Perceptual abnormalities related to sensory gating deficit are core symptoms in adults with ADHD.

This study investigated and compared perceptual abnormalities related to sensory gating deficit in adult patients with Attention Deficit Disorder with Hyperactivity (A-ADHD) and adult patients with schizophrenia. Subjects were evaluated with the Sensory Gating Inventory (SGI). We compared SGI scores between patients with A-ADHD, patients with schizophrenia and healthy subjects. We also assessed the relationship between SGI scores and clinical symptoms, and evaluated the ability of the SGI to detect perceptual abnormalities in A-ADHD. Seventy adult patients with ADHD reported higher SGI scores than the 70 healthy subjects and the 70 patients with schizophrenia. The inattention factor of the ASRS correlated significantly with the overall SGI score. The ROC AUC for the overall SGI score in the A-ADHD group (versus the healthy group) illustrated good performance. The findings suggest that i) perceptual abnormalities are core symptoms of adult patients with ADHD and ii) the attention of patients with A-ADHD may be involuntarily drowned by many irrelevant environmental stimuli leading to their impaired attention on relevant stimuli. They also confirm that the SGI could be a useful self-report instrument to diagnose the clinical features of A-ADHD.

Validation of the French sensory gating inventory: a confirmatory factor analysis.

The Sensory Gating Inventory (SGI) is an instrument investigating daily experiences of sensory gating deficit developed for English speaking schizophrenia patients. The purpose of this study is to design and validate a French version of the SGI. A forward-backward translation of the SGI was performed. The psychometric properties of the French SGI version were analyzed. A confirmatory factor analysis (CFA) was carried out to determine whether factor structure of the French version is similar to the original English version. In a sample of 363 healthy subjects (mean age=31.8 years, S.D.=12.2 years) the validation process revealed satisfactory psychometric properties: the internal consistency reliability was confirmed for each dimension; each item achieved the 0.40 standard threshold for item-internal consistency; each item was more highly correlated with its contributive dimension than with the other dimensions; and based on a CFA, we found a 4-factor structure for the French version of the SGI similar to the original instrument. Test-retest reliability was not determined. The French version of the SGI is a psychometrically sound self-report for measuring phenomenological sensory gating experiences.

Do schizophrenia patients with low P50-suppression report more perceptual anomalies with the sensory gating inventory?

BACKGROUND: P50 amplitude changes in dual click conditioning-testing procedure might be a neurophysiological marker of deficient sensory gating in schizophrenia. However, the relationship between abnormalities in the neurophysiological and phenomenological dimensions of sensory gating in schizophrenia remains unclear. The aim of the present study was to determine if patients with low P50-suppression (below 50%) report more perceptual anomalies. METHODS: Three groups were compared: twenty-nine schizophrenia patients with high P50-suppression (above 50% amplitude suppression), twenty-three schizophrenia patients with low P50-suppression (below 50%) and twenty-six healthy subjects. The Sensory Gating Inventory (SGI), a four-factor self-report questionnaire, was used to measure perceptual anomalies related to sensory gating. A comparison of demographic and clinical data was also carried out. RESULTS: Patients with low P50-suppression presented: i) significantly higher scores on the SGI (for the overall SGI score and for each of the 4 factors) and ii) significantly larger P50 amplitude at the second click, than both patients with high P50-suppression and healthy subjects. There were no group differences in the most of demographic and clinical data. DISCUSSION: The finding offers support for conceptual models wherein abnormal neurophysiologic responses to repetitive stimuli give rise to clinically relevant perceptions of being inundated and overwhelmed by external sensory stimuli. Further studies are needed to explore the contributions of clinical symptoms, medication and neuropsychological functions to the relationship between P50-suppression and the SGI, and the role of sensory "gating in" versus "gating out".