Hallucinations in Older Adults: A Practical Review

Johanna C. Badcock; Frank Larøi; Karina Kamp; India Kelsall-Foreman; Romola S. Bucks; Michael Weinborn; Marieke Begemann; John-Paul Taylor; Daniel Collerton; John T. O'Brien; Mohamad El Haj; Dominic ffytch; Iris E Sommer

Disclosures

Schizophr Bull. 2020;46(6):1382-1395.

Abstract and Introduction

Abstract

Older adults experience hallucinations in a variety of social, physical, and mental health contexts. Not everyone is open about these experiences, as hallucinations are surrounded with stigma. Hence, hallucinatory experiences in older individuals are often under-recognized. They are also commonly misunderstood by service providers, suggesting that there is significant scope for improvement in the training and practice of professionals working with this age group. The aim of the present article is to increase knowledge about hallucinations in older adults and provide a practical resource for the health and aged-care workforce. Specifically, we provide a concise narrative review and critique of (1) workforce competency and training issues, (2) assessment tools, and (3) current treatments and management guidelines. We conclude with a brief summary including suggestions for service and training providers and future research.

Introduction

General Introduction

By 2050, it is estimated that 16% of people will be aged above 65 years, compared with 9% in 2019.^[1] Population aging is driving increased attention to the physical and mental health needs of older adults. Here, our focus is on hallucinations—given the wide range of health and aged-care service providers who encounter people with these experiences in their workplace. Hallucinations can be defined as "a perception-like experience with the clarity and impact of a true perception but without the external stimulation of the relevant sensory organ"^[2] (cf.^[3–5]), though this belies the difficulty in discerning the boundaries between normal and abnormal perception.^[6] Hallucinations need to be distinguished from illusions, which are perceptual experiences in which an external stimulus is misperceived or misinterpreted.^[2] In practice, hallucinations vary in content (eg, perception of people, animals, or objects), character (eg, frequency, emotional valence, location), duration (from seconds to chronically present), complexity (eg, perception of simple stimuli vs organized scenes or objects), and quality (eg, perceived reality, intrusiveness) and occur in all sensory modalities. The terms used to refer to hallucinations are equally diverse (see Table 1).

Hallucinations occur in people with sensory, neurological, medical, neurodegenerative, and psychological disorders^[7] as well as in those with no mental disorder at all.^[8–10] In healthy (nonclinical) samples, hallucination prevalence (across modalities) is lower in older than younger adults.^[8,9] In contrast, hallucinations are common in many clinical disorders associated with older age, with specific prevalence rates varying by condition, stage of illness, and symptom type. For example, visual hallucinations are common in dementia, Parkinson's disease, and in eye or visual pathway disease,^[11] while auditory hallucinations are prevalent with hearing loss.^[12] Similarly, multimodal visual, tactile, and auditory hallucinations tend to be more prominent in late- (between 40 and 60 years age) or very-late onset (60+ years) compared with early-onset schizophrenia.^[13] Across conditions, both similarities and differences have been reported,^[14,15] suggesting that the same assessments and treatments may not be appropriate for all presentations of hallucinations in older adults, which may be linked to the diversity of risk factors involved.^[16–19]

Whilst our understanding, assessment, and treatment of hallucinations in older adults have improved in the last decade, greater priority needs to be given to communicating these advances to clinicians so that clinical care can be grounded in the best available evidence. The International Consortium of Hallucinations Research Working Group on Hallucinations in Older Adults was set up to respond to this challenge. Accordingly, the purpose of this review is to highlight the key issues for the workforce caring for older adults with hallucinations; critically review current assessment tools, management guidelines, and treatment approaches for this population; and offer recommendations and resources to support best practice.

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Next Section

Abstract and Introduction
Workforce Competencies and Training Issues
Assessment Tools
Management and Treatment Approaches
Summary and Directions for Future Research
Resources
References

Table 1. Key Terms and Definitions of Hallucinations
Type of Hallucination	Related Terms	Definition
Bereavement hallucinations	• Grief hallucinations • Sensed presence • Experience of continued presence •Guardian angel experience	The experience of seeing, hearing, feeling, tasting, smelling, and/or sensing the presence of the deceased.
Charles Bonnet syndrome	• "Phantom vision" syndrome	Typically involves the experience of complex (ie, formed) visual hallucinations, in the context of visual loss, with insight that the experience is not real, in people with no marked cognitive dysfunction.
Complex hallucinations		The involuntary perception of an object or scene in the absence of a corresponding object/scene in the environment (ie, a formed perception whereby individual features have been linked or grouped into organized/connected wholes).
Hallucinations	• Private perceptions • Hearing voices (in the case of auditory hallucinations) • Seeing visions (in the case of visual hallucinations) • Unusual sensory experiences • Anomalous perceptions	"A sensory experience which occurs in the absence of corresponding external stimulation of the relevant sensory organ; has a sufficient sense of reality to resemble a veridical perception, over which the subject does not feel s/he has direct voluntary control and which occurs in the awake state."³ "an erroneous percept in the absence of identifiable stimuli."⁴ "[Perceiving] something involuntarily which, by all other measures, is not there."⁵
Hypnogogic and hypnopompic hallucinations	• Sleep-related hallucinations	Vivid, dreamlike experiences that occur on the borders of sleep These anomalous perceptions can occur when falling asleep (hypnogogic) or waking up (hypnopompic).
Multimodal hallucinations	• Compound hallucinations • Polymodal hallucinations • Polysensual hallucinations • Intersensorial hallucinations	Hallucinations that occur in more than one modality simultaneously, typically emanating from a single source. NB. Sometimes refers to hallucinations in different sensory modalities experienced serially.
Musical hallucinations	• Musical hallucinosis • Musical ear syndrome • Auditory Charles Bonnet syndrome • Oliver Sack's syndrome	The subjective experience of hearing music, or aspects of music, when none is being played. The perception of music can occur with or without voice and lyrics.
Olfactory hallucinations	• Phantosmia • Phantom smells	The detection of smells, when the corresponding odor is not present in the environment.
Passage hallucinations	• Sometimes referred to as "minor hallucinations"	The experience of a stimulus moving past the perceiver, in the periphery.
Presence hallucinations	• Feeling of presence • Sensed presence	The vivid sensation of the presence of another person or agent, usually close by, or just behind, the perceiver.
Simple hallucinations		The perception of unformed stimuli (eg, colored lines, high-pitched tones), when there are no such stimuli in the environment (ie, perceptions involving specific stimulus features rather than whole objects).
Tactile hallucinations	• Hallucinations of touch	The perception of a tactile stimulus that is not explained by the actions of another person or external object
Tinnitus	• Often called "ringing in the ears"	The perception of noises in one or both ears or inside the head, when no external sound source is present. Sounds often involve ringing, hissing, whistling, or buzzing but can be more complex (eg, a familiar tune).

Table 2. Recommendations for Training and Practice
Training and Practice Points	Examples
• Training should sensitize future professionals to the complex nature of hallucinations in psychotic and nonpsychotic disorders and raise awareness that hallucinations can, and do, occur in the absence of a diagnosis of mental illness or a need for care.	Training should aim to: 1) Provide knowledge about the multifactorial nature of hallucinations—individual features of the experience are complex (they can vary in content, emotional valence, frequency, duration, reality, location, distress, control, etc). 2) Increase understanding that hallucinations have multiple causal risk factors. Though not an exhaustive list, this includes: physical (eg, sensory loss/impairment, intoxication, drug abuse/withdrawal, inflammation), psychological (eg, trauma, bereavement, impaired cognition, disrupted sleep), and social (eg, loneliness and social isolation, discrimination) factors. 3) Challenge myths and stereotypes, eg, that hallucinations occur only in people with psychotic disorders, indicate a propensity to violence, or are untreatable. Know the facts: hallucinations occur not only in people with different diagnoses but also in the healthy population and often respond to treatment. 4) Challenge beliefs about the need for care—hallucinations are sometimes viewed as helpful and positive, are not always associated with distress or disruption to daily life, and may not need an intervention.
• Affirming, non-judgmental attitudes and behavior may encourage self-reporting and alleviate distress arising from hallucinations in older adults	The following approaches may be helpful: 1) Avoid trivializing or invalidating the patients' experience and how it makes them feel. 2) Ask the patient what their hallucinatory experience is like: everyone's experience is different. What (if anything) bothers them most? Communicate your understanding of what they have said back to them, to check you have understood them correctly. 3) Be patient, listen carefully, imagine being the person experiencing hallucinations—put yourself in their shoes. 4) Ask the patient if there are things that do or do not help them cope with their hallucinations.
• When enquiring about the experience of hallucinations with older adults and their families/carers use non-stigmatizing language and provide accurate information about the help that is available.	Non-stigmatizing ways of asking about hallucinations include: "People sometimes hear another person speak, while there is no one there. Also, music or other sounds can be heard, while it is unclear where this comes from. In the past 7 days, have you ever heard such voices, music, or other sounds?" "Over the past 7 days, have you seen things or images when there was no clear explanation for them? Or when no one else could see them? For example, people, animals, shadows, specific patterns, or objects?" "People sometimes smell the scent of smoke, when there is no fire. Another example is someone who smells flowers, while there are no flowers around. Have you ever had this experience in the past 7 days?" "People sometimes say they experience hearing and seeing things that others cannot see or hear both at the same time. Or they feel something/someone touching them they can also see, while others do not. If you feel comfortable, could you tell something about your experiences on this?"

Table 3. Quality Criteria for Assessment Tools
General: Applies to All Measurement Tools
Possesses good psychometric properties ^a	Content validity, internal consistency, construct validity, criterion validity, test-retest reliability, responsiveness (ie, ability to detect clinically important changes over time), floor and ceiling effects, cross-cultural validity, and interpretability (ie, the degree to which one can assign qualitative meaning to quantitative scores).
Clear and relevant instructions	State time period(s), ask participants to answer all the items, tell participants to exclude certain experiences or contexts (eg, "please do not include experiences where alcohol, cannabis, ecstasy, or other similar substances has been taken"), explain the response scale (eg, for 5-point response scales, inform participants to use the entire scale and not just the extreme points), and include "unsure/do not know" response possibility.
Items should be clear and understandable	eg, use a clear typeface and legible font size.
Specific: Applies to Measurement Tools for Hallucinations and in Older Populations
Evidence that it is appropriate and feasible for use with older adults	eg, adequate tool when used specifically with older adults, including those with sensory and cognitive limitations, or physical ill-health.
Psychometric properties are robust when used with older populations	eg, factor invariance between older and younger adults reported, items cover all possible types/modalities of hallucinations (content validity), test-retest reliability reported (to help clinicians calculating reliable change indices), and evidence of sensitivity to change the following treatment.
Captures hallucination-related experiences	eg, illusions, misperceptions, intrusive thoughts, flashbacks, daydreaming, etc. and able to distinguish these from hallucinations.
Assessment beyond presence/absence of hallucinations	eg, frequency, variation, location, associated other factors (eg, lighting, presence of other people, etc.), consistent or variable (is there temporal consistency?), and impact of the experiences on the person (practical, emotional, etc.)
Inclusion of additional dimensions associated with the experience	eg, whether or not the experience is associated with a certain degree of distress, conviction, preoccupation, etc.
Inclusion of (a) precise timeframe(s)	Specific timeframes (eg, "Have you had this experience in the past year?") and/or lifetime timeframes (eg, "Have you ever had this experience?"). Further, time periods assessed must be able to capture the new or recent onset of hallucinations vs hallucinations experienced throughout life.
Question addressing whether or not the individual has talked about the experience(s) with others	eg, "Have you discussed these experiences with your partner, carer, or doctor?"
Different versions of the measure available	Versions for: self, informant, clinician.
Question about the interpretability of the items	Whether or not the items were clear to the participant (and if not, which one(s) were unclear/difficult).
Inclusion of a brief screener	To identify people for whom a more detailed assessment may be warranted.
Introductory text states that the experiences have been shown to be quite common	However, this needs to be done carefully, so that these experiences are not further stigmatized.
Assessment beyond hallucinations	eg, hearing, vision, health, cognition, medication (and any other variables that may be considered causally related to the hallucinatory experience in question), to help distinguish between age-related sensory change and perceptual anomalies.

^aBased on Mokkink et al⁴⁵ and Terwee et al.⁴⁶

Table 4. Selected Examples of Assessment Tools for Hallucinations
Measure	Brief Description	Psychometric Properties in Older Adults	Strengths/Limitations
Self-report questionnaires
Launay-Slade Hallucinations Scale (LSHS).⁴⁷	Designed to assess hallucination predisposition in the general community. Original version has 12 items (Launay and Slade⁴⁷); an extended version has 16 items.⁴⁸ Items rated on a 5-point Likert scale: "0 = certainly does not apply to me," "1 = possibly does not apply to me," "2 = unsure," "3 = possibly applies to me," and "4 = certainly applies to me."	The E-LSHS has good validity and internal reliability (Cronbach's α = .87).^49,50 Factor analyses of the E-LSHS indicate a 4-factor solution measuring; (a) auditory and visual HLEs, (b) multisensory HLEs, (c) intrusive thoughts, and (d) vivid daydreams. Psychometric data in older adults are currently being examined. For the 3 LSHS auditory hallucinations items, Cronbach's α = .869 in adults 60+ yrs (data derived from reference⁸).	E-LSHS assesses a broad range of hallucinations in different modalities, including auditory, visual and olfactory, and items on hypnagogic and hypnopompic hallucinations and on sensed presence hallucinations.
Community Assessment of Psychic Experiences (CAPE).⁵¹	42-item measure—designed to assess lifetime psychotic-like experiences in the general population. It contains 3 subscales assessing positive, negative psychotic symptoms, and depressive symptoms and also includes ratings of distress.	Good validity and reliability, especially in younger samples. However, positive and negative subscales may be less reliable in older adults.⁵²	Provides comprehensive information about lifetime psychotic experiences. Available in 8 languages (from: https://cape42.homestead.com/index.html) Quite long.
Cardiff Anomalous Perceptions Scale (CAPS).^53,54	32-item measure—designed to assess anomalous perceptual experiences in the general community and clinical groups. Items scored YES or NO. If YES, items then rated for distress, intrusiveness, and frequency on a 5-point Likert scale.	Good validity in nonclinical (18–54 yrs) and clinical (psychotic disorder) groups (25–64 yrs). Good internal reliability (Cronbach α = .87) and test-retest reliability over 6 months (CAPS Total r = .77). Total scores uncorrelated with age.⁵³ Psychometric properties in older adults (50 yrs and above) currently being examined.	Uses neutral, everyday language. Designed to assess anomalous perceptual experiences, rather than general aspects of psychosis-like experiences. Validated in Spanish.⁵⁵ Freely available: https://osf.io/fm34z/ Quite long.
Psychosis and Hallucinations Questionnaire (PsycHQ).⁵⁶ Informant version available.⁵⁷	20-item measure—designed to assess hallucinations and other psychotic symptoms, attention, and sleep disturbance in Parkinson's Disease (PD). Frequency is rated on a 5-point Likert scale: Never, < 1 time per week, Weekly, Most days a week, Daily. Distress is rated on a 4-point Likert scale: None, Mild, Moderate, and Severe.	Good validity, good test-retest (intra-class correlation = 0.9), and internal reliability (Cronbach α = 0.9) in older patients with idiopathic PD.⁵⁶ (Note: average age of patients with positive response on PsycHQ 70.5 ± 8.5 yrs). Scores on Section I (core hallucinatory and psychotic symptoms) uncorrelated with age, disease duration, motor severity, or daily Levodopa equivalent dose.	Brief, typically < 10 mins. Developed in consultation with patients, caregivers, and clinicians and uses layman language. Questionnaire available from the authors upon request. Probes a broad spectrum of visual and nonvisual hallucinatory phenomena. Can help pick up PD hallucinations that may otherwise go missed by clinicians. Utility for assessing hallucinations in other disorders unclear.
Current Community Assessment of Psychic Experiences-15 (Current CAPE-15).⁵⁸	15-item version of the CAPE-42 measures positive "psychotic-like" experiences that have occurred in the last 3 months. Contains 3 subscales measuring persecutory ideation, bizarre experiences, and perceptual abnormalities, including ratings of distress.	Good validity and internal reliability in younger adults (Cronbach's α = .79)⁵⁸ Psychometric properties in older adults not evaluated.	Provides information about recent hallucinatory and psychotic-like experiences. Shortened version of the original 42-item CAPE questionnaire. Questionnaire freely available.⁵⁸
Multi-Modality Unusual Sensory Experiences Questionnaire (MUSEQ).⁵⁹	43-items assess unusual sensory experiences in 6 modalities: auditory, visual, olfactory, gustatory, bodily sensations, and sensed presence. Items rated on a 5-point Likert scale: 0 = Never, 1 = Hardly Ever, 2 = Rarely, 3 = Occasionally, and 4 = Frequently.	Acceptable test-retest reliability (r = .56– 0.77) and good internal reliability (Cronbach α = .77–88), and good construct and discriminant validity in nonclinical (mean = 27.75 and range 17–76 yrs) and clinical groups, including schizophrenia spectrum disorder and bipolar disorder (mean = 34.17 and range 18–67 yrs.). Psychometric properties in older adults not evaluated.	Provides information about sensory experiences in a number of modalities. Items designed to assess unusual sensory experiences according to a continuum structure (ie, most frequent to least frequent phenomena). Open access.⁵⁹ Quite long.
Clinician Administered
Psychotic Symptom Rating Scales (PSYRATS).⁶⁰	Structured interview for auditory hallucinations (and delusions) in patients with psychotic disorders. Symptoms in the last week are rated: 0 = no problem, 1 = minimal or occasional, 2 = minor to moderate, 3 = major, and 4 = maximum severity. Auditory hallucinations are also evaluated on frequency, duration, location, loudness, beliefs regarding origin of voices, negativity, distress, disruption, and controllability.	Good inter-rater and test-retest reliability, and good validity. Factor analysis shows a 4-factor solution measuring Distress, Frequency, Attribution, and Loudness.⁶¹	Provides a comprehensive, multidimensional assessment of auditory hallucinations. German, French, Indonesian, Malay, Portuguese, and Chinese translations available.
Auditory Hallucinations Rating Scale (AHRS).^62,63	Brief (7-items), structured clinical interview that measures the frequency, reality, loudness, number of voices, length, attentional salience, and distress of auditory hallucinations.	Adequate inter-rater and test-retest reliability and moderate internal consistency (Cronbach's α = .60).⁶² Psychometric properties in older adults not explored.	Provides a shorter alternative to the PSYRATS. Not widely used.
North East Visual Hallucinations Inventory (NEVHI).⁶⁴	Semi-structured interview designed to assess hallucinations in older adults with eye disease and cognitive impairment. Qualitative items rated on a 3-point Likert scale: 0 = never, 1 = sometimes, and 2 = always.	Good validity and good inter-rater and internal reliability (Cronbach α = .71).⁶⁵ Good convergent and divergent validity in older adults with PD (mean age 68.9 ± 7.6 yrs).⁶⁶	Includes brief screening questions. Examines both simple and complex visual hallucinations. Explores social, emotional, and behavioral impact of hallucinations.
Assessment of Phantosmia.⁶⁷	Single-item measure ("Have you in the last year experienced the so-called phantom smells?") scored 0 = "Never" to 4 = "Always." When present, fixed follow-up questions enquire about the type, intensity, duration, frequency, recency, and chronology of the experience.	Psychometric properties not formally assessed. However, phantosmia was not correlated with olfactory dysfunction, supporting the discriminant validity of objective and subjective olfactory measures. Prevalence of phantosmia reported to be uncorrelated with age in healthy individuals (60–90 yrs).	Brief administration time. Captures qualitative features of phantom smells. Some people may not fully understand the meaning of Phantosmia. Responses may be subject to bias.
Assessment of Phantosmia.⁶⁸	Standardized assessment with a single, negatively valenced item "Do you sometimes smell an unpleasant, bad, or burning odor when nothing is there? " Responses coded: Yes/No.	Psychometric properties not reported. For adults 40 yrs and above, an age-related decline in unpleasant, bad, or burning phantosmia observed for women but not men.	Assessment limited to olfactory modality. Positive or neutral phantom smells are not assessed. No information on intensity, duration, or periodicity.
Questionnaire for Psychotic Experiences (QPE).⁶⁹	50-item QPE designed to assess the presence, severity, and phenomenology of hallucinations (and delusions) across diagnostic groups.	Good validity and good test-retest reliability, inter-rater reliability, and internal consistency in patients with schizophrenia, schizoaffective disorder, bipolar disorder, and major depressive disorder and nonclinical participants (mean age: 40.3, 43.4, 32.1, 30.2, and 28.6 yrs, respectively). Psychometric properties in older adults/other diagnoses currently under examination.	Designed for use across a range of disorders. Available from: https://www.qpeinterview.com/en Quite long: 20–40mins administration time (but high completion rate, see reference⁶⁹). Requires training No specific comparisons of QPE between older and younger adults.