A study identifies areas of the genome involved in the response to lithium in bipolar disorder

Researchers from Hospital Clínic, IDIBAPS, University of Barcelona (UB) and Mental Health Research Center (CIBERSAM), associated with Institute of Health Carlos III (ISCIII), have taken part in an international study, published in the prestigious journal The Lancet, where a region of the genome involved in the response to lithium in bipolar disorder has been discovered. This study is the largest genetic analysis using GWAS (Genome-Wide Association Study) carried out regarding the response to this medication so far and included data from more than 2,500 patients with the disease.

Doctors Antonio Benabarre, Francesc Colom, Esther Jiménez and Eduard Vieta, from Bipolar Disorders Unit and Research Group of Clinic and IDIBAPS, along with doctors. Bárbara Arias and Marina Mitjans, from Anthropology Unit of the Faculty of Biology (UB), took part in this study in the international Consortium of ConLiGen framework.

Lithium is the first choice treatment for bipolar disorder (BD), a chronic disease that causes episodes characterized by shifts in mood. Little is known about its mechanism of action and previous studies suggest that patient’s response to lithium may have a genetic background, although the results are not reproducible or conclusive.

The study published by The Lancet, researchers have evaluated clinical and genetic data from more than 2,500 patients with BD in orderto determinate which areas of the genome are involved in the response to lithium treatment . Results show the association between some genetic variants in the chromosome 21 and the response to this medication. The genetic region associated includes other two long non-coding RNA areas.

To validate if these identified regions are related to treatment response, researchers of consortium carried out a study with 73 patients treated with lithium in single-drug therapy for 2 years and proved that genetic markers found help predict relapses of BD patients when treated with lithium.

Dr Eduard Vieta explains that “the importance of these results is twofold. On one hand, they help to identify patients who may respond favourably to lithium, in a step towards personalised medicine applied to mental health. And on the other hand, they suggest the existence of a new lithium mechanism of action which could lay the basis for more effective and safety future treatments”.

Reference article:

Genetic variants associated with response to lithium treatment in bipolar disorder: a genome-wide association study

Liping Hou, Urs Heilbronner, Franziska Degenhardt, Mazda Adli, Kazufumi Akiyama, Nirmala Akula, and others

Lancet. 2016 Jan 21. pii: S0140-6736(16)00143-4. doi: 10.1016/S0140-6736(16)00143-4.