Response to lithium treatment in bipolar disorder as a pharmacogenetic phenotype

Family, twin, and adoption studies have provided consistent evidence supporting the role of genes in the predisposition to bipolar disorder (BD). Lithium has been one of the most commonly prescribed prophylactic treatments for BD and although it is a clearly effective mood stabilizer, its effectiveness tends to vary depending on clinical presentation and side-effect profile. Pharmacogenetic studies can be useful to elucidate genetic factors that may play a role in modulating lithium response. This strategy has provided hope for advancements in understanding the genetics of lithium responsive BD, and eventually, setting up the foundations for a more personalized treatment of BD patients. This article briefly reviews possible molecular mechanisms of lithium action and discusses genetic studies that have focused on lithium response. Although data examining the pharmacogenetics of BD remain scarce, the study of lithium response is an important and promising avenue to better understanding the BD phenotype, as well as genetic mechanisms that may be involved in BD and mood stabilization.