RESUMEN
This exploratory study aimed to investigate the relationship between interoceptive sensibility and quality of consciousness in individuals with insomnia disorder, in order to understand how the modulation of internal states may contribute to modifying the experience of consciousness during sleep difficulties. A total of 37 patients with insomnia disorder (mean age = 46.05 ± 18.16) and 41 healthy good sleepers (mean age = 50.2 ± 12.99) underwent a psychometric sleep and interoceptive sensibility assessment, using Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Multidimensional Assessment of Interoceptive Awareness (MAIA). Moreover, patients with insomnia disorder also completed a quality of consciousness evaluation, using the Phenomenology of Consciousness Inventory (PCI). Patients with insomnia disorder exhibited heightened interoceptive sensibility, particularly in noticing body sensations (p < 0.0001) and emotional awareness (p = 0.032), along with diminished abilities in attention regulation (p = 0.040), not-worrying (p = 0.001), and trusting (p = 0.002). Furthermore, correlations between interoceptive sensibility and multiple aspects of the consciousness state during the insomnia night were identified. Specifically, higher emotional awareness was linked to a 2.49-fold increase in the likelihood of subjectively experiencing altered consciousness states during insomnia. The study sheds light on the relationship between interoceptive sensibility and the subjective state of consciousness during insomnia, emphasising the importance of exploring and considering interoception as part of the therapeutic process for insomnia disorder. Given the exploratory nature of the study and the increased risk of type-I error from numerous correlations, the results should be interpreted with caution. Further research is needed to validate and confirm their robustness.
RESUMEN
This psychometric pilot study aims to evaluate a new multidimensional simple scale, named the nightmare severity index (NSI) - close to the existing insomnia (ISI) and hypersomnia (HSI) severity indexes. The NSI encompasses all main dimensions of nightmare disorder, evaluating four subdimensions: frequency, emotional impact, diurnal impact, and nocturnal impact of nightmares. The NSI was completed by a total of 102 patients. The majority of the population consisted of women (64%) and outpatient individuals (76%) diagnosed with mood disorders such as depression (31%) and bipolar disorder (41%). Comorbidity with post-traumatic stress disorder (PTSD) was prevalent (44%), and psychotropic medications were commonly used (47%). Internal validity analyses indicated that the NSI was well suited for exploratory factor analysis. All items demonstrated satisfactory correlations with the factors, and the questionnaire exhibited good internal consistency (Cronbach's alpha >0.7). Higher NSI scores were observed among individuals experiencing nightmare symptoms considering the DSM-5/ICSD-3 criteria. In summary, the NSI proves to be a promising and valuable tool for clinical practice, demonstrating good acceptability, internal validity, and the ability to assess nightmare severity.