The seizure therapy, when administered repeatedly, resulted in a 50 percent increase of neurons in the hippocampus, which the researchers say they'd expected. The chemical antidepressants produced a 20 to 40 percent increase in neurons, they say, and the antipsychotic drug did not produce any significant change. Sustained use of the antidepressant drugs was necessary, however, to lead to significant cell change, the study says. Results were seen after 14 to 28 days of administration, a time frame the researchers consider consistent with therapeutic regimens. Findings appear in the current issue of the Journal of Neuroscience .
Most antidepressants work by regulating the amounts of chemicals released into the brain.
For example, the popular medication Prozac specifically increases levels of the neurotransmitter serotonin, while other drugs on the market target combinations of brain chemicals. In a sense, he suggests, this is just the tip of the iceberg. However, Bodkin cautions that the results could be the result of an incidental effect of antidepressants in the laboratory, unrelated to the main effect of antidepressants in people. That's very far from depressed patients. That's a lovely thing to hope for, but there's much more work to be done.