Age-Stratified Lithium Therapeutic Ranges for Older Adults with Bipolar Disorder - from Awareness to an Action Plan

Lithium is the first-line treatment for maintenance therapy in bipolar disorder. It is an effective mood stabilizer agent, and may have potential benefits in neuroprotection and reducing the risk of suicide. Toxicity has been a concern in recent decades, particularly in older adults (≥60 years). In 2019, the Older Adults Task Force within the International Society for Bipolar Disorder (ISBD) published recommendations for age-stratified lithium therapeutic ranges for therapy of Older Age Bipolar Disorder (OABD), namely 0.4 - 0.8 mmol/L for ages 60 to 79 and 0.4 - 0.7 mmol/L for ages 80 and above. Clinical laboratory practice surveys in Canada indicated that adoption and implementation of the proposed ranges has been limited to date. In this article, we describe the approach and steps taken to evaluate and implement recommended lithium therapeutic ranges in Ontario and other provinces in Canada for laboratory quality improvement. Sources of variation in lithium reporting practices are discussed and shared here to highlight potential barriers to implementation. The overall goal of this article is to bring attention across the global laboratory community that lower lithium therapeutic target ranges in older patients are crucial for patient safety in OABD.