A Review of Multimodal Hallucinations

Categorization, Assessment, Theoretical Perspectives, and Clinical Recommendations


Schizophr Bull. 2021;47(1):237-248. 

In This Article

Assessment of MMHs

In order to better understand the phenomenology and prevalence of MMHs, it is important to have appropriate, valid, and reliable assessment tools that go beyond the measurement of unimodal experiences in the main sensory domains. To review the available measures fit for this purpose, published measures of MMHs across clinical and nonclinical populations were compared and summarized in Table 2. For measures to be considered for review, they needed to include 3 or more modalities of hallucinations, be published, and used by researchers other than the developers and have evidence of their reliability and validity.

Overall, although several of the scales examined can be used to detect serial MMHs, only 4 out of 16 have items that specifically assess simultaneous MMHs, with most focusing on one modality (eg, visual domain in the NEVHI).

To enable researchers and clinicians to reliably and validly detect both serial and simultaneous MMHs, scales need to include:

  • assessments of the dimensional categories discussed;

  • items detecting delirium (acute state characterized by attentional impairments, cognitive dysfunction, and fluctuating awareness of the surroundings[39]) as this can be common in neurodegenerative disease patients[40] and their experiences might be mistaken for MMHs but be delirium episodes;[41]

  • items assessing the presence of sleep disorders and incubus experiences in sleep paralysis as these can be linked to multisensory vivid experiences that might again be confused as MMHs (particularly in neurodegenerative disorders;[42]

  • items evaluating experiences beyond the common 5 sensory modalities and what the relationship between them is.