Déjà Vu 101: What The Research Says, Spiritual Explanations & More

Déjà vu is a sense that your current experience has happened before, registered clinical counselor Leslie Ellis, Ph.D., tells mbg. The term itself is French for "already seen," which succinctly describes exactly what déjà vu is all about.

One 1992 study on déjà vu defines it as "a dissociative phenomenon which can be characterized as a subjectively inappropriate impression of familiarity of the present with an undefined past."

According to Ellis, almost everyone experiences déjà vu sometimes, with roughly two-thirds (60 to 70%) of people experiencing it "fairly regularly."

It's thought to happen less as we get older1 and appears to be associated with stress and fatigue. The phenomenon is particularly common among people with temporal-lobe epilepsy and some other psychiatric conditions, according to research on epileptic patients—with virtually all people with epilepsy having experienced déjà vu. Interestingly, the sensation often happens right before a seizure, which is known as "ictal déjà vu." Other research has also linked it with dementia2.

"Temporal lobe epilepsy, migraines, anxiety, and dissociation can be associated with more frequent and extended déjà vu experiences," Ellis notes, adding, "Neurobiologists suggest it could be explained by parts of our brain being out of sync, and they have been able to induce déjà vu in the lab by stimulating specific cortical structures."

All that to say, déjà vu is common, and while it can be related to certain conditions, it is not a cause for alarm. "Déjà vu can warn of epilepsy or other neurological issues, but in most cases, it is a benign and mysterious experience to wonder about and enjoy," Ellis says.

As Ellis explains, "Neuroscientists have identified the temporal region as the location in the brain responsible for the experience of déjà vu but not the reason behind it." There has been extensive research on the topic, though she adds the actual cause of it remains a mystery.

Implicit memory involves a previous setting that someone has indeed experienced before, but the scene was "stored in such an indistinct manner that only the sense of familiarity is resurrected."

Ellis, who is very privy to the world of dreams and the unconscious, tells mbg that much speculation exists around déjà vu and how it relates to our dreams, reincarnation, and unconscious memories.

Déjà vu has also been associated with precognitive dreaming (aka dreams that seemingly predict the future) and déjà rêvé, which translates to "already dreamed" and describes the sensation that you've dreamed about something before it happened in real life.