On "Hearing" Voices and "Seeing" Things: Probing Hallucination Predisposition in a Portuguese Nonclinical Sample with the Launay-Slade Hallucination Scale-Revised.

Paula Castiajo,Ana P Pinheiro

doi:10.3389/fpsyg.2017.01138

Paula Castiajo, Ana P Pinheiro

Open Access

https://doi.org/10.3389/fpsyg.2017.01138

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Abstract

The experience of hallucinations is a hallmark of psychotic disorders, but they are also present in other psychiatric and medical conditions, and may be reported in nonclinical individuals. Despite the increased number of studies probing the incidence of nonclinical hallucinations, the underlying phenomenological characteristics are still poorly understood. This study aimed to examine the psychometrics proprieties of the Portuguese adaptation of the 16-item Launay-Slade Hallucinations Scale (LSHS), the phenomenological characteristics of nonclinical hallucinatory experiences in a Portuguese sample, and the relationship between clinical symptoms and hallucination predisposition. Three-hundred-and-fifty-four European Portuguese college students completed the LSHS. Of those, 16 participants with high LSHS scores and 14 with low LSHS scores were further screened for clinical symptoms. A three-factor solution for the LSHS Portuguese version proved to be the most adequate. Intrusive or vivid thoughts and sleep-related hallucinations were the most common. Although, fundamentally perceived as positive experiences, all types of hallucinations were described as uncontrollable and dominating. However, the more pleasant they were perceived, the more controllable they were assessed. In addition, hallucination predisposition was associated with increased clinical symptoms. These results corroborate the lower severity of hallucinations in the general population compared to psychotic individuals. Further, they support an association between clinical symptoms and increased vulnerability to hallucinations. Specifically, increased schizotypal tendencies and negative mood (anxiety and depression) may be related to increased psychotic risk.

Highlights

Hallucinations represent one of the most intriguing phenomena (e.g., Allen et al, 2008), and have been in the spotlight of researchers from many disciplines for decades
Sensitivity The Portuguese version of the Launay-Slade Hallucinations Scale (LSHS) was found to have appropriate sensitivity as all items were successful in discriminating between the five response categories
Portuguese nonclinical individuals were more likely to experience intrusive or vivid thoughts and hypnagogic and hypnopompic hallucinations relative to the other five types of hallucinations, and to perceive their hallucinatory experiences as less unpleasant than what is commonly reported in individuals with a psychotic disorder

Summary

Introduction

Hallucinations represent one of the most intriguing phenomena (e.g., Allen et al, 2008), and have been in the spotlight of researchers from many disciplines for decades. Even though the experience of hallucinations is considered a hallmark of psychotic disorders (e.g., David, 1994; Johns et al, 2004), hallucinations may be present in 10–15% of individuals with no clinical diagnosis (e.g., Barrett and Etheridge, 1992; Paulik et al, 2006; Badcock et al, 2008; Sommer et al, 2010) These findings provided support for a continuum model of psychotic experiences that extends across diagnostic categories, and into the (non-clinical) general population (e.g., Johns and van Os, 2001; Bradbury et al, 2009; Brébion et al, 2010). The occurrence of nonclinical hallucinations represents a risk factor for conversion to full psychosis (e.g., Kelleher and Cannon, 2011), even though it is not necessarily followed by a psychotic diagnosis (Verdoux et al, 1999; Johns and van Os, 2001)

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