Depression is associated with atrophy in several brain structures, with the hippocampus seemingly most affected. A wide variety of cellular mechanisms have been proposed for these structural changes. While impaired neurogenesis alone is inadequate to account for such marked changes, an altered rate of neurogenesis is likely to affect hippocampal function. There is also strong evidence for neurotransmitter and glucocorticoid-mediated effects on neurogenesis, providing routes for actions of antidepressants. As a consequence of this, neurogenesis provides an explanation for the ‘conventional monoaminergic theory of depression’ and also an explanation for the modulation of neurogenesis, and therefore depression, by antidepressant medication.
Keywords: depression, neurogenesis, neurotransmitters, glucocorticoids, trophic factors