Today's approaches to dissect the neurobiology of depression employ an unprecedented array of experimental techniques in humans and animals, including genome-wide DNA sequencing, chromatin immunoprecipitation to study epigenetic factors, functional brain imaging, optogenetic electrophysiological tools, viral-mediated gene transfer and an impressive assortment of genetic mutant mice. The list of molecular players involved in depression's phenotypes has now expanded to include genes from diverse aspects of cellular physiology such as numerous neurotransmitter and neuropeptide systems, steroid hormones, neurotrophic and cytokine signaling cascades, ion channels, circadian genes, phytochemicals, and many others. Most of the new targets are derived from experiments in rodents and, while these studies are scientifically sound, the targets themselves may or may not be therapeutically relevant or feasible for human depression.

This special issue in the journal BIOCELL is intended to new molecules and new approaches for treatment of depression in preclinical and clinical studies.