Déjà vu! That's what your friends and family members call it when you express a sense of having seen or experienced in the past a situation that occurs in the present.
'Déjà vu' is a French word that literally means 'already seen'. But doctors and experts believe that it is only a false impression and has no such clinically alarming psychological implications.
According to Amitabh Saha, a consultant psychiatrist at the VIMHANS hospital here, almost 70 to 75 per cent of the general population will report having experienced déjà vu at least once in their lifetime.
"It is the experience of feeling sure that one has witnessed or experienced a new situation previously," Sanjay Chugh, leading psychiatrist and founder chairman of the International Institute of Mental Health, told IANS.
Bhawna Sharma, 21, a student, says that she often experiences it.
"Once I was discussing something with a friend and suddenly I felt I have been in the same situation before and that the same discussion had led to a fight previously. So I consciously changed the topic to avoid any argument," she narrated. This, doctors say, is a valid example of déjà vu.
Saha told IANS that out of 1,000 patients in a year, less than five report extreme cases of déjà vu. "Since it is considered a normal phenomenon, most people do not seek assistance. But if a person experiences it frequently, I suggest it should be examined by a specialist," he added.
But why does déjà vu occur? Chugh says that various scientific and non-scientific theories have been offered to explain the rationale behind déjà vu.
"Many researchers have propounded that déjà vu is an abnormality of the memory. The state has also been associated with temporal lobe epilepsy (a chronic neurological condition).
"There are a few reports that suggest the state is due to a mismatching in the brain that causes a person to mistake the present for the past. Many also believe it is related to a past-life experience. And some even attribute it to a simple fantasy or wish fulfilment," Chugh said.
Chugh added that although the state has no serious implications, if a person starts to worry excessively over it, it could become an additional source of stress and anxiety. This in turn might interfere with one's daily functioning.
Samir Parikh, chief of the mental health and behavioural science department, Max Healthcare, further explains that 'déjà vu' is a common phenomenon in everyday life, but it may increase in states of fatigue or intoxication and in association with complex partial attacks or other states of mental illness.
Toward this, Saha added that primarily, déjà vu is found to be more frequent in people addicted to recreational drugs like alcohol and tobacco, those suffering from temporal lobe epilepsy and also those in the early stages of dementia.