Study of the Genetic and Environmental Factors of Vulnerability in Bipolar Disorders

Bipolar disorder is a complex, multifactorial disorder with the intervention of genetic vulnerability factors. To help the identification of these genetic factors and to improve genotype-phenotype correlation, the identification of endophenotype through the exploration of vulnerability characteristics in unaffected first degree relatives have been recommended. For this purpose, the investigator include bipolar patients, unaffected first degree relatives and control subjects to perform genetic association studies and subphenotype analyses. In this study the investigator will focus on subgroups defined according to the existence of abnormal circadian rhythm (a major indicator of bipolar vulnerability). Lithium is the leading treatment of bipolar disorders but prophylactic lithium response is highly variable and difficult to predict due to lack of biomarkers of response. To explore lithium response variability and to identify biomarkers of response, the investigator characterise lithium response using "ALDA" scale to conduct pharmacogenetic studies and pharmacokinetic studies of lithium extended release, in the subpopulation of patients treated with lithium. As lithium is a circadian agent, the investigator will also explore the links between lithium response and circadian phenotypes. Finally, using Li7 magnetic spectroscopy, the investigator will compare lithium brain distribution in a small sample of good and partial responders to lithium.