Imagine constantly feeling like you’ve read that newspaper article before, or have heard those radio presenters having the exact same discussion previously. Thankfully, for the vast majority of us, these weird feelings, or déjà vu, are random and infrequent. But for one man, this sense of familiarity is so persistent that it has become debilitating. What’s more, the feelings seem to stem from anxiety rather than a neurological disorder, which is the first time such a case has been documented.
Déjà vu, which literally translates to ‘already seen,’ is that eerie, overwhelming feeling of familiarity that sometimes occurs with a novel experience, such as visiting a new place or having a specific conversation with someone. It’s estimated that around 70% of the population has experienced déjà vu at some stage, with a higher incidence occurring in individuals between the ages of 15 and 25. Despite its common nature, scientists know very little about it because it’s extremely unpredictable and therefore difficult to study.
What we do know about déjà vu has mainly come from studies on patients with a specific type of epilepsy, called temporal lobe epilepsy, as the phenomenon sometimes forms part of the seizures in these individuals. Some dementia patients also experience chronic déjà vu. While it has been extensively investigated in these groups, studies in other clinical populations are scarce. Now, for the first time, scientists have described the first documented case of so-called “psychogenic déjà vu,” meaning that it originates from the mind, rather than having a physiological basis.
The individual is a 23-year-old British male who began experiencing déjà vu back in 2007, shortly after starting university. He had a history of feeling anxious and had obsessive-compulsive tendencies, in particular over hygiene. His anxiety worsened over time, leading him to take a break from his studies. It was during this time that he started experiencing episodes of déjà vu, some of which were frightening.
After returning to university, his episodes became more intense, and then fairly continuous after trying the drug LSD. The déjà vu was so persistent that he eventually stopped watching television, listening to the radio and reading newspapers or magazines because he felt he had heard or seen it all before.
He was referred to specialists in 2008 for neurological examination, which didn’t seem to indicate any physiological problems. His EEG and MRI scans were all normal, and he performed similarly to control groups on memory tests.
Scientists aren’t sure what’s going on, but according to case report author Christine Wells, it could be due to abnormal nerve activity. “The general theory is that there’s a misfiring of neurons in the temporal lobes—which deal with recollection and familiarity,” explains Wells. “That misfiring during the process of recollection means we interpret a moment in time as something that has already been experienced.”
It’s therefore possible that the individual’s anxiety is causing a bunch of neurons in his brain to fire inappropriately, causing the déjà vu which then unfortunately leads to more anxiety, triggering the process to start again.
[Via the Journal of Medical Case Reports and New Scientist]