Paris syndrome is a transient mental disorder exhibited by some individuals when visiting or going on vacation to Paris, as a result of extreme shock derived from their discovery that Paris is not what they had expected it to be.
The syndrome is characterized by a number of psychiatric symptoms such as acute delusional states, hallucinations, feelings of persecution (perceptions of being a victim of prejudice, aggression, or hostility from others), derealization, depersonalization, anxiety, and also psychosomatic manifestations such as dizziness, tachycardia, sweating, and others, such as vomiting.
Similar syndromes include Jerusalem syndrome and Stendhal syndrome. The condition is commonly viewed as a severe form of culture shock. It is particularly noted among Japanese travelers.
Professor Hiroaki Ota, a Japanese psychiatrist working in France, is credited as the first person to diagnose the condition in 1986. However, later work by Youcef Mahmoudia, physician with the hospital Hôtel-Dieu de Paris, indicates that Paris syndrome is “a manifestation of psychopathology related to the voyage, rather than a syndrome of the traveller. He theorized that the excitement resulting from visiting Paris causes the heart to accelerate, causing giddiness and shortness of breath, which results in hallucinations in the manner similar to the Stendhal syndrome described by Italian psychiatrist Graziella Magherini in her book La sindrome di Stendhal.
Reference : https://en.wikipedia.org/wiki/Paris_syndrome