Déjà rêvé is a French phrase that translates to "already dreamed". It is a phenomenon where an individual feels like they have already experienced a current situation in a dream or that they are in a dream while awake. Déjà rêvé is a more complex sensation than déjà vu, which is the feeling of having already seen a current situation.

Research on déjà rêvé is limited, but a 2010 study found that experiencing déjà rêvé is common, although it gets less common with age. Another study in 2018 found that déjà rêvé is a generic term for three distinct entities: the recollection of a specific dream, reminiscence of a dream-like state, and the sudden entry into a dream state.

The causes of déjà rêvé are not fully understood, but it is believed to be a normal phenomenon that responds to certain strange factors. For example, those with epilepsy who have had seizures in their brains frontal lobes are particularly prone to déjà vu, and researchers have found that when two circuits in the hippocampus are activated at once, we get an experience of déjà vu.

In conclusion, déjà rêvé is a phenomenon where an individual feels like they have already experienced a current situation in a dream or that they are in a dream while awake. It is a more complex sensation than déjà vu, and research on it is limited. Although the causes of déjà rêvé are not fully understood, it is believed to be a normal phenomenon that responds to certain strange factors.