Fragmented sleep relates to hallucinations across perceptual modalities in the general population

Abstract

Although previous studies reported a link between sleep problems and the occurrence of hallucinations, more detailed information is needed to translate this association into clinical practice. This study investigates sleep quality and its relation to prevalence, type, content, and phenomenology of hallucinations, using an online survey in a large population sample (n = 10,299). Based on community-based cluster analysis, four groups could be distinguished that differed in terms of sleep quality. Our results confirm previous studies in showing that poor sleep is associated with the occurrence of hallucinations, and extend previous results on a number of aspects. First, we show that particularly fragmented sleep relates to the occurrence of hallucinations. Second, we show that this is the case for hallucinations across the auditory, visual, olfactory, and tactile domains. Third, our results show that fragmented sleep not only relates to the occurrence, but also to the content, frequency, duration, and associated distress of hallucinations. Finally, compared to poor sleep, good sleep quality is associated with hallucinations that are less negative and disruptive. We conclude that sleep hygiene measures could have a large positive impact on individuals whose fragmented sleep underlies the occurrence of bothersome hallucinations.

Figure 1

Sleep characteristics per group. Averages corresponding to the respective Pittsburgh sleep Quality Inventory domains (ranging from 0 to 3, where 0 is ‘good sleep quality’ and 3 is ‘poor sleep quality’), on which the cluster analysis was based. This figure was created using RStudio version 1.3.959.

Figure 2

Percentages of participants who experienced at least one hallucination in the past month calculated over all perceptual modalities (‘hallucinations’) and separately for each modality, where AH: auditory hallucinations; VH: visual hallucinations; OH: olfactory hallucinations; TH: tactile hallucinations. This figure was created using RStudio version 1.3.959.