Last week the Journal of Neuroscience published findings suggesting antidepressant treatment stimulates neurogenesis in primates, something researchers had spotted in rodents and tree shrews previously. These results, which report neurogenesis in monkeys undergoing electroconvulsive shock (ECS), come close to confirming a hunch by Brain Cells Inc, a company I profiled in the April issue of The Scientist. Brain Cells is currently banking millions on the idea that human antidepressant treatments work via neurogenesis. Indeed, two of the paper's co-authors are founders of Brain Cells Inc. The company's approach to finding new antidepressants is to screen drugs for neurogenic properties, and it is in the process of raising funds to take one such drug to clinical trials.

But it's still preliminary. Monkey data don't always apply to humans, and it remains to be seen whether the ECS-induced neurogenesis in primates can also be induced by drugs. The other fundamental question is whether neurogenesis is sufficient for, or even related to, antidepressant effects. As the authors write, 'It is indeed possible that antidepressant-induced neurogenesis is an epiphenomenon unrelated to therapeutic effects.' Stay tuned as The Scientist tracks the story.

L. Santarelli et al., 'Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants,' Science, 301:805-9, 2003.

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P.S. Erikkson et al., 'Neurogenesis in the adult human hippocampus,' Nature, 4:1313-7, 1998.

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J.E. Malberg et al., 'Chronic antidepressant treatment increases neurogenesis in adult rat hippocampus,' The Journal of Neuroscience, 20:9104-10, 2000.

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