According to the World Health Organization, depression has now surpassed HIV, AIDS, malaria, diabetes, and war as the leading cause of disability. Current antidepressants may take weeks to months to be effective. Unfortunately, one-third of patients are still unresponsive, and are called “treatment-resistant.” However, there are other options available.
Researchers hypothesize that neurogenesis, or neuron growth, is an antidepressant action. This hypothesis is linked to the understanding that nearly all antidepressants increase birth of granule neurons in rodents. Ketamine, however, has such rapid antidepressant effects, within hours, suggesting that the mechanisms involved with ketamine are not involved with neuron birth. Instead, researchers hypothesized that ketamine’s rapid effects are due to it enhancing the maturation of neurons born previously.
