Data Point to Potential New Use for Common Antidepressant

The SSRI antidepressant fluoxetine may hold another benefit—helping people with mesial temporal lobe epilepsy who experience learning problems.

Many patients with mesial temporal lobe epilepsy complain of learning and memory problems. So William Gray, M.D., a professor of neurosurgery at Cardiff University in Wales in the United Kingdom, decided to conduct research to better understand the situation and perhaps find a way to remedy these patients’ learning deficits.

First Gray and his colleagues tested 12 mesial temporal lobe epilepsy subjects and 12 healthy control subjects to see how good their learning and memory capabilities were and found that the former group had more learning problems.

They then turned to a rat model for epilepsy and tested rats with this condition for learning and memory abilities. Compared with healthy rats, the rats with the epilepsy-like condition showed evidence of learning and memory deficits, just as the human subjects had.

Further testing suggested that the rats’ learning and memory impairments were due to reduced and abnormal production of new nerves in the hippocampus.

The scientists then gave fluoxetine to the epilepsy rats to see whether it might improve their learning and memory, since fluoxetine is known to improve memory in people with mild cognitive impairment and those with memory difficulties due to chemotherapy, or what is sometimes called “chemo brain” or “chemo fog” (Psychiatric News, March 16).

Fluoxetine did improve learning and hippocampal nerve regeneration in the study rats, but did not show any effect on memory improvement.

Thus fluoxetine might prove useful for improving learning in people with mesial temporal lobe epilepsy, Gray and his colleagues concluded in a report in the August Brain. “A well-tolerated pharmacological therapy that restores learning to normal could be of great clinical benefit,” they wrote.

They also remain hopeful that fluoxetine might help the memories of these epilepsy patients, at least in those with less-severe hippocampal damage, even though their animal tests did not point to this possibility.

The research was funded by Epilepsy Research UK.

An abstract of “Fluoxetine Restores Spatial Learning but Not Accelerated Forgetting in Mesial Temporal Lobe Epilepsy” is posted at http://brain.oxfordjournals.org/content/135/8/2358.abstract. >