A neurogenic theory of depression gains momentum

The rate of adult neurogenesis fluctuates in response to several environmental factors. Chronic stress, which can lead to neuronal apoptosis and dendritic atrophy, certainly affects the overall rate of neurogenesis in the adult brain. Depression, which arises from several causes, including chronically stressful situations, is known to correlate with altered hippocampal morphology. But is the link between depression and neuronal regeneration merely coincidental? Recent studies indicate that ingestion of antidepressants leads to increased neurogenesis in the hippocampus. However, the hippocampus is generally thought important for learning and memory-not for "mood" state-thus, there is much more to the story that requires clarification. Also, caveats abound in the interpretation of neurogenesis in the amelioration of depression; nonetheless, these results are quite intriguing and might point to better design and prediction of new-generation antidepressants.