It is a feeling like no other. A sense of familiarity, a sense that a situation has been lived before, speckled with the tiniest hint of uncertainty. Such is déjà vu. Déjà vu is a strange, unexplainable feeling that many people claim to have experienced. Even with all of its popularity, however, some believe that déjà vu holds little scientific merit. Nonetheless, déjà vu has been intensely discussed and researched for years, and lines have been drawn between whether or not the phenomenon truly exists. Although the debate rages on, more light can be shed on whether or not déjà vu is real through an inspection of its symptoms, its association to other conditions, and its relation to the use of drugs.
If déjà vu is truly something that affects people, then there must be statistics and symptoms that demonstrate this. Findings relayed in The Journal of Nervous & Mental Disease in 2003 reported that in a survey of 386 healthy adults, approximately 76% of them experienced déjà vu (Adachi, et al. Demographic 242). Interestingly enough, a difference was not seen in the frequency of déjà vu between respondents of opposing genders (242). Although a universal cause of déjà vu has not been established, some researchers believe that there are over “50 different explanations for the déjà vu phenomenon” (Neppe 63). Signs of the sensation, on the other hand, are much more readily seen. Commonly reported symptoms of déjà vu include being sensitive to repetitive themes as well as the notion that certain circumstances have been experienced before. This can be anything from having met someone to having been in a particular place. These feelings are usually accompanied with an inexplicable eeriness that can lead to more intense problems such as insomnia, anxiety, and profuse sweating. However, déjà vu is much more than a short list of symptoms. Research done by Dr. Vernon Neppe in 2010 reported four subtypes of déjà vu, all with varying signs and prevalence. For example, Associative Déjà vu happens to most people, but only for a few seconds a few times in their entire life, whereas Temporal Lobe Epileptic Déjà vu is less common but was seen in some subjects up to nine times a day (66-67). From this account déjà vu may appear to be real, but it may very well be a complication of other ailments.
When it comes to medicine, it is not unusual to see ties between several conditions in a patient. This fact has led researchers to work tirelessly in an attempt to find an association between déjà vu and any other disease to prove that the phenomenon is real. One primary candidate for such a linkage was schizophrenia due to its similar psychological make-up in people. However, results collected from studies showed not only that déjà vu was more common in healthy patients than those with schizophrenia, but also that subjects who were noticeably more schizophrenic experienced déjà vu less frequently (Adachi, Schizophrenia 592). From this, researchers agreed that there was no significant link between déjà vu and schizophrenia, a large blow to the scientific credibility of the phenomenon. Conversely, further investigation into the matter has now discovered a possible connection between déjà vu and disease of the temporosphenoidal region of the brain, particularly tumors and Temporal Lobe Epilepsy. This has even led to the classification of a condition, called Temporal Lobe Epileptic Déjà Vu, which can be very repetitive and may demonstrate features similar to a seizure. For as substantial an impact that this has had on the scientific community, drawbacks have been identified. Along with the discovery of Temporal Lobe Epileptic Déjà Vu, other subtypes of the condition have been found, some of which even involve “illogicality” and “time distortion” as well as other cornerstones of parapsychology. This makes for one step forward and two steps back as researchers attempt to climb the slippery slope of déjà vu (Neppe 67).
Déjà vu may not be a symptom of other conditions, but rather of the drugs used to treat them. According to a medical case report, “intense, protracted déjà vu, lasting for several hours” was seen in a female patient given the drug 5-hydroxytryptophan to treat a completely different issue (Kalra, et al. 311). Another well-known example of déjà vu being triggered by medicine is that of amantadine and phenylpropanolamine, both of which are commonly used to treat the flu (Taminien 460). Though this demonstrates a large claim that déjà vu does hold medical significance, it still cannot explain why the phenomenon is observed so frequently and more importantly, in people who are not taking any medication. Drawing farther away from this is the notion that some consider déjà vu to be the manifestation of a suppressed fantasy or a waking dream, with psychoanalyst Sigmund Freud being the most famous proponent of this idea (Wild 3). The thought of such a well-known sensation as a mere reverie is an explanation that is primarily harmless and not medically stimulating, leading only to more questions asked than answered in the case of déjà vu.
Déjà vu has echoed through the ages since people like Pythagoras and St. Augustine first described it thousands of years ago. For as much as it has been written about and observed however, there is still very much that is unknown about the condition. Headlining this list is whether or not it can truly be classified as ‘condition’. Déjà vu is an ordinary occurrence, has a commonality in its symptoms between people, and has even been tied to some other diseases and types of medication. In spite of this, research has yet to identify what triggers an episode and why it is so apparently harmless. All that can be established at the current time is that déjà vu is conclusive with all people, both healthy and ill. For as persistent as experts have been, déjà vu remains an unsolvable puzzle.
Adachi, Naoto, Takuya Adachi, and Michihiro Kimura. “Demographic and Psychological Features of Déjà Vu Experiences in a Nonclinical Japanese Population.” The Journal of Nervous and Mental Disease 191.4 (2003): 242-47. The Journal of Nervous and Mental Disease. Lippincott Williams & Wilkins, Apr. 2003. Web. 20 July 2011.
Adachi, Naoto, Takuya Adachi, and Nozomi Akanuma. “Déjà Vu Experiences in Schizophrenia: Relations with Psychopathology and Antipsychotic Medication.”Comprehensive Psychiatry 48.6 (2007): 592-96. Science Direct, 20 Aug. 2007. Web. 20 July 2011.
Kalra, Seema, Andrew Chancellor, and Adam Zeman. “Recurring déjà vu associated with 5- hydroxytryptophan.” Acta Neuropsychiatrica 19.5 (2007): 311-313. Academic Search Complete. EBSCO. Web. 23 July 2011.
Neppe, Vernon M. ” Déjà Vu: Origins and Phenomenology: Implications of the Four Subtypes for Future Research.” The Journal of Parapsychology 74.1 (2010): 61-99. Find Articles. CBS Interactive, 1 Apr. 2010. Web. 20 July 2011.
Taminien, Tero, and Satu K. Jääskeläinen. “Intense and Recurrent Déjà Vu Experiences Related to Amantadine and Phenylpropanolamine in a Healthy Male.” Jorunal of Clinical Neuroscience 8.5 (2001): 460-62. Science Direct. Elsevier B.V., Sept. 2001. Web. 24 July 2011.
Wild, Edward. “Déjà vu in neurology.” Journal of Neurology 252.1 (2005): 1-7. Academic Search Complete. EBSCO. Web. 24 July 2011.