The role of clock genes in the etiology of Major Depressive Disorder: Special Section on "Translational and Neuroscience Studies in Affective Disorders". Section Editor, Maria Nobile MD, PhD. This Section of JAD focuses on the relevance of translational and neuroscience studies in providing a better understanding of the neural basis of affective disorders. The main aim is to briefly summaries relevant research findings in clinical neuroscience with particular regards to specific innovative topics in mood and anxiety disorders.

BACKGROUND: Circadian rhythms are largely dysregulated in Major Depressive Disorder (MDD). The present review provides a summary of the findings about the role of clock genes in the etiology of MDD.

METHODS: A careful search of articles on Pubmed, PsycINFO, Isi Web of Knowledge was performed in order to obtain a comprehensive review about the topic.

RESULTS: The studies reported contrasting results about the association of different single nucleotide polymorphisms (SNPs) in clock genes and MDD. The most consistent result reported the association between SNP rs2287161 of CRY1 and MDD development.

LIMITATIONS: Most of the published papers on the topic show bias as a prevalence of Asian ethnicity or not blinded conditions of laboratory experiments with respect to subjects' conditions (healthy controls or MDD).

CONCLUSION: Further epigenetic and genome-wide studies are necessary to have a more clear idea about the role of clock genes in the etiology of MDD.