminary report

Aims: This is a multisite, 12-week, open-label trial of lamotrigine augmentation in 57 older adults (≥ 60 years; mean ± SD age = 66.5 ± 6.7 years) with either type I or type II bipolar depression.

Methods: Primary outcome measure was change from baseline on the Montgomery-Åsberg Depression Rating Scale (MADRS). Secondary outcome measures included Hamilton Depression Rating Scale (HAM-D), Clinical Global Impression-Bipolar version (CGI-BP), and the WHO-Disability Assessment Schedule II (WHO-DAS II). The Udvalg for Kliniske Undersøgelser (UKU) was used to assess side effects.

Results: A total of 77.2% of the study subjects had bipolar I disorder. The mean (SD) lamotrigine dose was 150.9 (68.5) mg/day. There was significant improvement in the MADRS, HAM-D, CGI-BP, and in most domains on the WHO-DAS II. For patients for whom final MADRS score was available: 31 (57.4%) met remission criteria and 35 (64.8%) met response criteria. There were 19/57 (33.3%) who dropped out of the study prematurely, with 6 dropouts due to adverse events (4 cases of rash, 1 manic switch, and 1 hyponatremia). Two cases of rash were possibly drug related and were resolved with drug discontinuation. The most common UKU adverse effects were reduced sleep duration (n = 14, 24.6%), weight loss (n = 12, 21.1%), increased dream activity (n = 12, 21.1%), polyuria/polydipsia (n = 11, 19.3%), weight gain (n = 9, 15.8%), diminished sexual desire (n = 9, 15.8%), increased sleep (n = 9, 15.8%), lassitude/fatigue (n = 8, 14%), and unsteady gait (n = 8, 14%). No significant changes in electrocardiogram or laboratory tests were observed.

Conclusions: In bipolar depressed elders, lamotrigine was associated with improvement in depression, psychopathology, and functional status. There was a moderate number of adverse events, although relationship of adverse events (particularly falls) to study medication could not be clearly determined in this uncontrolled trial. Controlled studies are needed to further evaluate efficacy and tolerability of lamotrigine therapy in geriatric bipolar depression.