Mini review: Recent advances on epigenetic effects of lithium

•Genetic and environmental factors play a role in lithium response variability.•Epigenetic mechanisms mediate the interplay between genetic and environmental factors.•Pre-existing or Li-induced epigenetic marks may play a role in Li response.•Epigenetic measures could shorten the time to identify lithium response status. Lithium (Li) remains the first line long-term treatment of bipolar disorders notwithstanding a high inter-individual variability of response. Significant research effort has been undertaken to understand the molecular mechanisms underlying Li cellular and clinical effects in order to identify predictive biomarkers of response. Li response has been shown to be partly heritable, however mechanisms that do not rely on DNA variants could also be involved. In recent years, modulation of epigenetic marks in relation with the level of Li response has appeared increasingly plausible. Recent results in this field of research have provided new insights into the molecular processes involved in Li effects. In this review, we examined the literature investigating the involvement of three epigenetic mechanisms (DNA methylation, noncoding RNAs and histone modifications) in Li clinical efficacy in bipolar disorder.