Pseudohallucinations: A Pseudoconcept? A Review of the Validity of the Concept, Related to Associate Symptomatology Roy van der Zwaard and Machiel A. Polak “Pseudohallucination” is a concept used in the classification of nonpsychotic perceptual disorders. This report describes the history of the concept and investigates whether pseudohallucinations pseudohallucinations can be differentiated tiate d from relat related ed psyc psychop hopatho athologi logical cal symp symptoms toms,, such as hallucinations, re-experiencing, and dissociative phenomena. We performed a literature review, which shows that pseudohallucinations pseudohallucinations and related symptoms symp toms have low construct construct validity and are, ac-
cordingly, clinically ambiguous. Most likely, pseudohallucina hallu cination tions s are plac placed ed on an overl overlappi apping ng cont contininuum of symptomato symptomatology logy that includes perceptual disorders, orde rs, re-ex re-experi perienci encing, ng, (dis (dissoc sociativ iative) e) imag imagery, ery, and normal thought and memory processes. Recommendations datio ns are made regarding regarding the spec specifica ification tion of dimensions of this continuum. The term “nonpsychotic hallucinations” hallucinat ions” is preferred over “pseudo “pseudohallucinat hallucination.” ion.” Copyright © 2001 by W.B. Saunders Company
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In 1996, Berrios and Dening 6 published a conceptual history on this subject. However, in this review, we will mainly investigate the discriminant validity of the concept. Therefore, we will try to differentia diffe rentiate te pseud pseudohallu ohallucinati cinations ons on phenom phenomeenological nologi cal and descr descriptive iptive criteria from other experien per iences ces in whi which ch an ade adequa quate, te, act actual ual ext extern ernal al stimulus is absent, such as in hallucinations, imagination, inatio n, obses obsessions sions,, re-exp re-experienc eriences, es, and disso dissociaciative phenomena. Next, we will discuss the consequences for the validity and use of the concept of pseudohallucinations. Etiological and pathogenetic explanations of pseudohallucinations, such as from psychodynami psycho dynamics, cs, neurob neurobiology iology,, and inform informationationprocessing theories, are outside the scope of this review.
LTHOUGH PSEUDOHALLUCINATION is a commonly common ly used descriptive descriptive entity in clinic clinical al practice and forms an integral part of the standard mental status examination, a straightforward operational definition of the construct is missing. Dening and Berrios1 showed that a majority of psychiatrists considered the notion to be confusing and clinically not useful. Psychiatrists who did use the concept, predominantly did so inconsistently. The aim ai m of th this is re revi view ew is to in inve vest stig igat atee wh whet ethe herr pseudohallucinations can be operationalized and, if so, can make a contribution to a more systematic mental status examination by increasing the comprehensiven prehen siveness, ess, interc interchangea hangeability bility,, and reliab reliability ility of psychiatric observations. Semantically, “pseudohallucination” can be considered a contradictio in terminis (a false perceptual disorder), which might partia par tially lly acc accoun ountt for the con confus fusing ing sta status tus of the concept. conce pt. As yet, pseud pseudohallu ohallucinat cinations ions have been described in the literature as (1) perceptual disorders without sensory vividness, 2 (2) hallucinations with intact reality-testing and insight,3 and (3) isolated hallucinations (without additional psychopathol th olog ogy) y) th that at do no nott fit in an any y ot othe herr di diag agno nost stic ic 4 category. Furthe Furthermore, rmore, it is unclear whether there is (dis)continuity with hallucinations, or whether it is a form of (normal) imagination, 5 volunt voluntarily arily or not.
METHOD A Medline search from 1986 to current using “pseudohallucinations” as a key word provided us with 12 articles. ClinPsyc does not include “pseudohallucinations” as a keyword. Subsequently, both databases were searched for the keyword “hallucinations, cinat ions,”” succe successiv ssively ely in comb combinati ination on with “diss “dissociat ociation,” ion,” “obsessio “obse ssions,” ns,” “imag “imagery ery,” ,” “post “post-trau -traumatic matic stres stresss diso disorder rder”” (PTSD), “re-experiences,” “memory,” and “self-talk.” In addition, salient references from obtained articles were followed up on. Phenomenological descriptive standard textbooks (Bleuler, Kraepelin Krae pelin,, Jaspe Jaspers rs and, much newer: Kaplan & Sado Sadock ck and DSM-IV) were screened for the same keywords. All literature was descriptive and/or conceptual in nature, with the empirical study by Sedman7 as the only exception.
RESULTS From the Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands. Current address: Rijngeest Group of Mental Health, Noordwijk, The Netherlands. Address reprint requests to Roy van der Zwaard, MD, Anton Constandsestraat 36, 1097 HX Amsterdam, The Netherlands. Copyright © 2000 by W.B. Saunders Company 0010-440X/00/4201-0008$10.00/0 doi:10.1053/comp.2001.19752 42
Genesis of the Concept The expression “pseudohallucination” was first introduced by Hagen8 in 1868, in his German writing Zur Theorie der Halluzinationen (“On Theory of Hallucinations”), and elaborated by Kandinsky 9 in 1885, as the need was felt to distinguish perceptual phenomena in psychotic syndromes from other
Comprehensive Psychiatry, Vol. 42, No. 1 ( January/Februa January/February), ry), 2001: pp 42-50
PSEUDOHALLUCINATIONS: A PSEUDOCONCEPT?
clinic clin ical al pi pict ctur ures es.. To de deri rive ve at a de defin finit itio ion n of pseudo pse udohal halluc lucina inatio tions, ns, the they y dre drew w hea heavil vily y on the debate about hallucinations held in France over the previous 20 years, which resulted in the consensus that, beside besidess “path “pathologic ological” al” halluc hallucinatio inations, ns, “psychic/physio chic/p hysiologic/ logic/mystic mystic”” halluc hallucinatio inations ns also existed. Absence of insight and external localization of the experiences contributed to the pathological charac cha racter ter of hal halluc lucina ination tionss as the they y wer weree see seen n in schizophrenia (“primary madness”). Goldstein and Jaspers continued the conceptual discussion at the start of this century. Goldstein10 proposed that the notion of pseudohallucinations was only justified when reality testing remained intact. Bleuler 11 followed Goldstein in stating: “Perceptions with complete sensory clearness and normal localization of which the deceptive character is noticed, are called pseudohallu pseud ohallucinati cinations.” ons.” Jasp Jaspers ers5 critic criticised ised Goldstein ste in sha sharpl rply y and rej reject ected ed rea realit lity y tes testin ting g as the crucia cru ciall var variab iable, le, as it refl reflect ected ed the app apprai raisal sal of a pe perc rcep epti tion on ra rath ther er th than an an in intr trins insic ic as aspe pect ct of the per percep ceptio tion. n. In Jas Jasper pers’ s’ vie view w, dis discrim crimina inating ting pseudohallucinations from hallucinations is purely a matter of Sinnlichkeit (sensory vividness, “freshness”) nes s”) and the alm almost ost unt untran ransla slatab table le not notion ion of Leibhaftigkeit, by which is meant literally form of palpability palpab ility (“corporeality”): (“corporeality”): “When we take normal rep repres resent entati ations ons (Vorstellungen) and add to them more and more characteristics of perception such as independence of volition, clarity, and detail, but not ‘corpo ‘corporealit reality y,’ we arrive at pseud pseudohalohallucinations. lucina tions.”” Jaspe Jaspers rs assig assigned ned pseud pseudohallu ohallucinacinations to imagin imagination, ation, representation representation,, and thought disorders “which are separated by an abyss” from perceptual disorders. Furthermore, these representations were considered to possess a spontaneous qual qu alit ity y, wh whic ich h is to sa say y th that at th they ey co coul uld d no nott be produc pro duced ed or alt altere ered d by wil will. l. Sub Subseq sequen uentt aut author horss followed Goldstein’s or Jaspers’ concepts, or combined bin ed the them, m, as did Tayl aylor or,,3 who postul postulated ated that there are two types of pseudohallucinations: “perceived” (hallucinations with insight) and “imaged” (vivid intern internal al imagin imagination) ation).. Sedma Sedman, n,7 in the only empirical empiric al study on pseud pseudohallu ohallucinat cinations, ions, examined 72 patients and found that both imagery (internal ter nal loc locali alizat zation ion,, low sen sensor sory y viv vividn idness ess)) and pseudo pse udohal halluc lucina inatio tions ns (se (senso nsory ry per percep ceptio tion, n, wit with h intact int act rea realit lity y tes testin ting) g) wer weree ass associ ociate ated d wit with h “un “un-stable personality” personality” rather than psych psychotic otic illnes illness. s. The Pre Presen sentt Sta State te Exam Examina ination tion (PSE (PSE))12 defined
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pseudo pseu doha hall lluc ucin inat atio ions ns as vo voic ices es co comi ming ng fro from m within the mind, as opposed to originating from the outside world. Never before had this criterion been defined so explicitly, although it may have had its root ro otss in th thee wo work rk of Se Sedm dman an..7,13 Th Thee id idea ea of pseudo pse udohal halluc lucina inatio tions ns is sli slight ghtly ly mod modifie ified d in the PSE successor, the Schedules For Clinical Assessment in Neuro Neuropsychi psychiatry atry (SCAN)14: “internal hallucina luc inatio tions ns (whi (which ch may be cal called led pse pseudo udohal hallulucinati cin ations ons,, alt althou hough gh thi thiss phr phrase ase can als also o be use used d differently) are inner voices or images which are as concrete and vivid as hallucinations. They are experienced within the mind (i.e., inside the head), cann ca nnot ot be ev evok oked ed or ch chan ange ged, d, wi with th or wi with thou outt insight present. The assumption of a clear distinction between between the types (in (inter ternal nal or ext extern ernal) al) is somewhat artificial.” The Composite International Diagnostic Interview (CIDI)15 does not include the pseudohallucination concept. As a result, an entire generation of psychiatrists (to this day) was influenced by the PSE definition in their understanding of pseudohallucinations. Kaplan and Sadock 16 assigned the concept to the class of perceptual disorders: “perceptions experienced as coming from within the mind,” as well as “hallucinations whose validity the patient doubts,” for which they recommend the phrase “partial hallucinations, hallucinations,”” analo analo-gous to “parti “partial al delus delusions.” ions.” In the recent literature, the concept of pseud pseudohallu ohallucinat cinations ions is rarely mentioned. tion ed. Since 198 1986, 6, in add additi ition on to thr three ee rev review iew 6,17 articles, only on ly ni nine ne ar arti ticl cles es in incl clud udee ps pseu eudo do-halluc hal lucina inatio tions, ns, in wid widely ely dif differ ferent ent den denota otatio tions. ns. Pseudohallucinations as a result of partial sensory deprivation (e.g., visual or auditory impairment) or neurol neu rologi ogical cal dis disorde orders rs (e. (e.g., g., epi epilep lepsy sy and migraine) receive increasing attention. Disorders of the periph peripheral eral sensory syste systems ms typica typically lly produc producee ill-formed, ill-for med, simpl simplee perce perceptions ptions (e.g., photo photopsias psias:: stripe str ipes, s, sta stars, rs, col colors ors). ). Som Someti etimes mes the ter term m is reserved for drug-induced psychosis or for the unusual phenomenon that radiosignals are conducted by de dent ntal al fil filli ling ngss or sh shra rapn pnel el fra fragm gmen ents ts in th thee 2 patient’s skull.
Differentiation From Other Psychopathological Symptoms To the extent that there is any consensus about the definition of pseudohallucinations, it appears to be focused on two qualities: (1) pseudohallucinations are perceptions, experienced within the mind (with (wit h or wit withou houtt sen sensor sory y viv vividn idness ess); ); and and/or /or (2)
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VAN DER ZWAARD AND POLAK
pseudohallucinations are considered hallucinations with intact reality testin testing. g. Can pseud pseudohallu ohallucinacinations be differentiated from other psychopathological symptoms on the basis of these qualities? In other words: what can we say about its discriminant validi validity? ty?
Differentiation From Hallucinations (T (Table able 1) Pseudohallucinations often are defined in negatively tiv ely:: as exp experi erienc ences es tha thatt res resemb emble le but are not 1 identi ide ntical cal to hal halluc lucina inatio tions. ns. Th Thee de defin finit itio ion n of pseudohallu pseud ohallucinati cinations ons is thus interd interdepende ependent nt with the val validit idity y and reli reliabi ability lity of the hal halluc lucina inatio tions ns concept. In general, hallucinations are considered expe ex peri rien ence cess th that at (1 (1)) oc occu curr in the ab abse senc ncee of a corresponding sensory stimulus, (2) occur involuntarily, and (3) are considered real by the hallucinator. From a phenomenological perspective, hallucinations lucina tions cannot be discri discriminate minated d from normal perceptions percep tions,, i.e., “real “real”” perce perceptions ptions and halluc hallucinaina18 tions can have ident identical ical charac characterist teristics. ics. These characterist charac teristics ics includ includee vividn vividness, ess, comple complexity xity,, involuntarines volunt ariness, s, and extern external al local localizatio ization. n.19 In th thee general population, 10% to 25% ever experience hallucinations, mostly of an auditory or visual nature. Familiar halluc hallucinatio inations ns are hypnag hypnagogic ogic and hypnapomp hypnap omp exper experience iences, s, and audito auditory ry halluc hallucinainations tio ns in norm normal al gri grief ef rea reacti ctions ons..20 Consequently, hallucinations cannot be considered a sign of psychopathology chopat hology per se; they are relatively nonspecific. Even though certain forms of hallucinations occur more often in certain conditions (i.e., as a result of alcohol or drugs abuse), these forms cannot be considered pathognomonic.18 Seventy-five percent of schizophrenic patients ever experience Table Tabl e 1.
Characte Char acteristi ristics cs of Hallucinatio Hallucination n
Variable
Hallucinations
Auditive Visual Haptic Olfactory Gustatory Localization Vividness Reality testing Cont Co ntin inui uity ty ov over er ti time me Func Fu ncti tion onal al re resu sult lt Control Second Sec ondary ary del delusi usions ons Cue-triggering Other
Often Sometimes Rarely Rarely Rarely Often external From lifelike to as-if character Impaired Yes Ye s Ofte Of ten n an anxi xiet etyy-pr prov ovok okin ing g No Often Oft en Sometimes Often bizarre dreamlike
(functional) hallucinations. (functional) hallucinations. Most often these are auditory hallucinations that take the form of voices speaking to each other or addressing the patient in an often devaluating, devaluating, imperative, or comme commenting nting fashion. The voices are often familiar to the patient and can vary in number, gender, and localization (inside or outside the head). Interference with processing of other auditory stimuli is possible. The voices are often anxiety-provoki anxiety-provoking ng and can trigge triggerr secondary delusions. Stress and anxiety can result in an increase of hallucinations. 21 The content of hallucinations is often emotionally charged. Over the last 10 years, much progress has been made by the neurosciences (neuropsychology, neurochemistry rochem istry,, neuroa neuroanatomy natomy)) in unders understandin tanding g the development of hallucinations. However, neuroscientific hypotheses remain quite speculative 22-24 and fall outside the scope of this report. To investigate thee va th vali lidi dity ty of pu purp rpor orte ted d ch char arac acte teri rist stic icss of pseudohallu pseud ohallucinati cinations, ons, we will try to diffe differentia rentiate te them from qualitative parameters of hallucinations. Internal localization of voices does not discriminate between pseudohallucinations and hallucinations. Pen Pennin nings gs and Rom Romme me25 compa compared red three groups of people hearing voices: schizophrenics, patients patien ts suffe suffering ring from disso dissociativ ciativee disord disorders, ers, and nonpat non patien ients ts (i. (i.e., e., wit withou houtt psy psychi chiatr atric ic cla classi ssifica fica-tion). All three groups reported hearing voices insidee the sid their ir hea head, d, as wel welll as orig origina inating ting from the outside world, and voices were predominantly considere sid ered d ego egodys dyston tonic. ic. The hal halluc lucina inatio tions ns wer weree mainly mai nly exp experi erienc enced ed in sec second ond per person son sin singul gular ar across the three groups. Commenting Commenting voices dominated slightly in schiz schizophren ophrenia. ia. In sum, these formal characteristics did not adequately discriminate between patients and nonpatients, which was consistent siste nt with previous finding findings. s.26 In oth other er wor words, ds, internal localization of voices does not appear to be an exclus exclusive ive propert property y of pseud pseudohallu ohallucinat cinations. ions. The as-if character of many hallucinations does not discriminate from pseudohallucinations. Particularly ticula rly “mild psychotic symptoms” can exhibi exhibitt an as-if character; “It is as if something is crunching in my brain, like a persistent buzzing.” While reality testing remains initially intact, it may disappear app ear whe when n the exp experi erienc ences es bec become ome ine inesca scapp27 able. In similar fashion, the fading of hallucinationss duri tion during ng whi which ch the qua qualit lity y of rea realit lity y tes testing ting increases does not change the past or present psychopathological state.
PSEUDOHALLUCINATIONS: A PSEUDOCONCEPT?
Hallucinations with intact reality testing are Ther eree ar aree pseudohallucinations by definition. Th multiple states during which experiences share all featur fea tures es intr intrins insic ic to hal halluc lucina inatio tions ns but in whi which ch reality testing remains intact. An example is the auditory audito ry hallu hallucinati cination on during normal grief reactions in which the voice of the deceased is heard, often with external localization and a high level of sensory vividness.20 Other examples include well functioning normals hearing voices25 and hallucination nat ionss in the Cha Charle rless Bon Bonnet net syn syndro drome me (CB (CBS). S). The latter consists of non–anxiety-provoking, complex visual perceptions (e.g., tiny animals or figures) ure s) in the elderly elderly wit with h sen sensor sory y viv vividn idness ess and insigh ins ight, t, in the abs absenc encee of pri primar mary y or sec second ondary ary 28 delusions. The etiology etiology of CBS is unc unclea lear, r, although a combination of factors seems likely. All hallucinations mentioned above could be considered ere d pse pseudo udohal halluc lucina ination tionss in vie view w of the uni unimmpaired pai red rea reality lity testing. testing. Perh Perhaps aps it is mor moree app approropria pr iate te to la labe bell th thes esee ex expe perie rienc nces es as “i “iso sola late ted, d, nonpsychotic hallucinations.” DSM-IV descriptions do not adequately discriminate pseud pseudohalluc ohallucination inationss fro from m halluc hallucinatio inations. ns. 29 In DSM-IV, pseud pseudohallu ohallucinati cination on is mentio mentioned ned only once, in descri describing bing conversion: conversion: “hallu “hallucinacinations (‘pseudohallucinations’) generally occur with intact insight in the absence of psychotic symptoms, often involve more than one sensory modality, and have a naive, fantastic or childish content. They are often psychologically meaningful.” This is no nott at al alll sp spec ecific ific to ps pseu eudo doha hall lluc ucin inat atio ions ns:: schizophren schiz ophrenic ic or organ organic/dru ic/drug-indu g-induced ced psych psychosis osis can produce simultaneous hallucinations of more than one modality, and be characterized by naive, fantastic, or childish content. In these conditions, hallucinatio halluc inations ns can be kaleis kaleiscopica copical, l, change from onee co on comp mple lex x fo form rm to an anot othe herr (e (e.g .g., ., a do dolp lphi hin n changing into a submarine), change within a single image (e.g., a man’s head gradually swells in size and changes from pink to blue, becomes a balloon and an d flo float atss aw away ay)) or ca can n be re repe peti titi tive ve (o (one ne to toy y soldier is duplicating and becomes a whole army), etc.30 Overa Overall, ll, pseudo pseudohallu hallucinati cinations ons canno cannott be adequately differentiated from hallucinations, partly because becau se the latter is too inconsistently inconsistently and broadl broadly y defined. To pre preven ventt unn unnece ecessa ssary ry con confus fusion ion:: an “il “illulu5 sion” can be defined as an inaccurate interpretation of real external sensory stimuli (i.e., a bath-
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robe is, tran transie sientl ntly y hel held d for a bur burgla glar), r), while a “delusional percept” is an expression of a thought disorder and refers to the experience during which normal perceptions are invested with a delusional meaning (e.g., moonlight interpreted as the glowing of the devils’ eye). Both phenomena are easily discriminated from pseudohallucinations, as there is no external sensory stimulus in the latter.
Differentiation From Obsessions and Imagery (Table 2) Pseudohallucinati Pseudohallu cinations ons cannot be differ differentiat entiated ed from certain forms of imagery and obsessional imagery. In imagery, repeated imaging of an ob ject (i.e., to call images to mind of an apple or a piece of music) results in similar but not identical images. Only the most typical features are kept in memory.31 Both sensory vividness and internal coherencee (i.e., continuity herenc continuity over time) are absen absent. t. The expe ex peri rien ence cess ar aree us usua uall lly y vo volu lunt ntar ary y an and d ca can n be stopped or changed at any time. In 1981, Taylor 3 postulated the concept of “imaged pseudohallucinations,” by which he meant vivid, internal, involuntary imagination, imagination, quite similar to Jasp Jaspers’ ers’ description script ion early this centur century: y: “dres “dressed sed up image imagery ry,” ,” lacking the corporeality of hallucinations. To illustrate, the phenomenon of a melody stuck in one’s mind min d me meet etss al alll cr crit iter eria ia of the co conc ncep eptt of (“ (“im im--
Table Tabl e 2.
Characte Char acteristi ristics cs of Obsessions Obsessions and Imagery
Variable
Auditive Visual Haptic Olfactory Gustatory Internal localization External localization Vividness Reality testing Continuity over time Functi Fun ction onal al res result ults s
Control Secondary delusions Other
Obsessional Imagery
Fantasy and Imagery
Yes Yes ? ? ? Yes
Yes Yes Yes No? No? Yes
No
No
Lifelike Intact No
Low Intact No
AnxietyAnxiet yprovoking, wish-fulfilling No/temporary Possibility
Supportive, wish-fulfilling Ye Y es No
Often sexual, or aggressive
Also: daydreams
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VAN DER ZWAARD AND POLAK
aged”) pseudohallucinations, for it is involuntary, internal, characterised by intact reality testing, and has an as-if character. Another example is obsessional imagery, a specific form of obsession. Obsessions sessi ons are recurr recurrent, ent, persi persistent stent ideas, though thoughts, ts, impulses, impuls es, or images that are egodys egodystonic, tonic, which the individual is able to recognize as a product of his/ hi s/he herr ow own n mi mind nd..29 Obs Obsess ession ional al ima imager gery y (the compulsion to call images to mind of mutilation, sexual acts, and practices of war) also has a striking in g si simi mila larit rity y to su supp ppos osed ed ch char arac acte teris ristic ticss of pseudohallu pseud ohallucinati cinations. ons. Reali Reality ty testin testing g remain remainss intact, tac t, but in con contra trast st to nor normal mal ima imager gery y, sen sensor sory y vividness is high and the experiences are almost involuntarily.32 However, the term “pseudohallucination”” is confus nation confusing: ing: obviously the phenom phenomenon enon relatess to a thought or imager relate imagery y process, rather than a perceptual disorder, under which pseudohallucinations are classified. Overall, it becomes apparent that there likely exist smooth transitions between thinking, imagery, fantasy, memory and perceptual disorders.
Differentiation From Re-experiences and Dissociative Phenomena Pseudohallucinations cannot be clearly discriminated from re-experiences, although the latter are always alw ays bas based ed on act actual ual pri prior or eve events nts (T (Tabl ablee 3). Re-experiences are defined as recurrent memories thatt can con tha consis sistt of per percep ception tions, s, hal halluc lucina inatio tions, ns, imagination, thoughts, dreams, or flashbacks. Reexperiences not only occur in PTSD patients, but also als o as a pos posttra ttrauma umatic tic sym sympto ptom m in dis dissoc sociat iative ive 29 disorders. A trauma can be so overwhelming overwhelming that Table 3.
Characteristics of Re-experiences Re-experiences
Variable
Re-experiences
Auditive Visual Haptic Olfactory Gustatory Inte In terrna nall loc ocal aliz izat atio ion n Exte Ex tern rnal al lo loc cal aliiza zati tio on Vividness Reality testing Con Co nti tin nui uitty ove verr ti tim me Func Fu ncti tion onal al re resu sult lts s Control Seco Se cond ndar ary y de delu lusi sion ons s Trauma Cue-triggering
Yes Yes Yes Yes Yes Yes No Lifelike to faint/distorted Intact Oft fte en Anxi An xiet etyy-pr prov ovok okin ing g No Poss Po ssib ibil ilit ity y Yes Yes
normal information processing has been affected. Memori Mem ories es of the tra trauma uma are sto stored red imp implic licitly itly as sens se nsor ory y fr frag agme ment ntss on only ly.. Mo Most st of th thee tim timee th thee trauma will be “remembered” “remembered” as flashback experiences, or as visual, olfactory, auditory, or affective “imprints.”33 Activation (triggering) of these dissociated memories results in perceptions and imagess tha age thatt rec receiv eivee vir virtua tually lly no ela elabor borati ation on from memo me mory ry,, an and d ar aree of a “n “non on-p -pas astt an and d no nonn-se self” lf” 34 nature. Re-experiences can be seen as vivid sensory experiences related to anxiety-inducing past events, with unclear insight. With decreasing external stimuli demands (e.g., during relaxa relaxation, tion, retirement) re-experiences tend to increase. In spite of the their ir viv vivaci acity ty,, re-e re-expe xperie rience ncess are not rel reliab iable le memorie mem ories. s. In fac fact, t, rere-exp experi erienc ences es hav havee more in common with lifeli lifelike ke memories than with halluci35 nations. nation s. Horowi Horowitz tz propos proposed ed an exten extensive sive spectrum of re-experiencing that ranges from faint impressions press ions to vivid, detailed, detailed, intrus intrusive, ive, repetitive memoriess and pseud memorie pseudohallu ohallucinat cinations ions to halluc hallucinainations. Important dimensions of this spectrum are the degree of vividness and reality testing. Pseudohallu Pseud ohallucinati cinations ons cannot be differ differentiat entiated ed from perceptual distortions occurring in dissociative pathology (Table 4). Various US studies on dissociative disorders show that those disorders are often accompanied with hallucinations in all sensory modalities, especially in dissociative identity disorder disord er (DID).36 On Onee th thir ird d to th thre reee fo four urth thss of patients with DID experience hallucinations, many have been previously diagnosed with schizophrenia.. The nia These se hal halluc lucina inatio tions ns are ofte often n aud audito itory ry and mainly experienced as internalized, usually coming from fro m wi with thin in th thee he head ad an and d he hear ard d as di dist stin inct ctiv ivee voices with its own age, gender and personal attributes, e.g., imperative voices, or voices arguing with wit h eac each h oth other er abo about ut the pat patien ients’ ts’ behavio behavior. r. In some instances, the voices may be supportive or soothi soo thing. ng. Typi ypical cally ly,, tho those se voi voices ces sta start rt in ear early ly childhood and remain present in later life; they are never absent for a prolonged time. These experience en cess sh shou ould ld no nott be co cons nsid ider ered ed as an is isol olat ated ed symptom; they are always associated with a cluster of dissociative symptoms, e.g., amnestic episodes, depersonali depers onalization zation,, ident identity ity fragme fragmentatio ntation, n, and a high degree of hypnot hypnotizabil izability ity.. Visual halluc hallucinainations are often nocturnal and less frequent. Those auditory and visual experiences seem to have low sensory vividness and are typically related to the
PSEUDOHALLUCINATIONS: A PSEUDOCONCEPT?
Table 4. Chara Characteri cteristics stics of Dissociat Dissociation ion Variable
Auditive Visual Internal localization External localization Vividness Real Re alit ity y te tes sti tin ng Continuity over time Functiona Func tionall resu results lts Control CueCu e-tr trig igge geri ring ng Other
Dissociation
Yes Yes Often Sometimes Lifelike to faint Intac Inta ct Yes Anxiety-provo Anxiety-p rovoking/ king/ supportive Seldom Some So meti time mes s Often congruent with personal past or functioning; childhood start; part of other dissociative symptoms
patient’s functioning or to past trauma, and it is believed that they can also be a representation of an “alter “alternate nate person personality ality.” .”15,29,37 Althou Although gh hardly evidence-based, the experiences seem to be consistent siste nt with the conce concept pt of pseudo pseudohallu hallucinati cinations ons and might be the same phenomenon that was formerly known as “hysterical or dissociative psychosis.” However, in our opinion, “psychosis” would be too strong a label, while “imagery” would not capture its severity. Borderline Border line person personality ality patie patients nts can exper experience ience short sho rt lap lapses ses of rea realit lity y tes testin ting g (e. (e.g., g., hou hours). rs). The audito aud itory ry and vis visual ual hal halluc lucina inatio tions ns app appear ear to be manife man ifesta station tionss of the int intens ensee anx anxiet iety y res resulti ulting ng from fro m th thee pa pati tien ents ts’’ in inab abil ilit ity y to co cope pe wi with th th thei eirr stresses, stres ses, partic particularly ularly in unstru unstructured ctured situat situations. ions.38 The hallucinations in those states should be called “transient hallucinations,” which suit them better than pseud pseudohallu ohallucinati cinations ons or microp micropsycho sychosis, sis, as the experiences share all characteristics of hallucinations, including loss of insight. However, later studies39 did not con confirm firm the view tha thatt pat patien ients ts with borderline personality disorder characteristically cal ly exp experi erienc encee bri brief ef psy psycho chotic tic epi episod sodes es only only.. Many Man y pat patien ients ts had sym sympto ptoms ms las lastin ting g wee weeks ks to months. CONCLUSIONS AND RECOMMENDATIONS
In sum, it is evident that pseudohallucinations cannot can not be rea readil dily y dis distin tingui guishe shed d fro from m hal halluc lucina ina-tions, imagery, re-experiencing, or dissociative ex-
47
periences. Both pseudohallucinations and hallucinations can have an as-if character, coexist with intact reality testing, be experienced internally and involuntarily involu ntarily,, and can be explai explained ned psych psychologiologically. It remains unclear whether pseudohallucinationss can be as viv tion vivid id as hal halluc lucina inatio tions. ns. Ima Imager gery y shares most of the properties with the former concepts,, but sensory vividness and continuity in time cepts is typically absent. Re-experiences can be distinguished from pseudohallucinations by the presence of past, traumatic events, cue-triggering, and intact reality testing. Pseudohallucination (characterized by insig insight, ht, involu involuntarin ntariness, ess, and intern internal al locali localizazation)) see tion seems ms to fit bes bestt wit with h vis visual ual and aud audito itory ry experiences seen among patients with DID. Evidently den tly,, the there re are exp experi erienc ences es wit with h int intact act rea realit lity y testing that fall between the broad classes of hallucination and imagery. For some of these experiences enc es cha charac racter terize ized d by inta intact ct rea reality lity tes testin ting, g, it seems more appropriate to use the term “nonpsychotic hallu hallucinati cinations” ons” than pseudo pseudohallu hallucinati cinations. ons. Except for realit reality y testin testing, g, these experi experiences ences can share all featu features res with tradit traditional ional hallucinations. hallucinations. The con concep ceptt of non nonpsy psycho chotic tic hal halluc lucina inatio tions ns has two adv advant antage ages: s: it avo avoids ids the den denomi ominat nation ion of pseudohallucinations as “unreal” or “less severe,” and it breaks the automatic link between hallucination nat ionss and psy psycho chosis sis.. We rec recomme ommend nd to sub sub-divide div ide pse pseudo udohal halluc lucina inatio tions ns into the foll followi owing ng catego cat egorie ries: s: (1) non nonpsy psycho chotic tic hal halluc lucina inatio tions: ns: (a) isolated nonpsychotic hallucinations, (b) vivid internal imagery; (2) partial hallucinations; and (3) transient transi ent halluc hallucinatio inations. ns. Nonps Nonpsychoti ychoticc halluc hallucinainations would include isolated hallucinations as seen among amo ng nor normal malss dur during ing gri grief ef rea reacti ctions ons,,20 among normal functioning individuals with auditory hallucinations, or among patients suffering from sensory sor y dep depriva rivatio tion, n, e.g e.g., ., in CBS CBS..28 Experi Experiences ences in dissociative pathology are likely continuous with vivid internal imagery along Jaspers’ lines. Fading halluc hal lucina inatio tions ns wit with h inc increa reasin sing g ins insight ight are bet better ter considered consid ered partial halluc hallucinatio inations. ns. Short lapses of reality testing in patients with borderline personality pathology should be called “transient hallucinations.” It will be evident that not all experiences can be readil rea dily y cat catego egoriz rized. ed. Cla Classi ssifica ficatio tion n may ben benefit efit from spe specif cifyin ying g the foll followi owing ng for formal mal asp aspect ectss of percep per ceptio tion, n, re-e re-expe xperie rienci ncing, ng, and ima imagin ginati ation on (Spitzer,17 modified): modality (i.e., visual, audi-
48
VAN DER ZWAARD AND POLAK
tory, haptic, olfactory, gustatory), complexity (i.e., simple v comple complex/forme x/formed d exper experiences iences), ), locali localizazation (i.e., extern external al v intern internal), al), degree of senso sensory ry vividness (e.g., bright, lifelike, contextual, compelling), degree of realit reality y testin testing, g, degree of voluntary control, contro l, modula modulation tion over time (continuity), (continuity), connection with thought disorders ([secondary] delusions, obsessions), and connection with trauma and dissociation. Tabl ablee 5 sho shows ws how the these se factors factors can help in discriminati discri minating ng (albe (albeit it somew somewhat hat artific artificially) ially) between twe en the dif differ ferent ent form formss of psy psycho chopat pathol hology ogy.. Since all factors can all be present or absent in varyin var ying g deg degree rees, s, it is impo impossi ssible ble to mak makee sha sharp rp distinctions between all experiences; in other words: discriminant validity of these psychopathological symptoms is low. Most likely, fluid transitions exist, resulting resulting in a continuum from hallucinations hallucinations (a perceptual disorder) to pseudohallucinations (in its most extreme form a thought disorder) and dissociativ cia tivee mem memory ory (re (re-ex -exper perien iences ces)) to nor normal mal pro pro-4,35,39,40 cesses ces ses of mem memory ory,, tho though ughtt and fan fantas tasy y,
which language cannot adequately articulate. The continuum might best be conceptualised as overlapping lappin g circle circless (simil (similar ar to Venn diagra diagram), m), rathe ratherr than a single line. Presumably, various symptoms on thi thiss con contin tinuum uum can coe coexis xist. t. The con continu tinuum um hypothesis still leaves many questions unanswered. It remains unclear why in some disorders experiences can shift on the continuum (hallucinations in schizophren schiz ophrenia ia can be locali localized zed both interna internally lly and externally, can be vivid or faint), while they seem fixed in other syndromes (hallucinations in CBS are always localized externally, with varying degrees gre es of viv vividn idness ess). ). And why is it tha thatt pse pseudo udo-halluc hal lucina inatio tions ns are mai mainly nly ref referr erred ed to vis vision ion and auditi aud ition, on, but rar rarely ely (if eve ever) r) to the other sense modalities? modali ties? Perhaps the continuum exists only at a descriptive level, but is not tenable at the neurobiological level. The implications of this continuum hypoth hyp othesi esiss for our neu neurob robiolo iologic gical, al, eti etiolo ologic gical, al, syndromal, and therapeutic body of thought have not been investigated yet. For example, does vivid imagery imager y predis predispose pose to halluc hallucinatio inations? ns? Are there
Table 5. Factors in the Specification Specification of Processes of Perception, Perception, Re-experiencing, Re-experiencing, and Imagery Imagery Hallucinations*
Auditive Visual Haptic Olfactory Gustatory Internal localization External localization Vividness Reality testing Continuity over time Functi Fun ctiona onall res result ults s Control Secondary delusions Trauma Cue-triggering Other
Nonpsychotic Hallucinations§
Obsessional Imagery
Often Sometimes Rarely Rarely Rarely Sometimes Often From lifelike to as-if character Impaired¶ Yes
Yes Yes Yes† ‡ ‡ Often Sometimes Lifelike to faint
Yes Yes ‡ ‡ ‡ Yes No Lifelike
Intact Yes
Intact No
Often anx Often anxiet ietyyprovoking No Often
Anxiety-provoking/ supportive Seldom No
Anxiety-provoking/ wish-fulfilling No/temporary Possibility
Sometimes Often bizarre, dreamlike
Sometimes Often congruent with personal past or functioning
‡ Often sexual, perverse or aggressive
* Includes transient hallucinations. † Phantom limb pain, for example. ‡ No evidence in literature. § Includes isolated hallucinations and vivid internal imagery. ¶ With the exception of partial hallucination hallucinations. s.
R ee-experiences
Fantasy and Imagery
Yes Yes Yes Yes Yes Yes No Lifelike to faint/ distorted Intact Often
Yes Yes Yes No‡ No‡ Yes No Low
AnxietyAnxi ety-prov provoking oking
Supportive, Supportiv e, wish-fulfilling Yes No
No Possibility Yes Yes Always related to trauma
Intact No
‡ Also: daydreams
PSEUDOHALLUCINATIONS: A PSEUDOCONCEPT?
49
diseases with pathognomonic qualitative aspects of perception, imagery, or thinking? (How) do nonpsychotic hallucinations respond to neuroleptics?* Although there is an unfortunate lack of data, a polyvalent concept as pseudohallucinations should only be part of a mental status examination when it receives further specification. Otherwise, the concept cannot be adequately discriminated from other psychopatho psych opathologica logicall notion notions, s, and has few, if any any,, evidence-based consequences for daily practice. To
* It is known from case reports that nonpsychotic hallucinations in dissociative disorders and in Charles Bonnet syndrome do not respond to neuroleptics.28,37
date, the con date, concep cept’ t’ss mai main n con contri tribut bution ion is to giv givee clinicians the opportunity to doubt the “realness” of hal halluc lucina inatio tions ns tha thatt do not com comfor fortab tably ly fit our 6 diagnostic categories. Nevertheless, the simple dichotomy chotom y “hall “hallucinat ucinations” ions” versus “pseu “pseudohal dohallucilucinations” results in an unjustified simplification of reality, leaving too many “shades of gray” unnoticed. ACKNOWLEDGMENT The authors wish to thank Professor B.P.R. Gersons, M.D., Ph.D., and D.H. Linszen M.D., Ph.D. for their critical comments on earlier versions of this manuscript, and J.H. Kamphuis, Ph.D. for his editorial contribution.
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