Validation Study of Italian Version of Inventory for Déjà Vu Experiences Assessment (I-IDEA): A Screening Tool to Detect Déjà Vu Phenomenon in Italian Healthy Individuals.

Andrea Romigi,Antonio Augimeri,Francesca Bisulli,Laura Mumoli,Edoardo Ferlazzo,Antonio Gambardella,Giancarlo Di Gennaro,Vito Sofia,Sara Gasparini,Angelo Labate,Maria Grazia Vaccaro ,Leila Zummo,Giovanni Tripepi,Umberto Aguglia,Rossella Baggetta,Antonella Bruni,A T Giallonardo ,Ornella Daniele,Aldo Quattrone,Carlo Di Bonaventura,S Ló Nigro ,Paolo Tinuper,Salvatore Maria Cavalli ,Jinane Fattouch,Alfredo D’Aniello,Alessandra Ferrari

doi:10.3390/bs7030050

Abstract

The Inventory Déjà Vu Experiences Assessment (IDEA) is the only screening instrument proposed to evaluate the Déjà vu (DV) experience. Here, we intended to validate the Italian version of IDEA (I-IDEA) and at the same time to investigate the incidence and subjective qualities of the DV phenomenon in healthy Italian adult individuals on basis of an Italian multicentre observational study. In this study, we report normative data on the I-IDEA, collected on a sample of 542 Italian healthy subjects aging between 18–70 years (average age: 40) with a formal educational from 1–19 years. From September 2013 to March 2016, we recruited 542 healthy volunteers from 10 outpatient neurological clinics in Italy. All participants (i.e., family members of neurological patients enrolled, medical students, physicians) had no neurological or psychiatric illness and gave their informed consent to participate in the study. All subjects enrolled self-administered the questionnaire and they were able to complete I-IDEA test without any support. In total, 396 (73%) of the 542 healthy controls experienced the DV phenomenon. The frequency of DV was inversely related to age as well as to derealisation, jamais vu, precognitive dreams, depersonalization, paranormal activity, remembering dreams, travel frequency, and daydreams (all p < 0.012). The Italian version of IDEA maintains good properties, thus confirming that this instrument is reliable for detecting and characterising the DV phenomenon.

Highlights

The Déjà vu (DV) experience is defined as “any subjectively erroneous feeling of familiarity for present experience with an undefined past” [1]
The original English version was forward-translated by two independent translators—an English native speaker teacher and a doctor fluent in English—and their translation agreed with a final Italian version
In 2001, Adachi et al [6] published the Japanese version of the Inventory Déjà Vu Experiences Assessment (IDEA) for which validity and reliability were equivalent to those of the English version

Summary

Introduction

The Déjà vu (DV) experience is defined as “any subjectively erroneous feeling of familiarity for present experience with an undefined past” [1]. The DV phenomenon has aroused significant interest in scientific literature because many aspects of DV are still obscure. A scale-self-administered questionnaire called the Inventory Déjà Vu Experiences Assessment (IDEA) is the only instrument validated and able to measure the frequency of occurrence and the psycho-behavioural consequences of having DV [5]. The IDEA represents a valuable method to explore the impact and the features of DV. It is a 23-item self-administered questionnaire containing a general section of nine questions and a qualitative section of 14 sections focusing on the qualitative characteristic of the DV experiences. Our purpose is to validate the Italian version of the IDEA (I-IDEA) and at the same time investigate the incidence of the DV phenomenon among healthy

Objectives

Methods

Conclusion