Contrary to what many people believe, a full moon does not cause seizures in patients with epilepsy, new research indicates. However, non-epileptic type seizures do seem to be more common during a full moon.

Non-epileptic seizures differ from epileptic ones in that they are not caused by electrical disturbances in the brain, but rather by psychologic or physiologic conditions, such as stress or low blood sugar.

“Contrary to the myth, epileptic seizures are not more common during a full moon,” lead author Dr. Selim R. Benbadis, from the University of South Florida in Tampa, said in a statement. “In fact, we found the number of epileptic seizures was lowest during the full moon and highest in the moon’s last quarter.”

Benbadis’s team reviewed the occurrence of seizures at their epilepsy-monitoring unit during a 3-year period. The researchers calculated the number and type of seizures that occurred during the four phases of the moon, according to the report in the journal Epilepsy and Behavior.

A total of 770 seizures were logged during the study period, including 470 epileptic and 300 non-epileptic seizures.

In the overall analysis, seizures occurred with similar frequency during each of the moon phases. As noted, however, non-epileptic seizures were more common during a full moon phase, whereas epileptic seizures were most common during the last quarter.

The results suggest that the “full moon” theory for epileptic seizures is a myth. As to why this myth has persisted for so long, Benbadis said that “some people still seem to like poetic, mysterious and irrational explanations for puzzling diseases like epilepsy.”

SOURCE: Epilepsy and Behavior, May 25th online issue, 2004.