The Cambridge Depersonalization Scale: a new instrument for the measurement of depersonalization

Existing self-rating scales to measure depersonalization either show dubious face validity or fail to address the phenomenological complexity of depersonalization. Based on a comprehensive study of the phenomenology of this condition, a new self-rating depersonalization questionnaire was constructed. The Cambridge Depersonalization Scale is meant to capture the frequency and duration of depersonalization symptoms over the 'last 6 months'. It has been tested on a sample of 35 patients with DSM-IV depersonalization disorder, 22 with anxiety disorders, and 20 with temporal lobe epilepsy. Scores were compared against clinical diagnoses (gold standard) and correlated with the depersonalization subscale of the Dissociation Experiences Scale (DES). The scale was able to differentiate patients with DSM-IV depersonalization disorder from the other groups, and showed specific correlations with the depersonalization subscale of the DES (r=0.80; P=0.0007). The scale also showed high internal consistency and good reliability (Cronbach alpha and split-half reliability were 0.89 and 0.92, respectively). The instrument can, therefore, be considered as valid and reliable, and can be profitably used in both clinical and neurobiological research.

Psychometric behaviour of BDI in Alzheimer's disease patients with depression

The psychometric properties of the Beck Depression Inventory (BDI) in subjects with Alzheimer's disease (AD) and depression have not been fully evaluated. Item endorsement patterns may be distorted by the presence of AD. This was tested by applying the BDI to a sample of 129 subjects with probable AD without depression and to 57 subjects with both probable AD and depression. It was found that the BDI under diagnoses depression in the context of AD. ROC curves for total BDI and cognitive and somatic items subsets showed low sensitivity and low areas under the curve indices. The results suggest that the BDI is not an ideal instrument to measure depression in AD. This may not result solely from the swing of the somatic items subset, but from other aspects which require further investigation.

The cognitive failures questionnaire in psychiatry

As a self-report questionnaire, the Cognitive Failures Questionnaire (CFQ) was originally devised to measure perception, memory, and motor lapses in daily life. CFQ scores have been found to correlate with some psychiatric symptoms associated with stress; hence, high scores on the CFQ are considered by some as an indicator of increased vulnerability to stress. Attempts to identify a stable factor structure for the CFQ have produced disparate results. However, there is a measure of agreement with regard to the presence of a "general cognitive" factor that includes loadings from most items and accounts for the lion's share of the variance. Not enough is known about the performance of the CFQ in clinical populations to use it as a measure of change. The current study sought to explore the performance of the CFQ in three groups of patients, organic (n = 209), mixed (n = 115), and functional (n = 322), and to identify correlations with measures of psychiatric morbidity (General Health Questionnaire [GHQ]), depression (Beck Depression Inventory [BDI]), and recognition memory (Signal Detection Memory Test). In the organic and functional samples, the CFQ score significantly correlated with the BDI and GHQ but not with the recognition memory measure. Three factors were found to be common to the organic and functional samples: cognitive, dissociation, and clumsiness. No characteristic pattern of CFQ item endorsement to differentiate between the organic and functional samples was found. Seven items of the CFQ performed badly because of ceiling or floor effects. The "negative" results reported herein are of relevance to researchers who may be planning to use the CFQ in clinical research. The CFQ remains a promising instrument, particularly on account of its "ecological" features, but far more investigation is needed before it is used as a standard measure in clinical practice.

Classifications in psychiatry: a conceptual history

BACKGROUND

Historical accounts of psychiatric classifications have hitherto been written in terms of a 'received view'. This contains two assumptions, that: (i) the activity of classifying is inherent to the human mind; and (ii) psychiatric 'phenomena' are stable natural objects.

OBJECTIVES

The aim of this article is to provide an outline of the evolution of psychiatric classifications from the perspective of conceptual history. This is defined as a theoretical and empirical inquiry into the principles, sortal techniques and contexts in which alienists carried out their task. It assumes that all psychiatric classifications are cultural products, and endeavours to answer the question of whether classificatory models imported from the natural sciences can be applied to man-made constructs (such as mental illness) definitionally based on 'personalised semantics'.

METHODS

Exemplars of classificatory activity are first mapped and contextualised. Then, it is suggested that in each historical period crafting classifications has been like playing a game of chess with each move being governed by rules. This is illustrated by offering an analysis of the 1860-1861 French debate on classification.

RESULTS AND CONCLUSIONS

(1) Medicine is not a contemplative but a modificatory activity and hence classifications are only valuable if they can release new information about the object classified. (2) It should not be inferred from the fact that psychiatric classifications are not working well (i.e. that they only behave as actuarial devices) that they must be given up. Conceptual work needs to continue to identify 'invariants' (i.e. stable elements that anchor classifications to 'nature'. (3) Because mental disorders are more than unstable behavioural epiphenomena wrapped around stable molecular changes, 'neurobiological' invariants may not do. Stability depends upon time frames. Furthermore, it is unlikely that gene-based classifications will ever be considered as classifications of mental disorders. For once, they would have low predictive power because of their lack of information about the defining codes of mental illness. 'Social' and 'psychological' invariants have problems of their own.

Flashbulb memories and other repetitive images: a psychiatric perspective

The term "flashbulb memory" was used by Brown and Kulik in 1977 to refer to the vivid recollections that humans may have of events considered to be of particular significance to the individual or group. These memories are described as having a photographic quality and as being accompanied by a detail-perfect apparel of contextual information (weather, background music, clothes worn, etc.) pertaining to the time and place where the event was first known. They may even evoke emotions similar to the ones felt upon hearing the news. It has been suggested that flashbulb memories are formed by the activity of an ancient brain mechanism evolved to capture emotional and cognitive information relevant to the survival of the individual or group. Some of the original assumptions made by Brown and Kulik have since been challenged, but the phenomenon in question remains an important area of research. However, the latter is often marred by the fact that flashbulb memories are studied as if they were unique psychological events without parallel in clinical practice. Psychiatrists, however, should consider flashbulb memories as being members of a broad family of experiences that include drug flashbacks, palinopsia, palinacusis, posttraumatic memories, and the vivid and haunting memories experienced by subjects with some forms of mental disorder (e.g., phobias, panic attacks, obsessional disorder, phantom-limb phenomena, and depressive melancholia). All of these experiences share clinical features such as paroxysmal repetition, sensory vividness, a capacity to trigger emotions, dysphoria, and a tendency for the rememberer to shift from the role of actor to that of observer and for the reminiscence to become organized in a stereotyped narrative. Some of these clinical phenomena are discussed, and the suggestion is made that seeking phenomenological and neurobiological common denominators to all of these experiences may be a superior research strategy versus studying flashbulb memories alone.

Confabulations: a conceptual history

Confabulations are inaccurate or false narratives purporting to convey information about world or self. It is the received view that they are uttered by subjects intent on "covering up" for a putative memory deficit. The epidemiology of confabulations is unknown. Speculated causes include amnesia, embarrassment, "frontal lobe" damage, a subtype of "personality", a dream-like event, and a disturbance of the self. Historical analysis shows that "confabulation" was constructed at the turn of the century as part of a network of concepts (e.g. delusion, fixed idea, etc.) meant to capture narratives with dubious content. This paper deals with the history of the construction of the word and concept of confabulation and with earlier recognitions of the behaviours that serve as their referent and puts forward a model based on historical data. Two phenomena are included under "confabulation": "untrue" utterances by subjects with memory impairment and "fantastic" utterances marshalled with conviction by subjects suffering from psychoses and no memory deficit. Under different disguises, the "covering up" or "gap filling" hypothesis is still going strong. Although superficially plausible, it poses problems in regards to the issue of "awareness of purpose": if full awareness is presumed then the semantics of the concept of "purpose" is severely stretched and confabulations cannot be differentiated from delusions.

Depersonalization: neurobiological perspectives

Depersonalization remains a fascinating and obscure clinical phenomenon. In addition to earlier Jacksonian neurobiological adumbrations, and conventional psychodynamic accounts, views started to be expressed in the 1930s that depersonalization might be a vestigial form of behavior, and since the 1960s that it might be a phenomenon related to the temporal lobe. Recent advances in the neurobiology of the limbic system, and the application of Geschwind's concept of disconnection in the corticolimbic system, have opened the possibility of developing testable models. This paper includes a review of these ideas and of the clinical features of depersonalization, particularly of its emotional changes, suggesting that they are important for the neurobiological understanding of depersonalization. It also draws attention to clinical similarities between the experiential narratives produced by patients suffering from depersonalization and those with corticolimbic disconnections. On the basis of this, a new model is proposed according to which the state of increased alertness observed in depersonalization results from an activation of prefrontal attentional systems (right dorsolateral prefrontal cortex) and reciprocal inhibition of the anterior cingulate, leading to experiences of "mind emptiness" and "indifference to pain" often seen in depersonalization. On the other hand, a left-sided prefrontal mechanism would inhibit the amygdala resulting in dampened autonomic output, hypoemotionality, and lack of emotional coloring that would in turn, be reported as feelings of "unreality or detachment."

The anhedonias: Clinical and neurobiological aspects

During the last 30 years there has been renewed clinical interest in the state of 'lack of pleasure' (anhedonia) seen in conditions such as schizophrenia and depression. In spite of some important work, confusion still remains about the term, behaviours and explanatory concepts pertaining to anhedonia. This paper reviews the clinical and basic scientific studies that throw light on this interesting clinical phenomenon and then presents a new model of anhedonia which can be tested empirically and should facilitate research in this field.

Depersonalization: a conceptual history

As with other clinical phenomena, the historical analysis of the term, concepts and behaviours involved in the construction of 'depersonalization' should provide researchers with an essential frame for its empirical study. Before the term was coined in 1898, and under a variety of names, behaviours typical of 'depersonalization' were reported by Esquirol, Zeller, Billod, and Griesinger. The word 'depersonnalisation, derived from a usage in Amiel's Journal intime, was first used in a technical sense by Ludovic Dugas. The new disorder has since been explained as resulting from pathological changes in the sensory system, memory, affect, body image and self-experience. During the 1930s, evolutionary views became popular, particularly in the work of Mayer-Gross. The unclear conceptual boundaries of depersonalization still invite confusion and often enough fragments of what used to be its core-behaviour are used to diagnose the disorder. Depersonalization has of late become subsumed under the dissociative disorders. The definitional instability of the latter, however, has caused further complications to the study of depersonalization. It is recommended that the term is used to refer only to the original core-behaviour as this has shown adequate stability.

The origins of psychosurgery: Shaw, Burckhardt and Moniz

The concepts and techniques involved in the origins of psychosurgery during the late nineteenth century are analyzed, particularly in the work of Claye Shaw and Gottlieb Burckhardt. It is shown that their views and therapeutic behaviour were guided by scientific, ethical and social warrants not dissimilar from those of today. The debate that followed their work can thus be considered as a trial run to that elicited by the work of Moniz. This paper focuses on the work of Shaw, Cripps, Tuke and Duncan for, until now, it has not featured in any history of psychosurgery. From the point of view of the history of science, their work is important, for it relates to the debate on brain localization, neuronal circuits and the neurobiological representation of mental illness that took place at the dawn of the twentieth century. Nothing is said on the history of psychosurgery subsequent to the work of Moniz.

[The scientific origin of ECT: a conceptual history]

This paper deals with the scientific origins of the electroconvulsive therapy, particularly between 1938 and 1945. The most interesting and imaginative research on ECT occurred in this period. An analysis of a host of social, moral and scientific factors to understand its history is offered, focusing on several european countries.

A conceptual and quantitative analysis of 178 historical cases of dysmorphophobia

The construction of the clinical category dysmorphophobia (now known as body dysmorphic disorder) resulted from the historical convergence of a neologism (coined by Enrico Morselli), a family of clinical concepts (already available during the late 19th century), and a specifiable behaviour (an 'attitude' towards part of the self and/or the body). The stability of such convergence has so far depended upon the epistemological capacity of the concepts involved and the social duration of the said attitude. This paper analyses the historical framework within which such convergence took place, and traces the history of dysmorphophobia in qualitative and quantitative terms. With regard to the latter, it compares cases reported before (139 subjects) and after (39 subjects) the publication of the DSM III criteria map. Patients in the former group were found to constitute a more heterogeneous group, and in the latter to have a better outcome. In the pre-DSM III group, differences were also found between delusional and non-delusional patients. The implications of these differences are discussed.

Pseudohallucinations: a conceptual history

The term 'pseudohallucination' is currently used to name imaginal experiences whose relationship to one another and to hallucinations 'proper' remains obscure. Clinicians, including specialists in psychopathology, disagree on how pseudohallucination must be defined and on its diagnostic role. Empirical research is unlikely to help as the term does not have a stable referent. Historical and conceptual analyses, on the other hand, are of great use to show how this untidy state of affairs has obtained. This paper includes a full account of the history of pseudohallucination and concludes that: (a) the problem has resulted from the fact that the history of the word, concept(s) and putative behaviour(s) failed to 'converge' (i.e. there never has been a time when the three components have formed a stable complex); (b) failure to converge has been caused by the fact that the concept of pseudohallucination is parasitical upon that of hallucination, and that the latter has proved to be far more unstable than what is usually recognized; (c) hence, pseudohallucination is a vicarious construct (i.e. one created by a temporary conceptual need, and which is not associated with a biological invariant); (d) pseudohallucination is used as the 'joker' in a poker game (i.e. made to take diagnostic values according to clinical need)- this has led to diagnostic complacency and retarded important decisions as to the nature and definition of hallucinations; and (e) the language of current descriptive psychopathology is not fine-grained enough to generate a stable frame for pseudohallucination. This suggests that its boundaries and usage will remain fuzzy and unbridled.

Recognition of hallucinations: a new multidimensional model and methodology

Both from the clinical and mathematical perspectives, symptom recognition has received less attention than disease recognition. To redress this balance, it is imperative that multidimensional models are constructed for each and all mental symptoms. This paper offers one such model for "hallucinations', and a set of prototypical data comparing the performance of pattern recognition techniques (cluster and discriminant analyses) and neural networks (Kohonen and backpropagation). It is concluded that multidimensional models are less wasteful of information than (current) categorial ones. Because of this and of the fact that symptom structure is likely to be "isomorphic' with the brain region where the corresponding signal is generated, it is recommended that multidimensional models are preferentially used in neurobiological research.

The enigma of pseudohallucinations: current meanings and usage

This study investigates the view of 2 samples of psychiatrists about pseudohallucinations (PH) and their perceived value in clinical practice. Among UK and Irish consultant psychiatrists, 87% expressed belief in PH, but 63% thought that the concept was confusing and only 58% thought PH were clinically useful. Recently appointed consultants were more positive about PH. One-third of respondents were sceptical: and even the more enthusiastic gave variable and inconsistent responses. Many psychiatrists do not value the concept of PH or do not use it. Those who do favour it use it inconsistently. The concept gives rise to much confusion, and is weak because it is defined negatively. It should be abandoned in favour of a more precise clinical approach to describing false perceptions.

The anhedonias: a conceptual history

BACKGROUND

The term and concept of 'anhedonia' refer to a group of clinical phenomena whose common denominator is the complaint of a putative incapacity to 'experience pleasure". Linked to disorders such as schizophrenia and depression, anhedonia remains difficult to define and measure.

METHOD

This paper explores the historical frames in which anhedonia was originally constructed; and is fully based on primary sources. It makes use of the 'conceptual method', i.e. it differentiates the history of the word from that of the behaviours and concepts involved.

RESULTS

Historical analysis shows that the boundaries of 'anhedonia' have been fuzzy since the time of Ribot, and that this has made it conceptually unstable. One reason for this instability pertains to the fact that from the start its definition has been parasitical upon the (itself evolving) concept of 'pleasure'. Another that it is defined negatively, i.e. as a reduction or abolition in a putative unitary function. Yet another, that there is little evidence that anhedonia itself is a unitary phenomenon.

CONCLUSIONS

It is concluded that at this stage it might be advisable to refer to the concept in the plural (the anhedonias); that a definition should be formulated that it is less dependent upon the ongoing concept of pleasure; and that far more empirical research is needed to find out whether anhedonia is more than a final common pathway.

Insight in clinical psychiatry. A new model

Recent interest in insight in psychiatry has resulted in studies focusing on correlations between insight and variables such as severity of psychopathology, neuropsychological impairments, and magnetic resonance imaging. However, there has been relatively little exploration of the concept of insight itself as a basis of empirical research. This paper examines the concept of insight, differentiating this from the phenomenon of insight, and proposes that insight is a construct that needs to be considered from the perspective of the patient, of the clinician, and of their interaction. A new hierarchical model of insight construction is described, closely linked to symptom formation, and mechanisms are suggested to explain insight structure in relation to the different ways symptoms arise. The relationship between insight and symptom structure and disease suggests that the phenomenon of insight will vary in relation to different diseases. This in turn suggests that insight assessments should be modified according to the individual disease.

Abulia and impulsiveness revisited: a conceptual history

Historical analysis suggests that the decline and fall of the will was due not to any major piece of empirical work demonstrating that the concept was unsound but to general changes in philosophical fashion, and to the temporary influence of the anti-mentalistic tenets of behaviorism and the anti-volitional assumptions of psychoanalysis. Clinical disorders like abulia and impulsiveness share conceptual features that 19th-century alienists captured well in their clinical category of disorder of the will. Current accounts, which include semi-explanatory concepts such as "drive", "motivation" or frontal lobe "executive" are not conceptually better than the old notion of will nor are they superior as correlational variables for neurobiological studies. It is suggested that the will, updated according to modern work in the philosophy of action, be re-adopted as a research category in current psychiatry.

Insight in clinical psychiatry revisited

Current research on insight in psychiatry has focused on exploring the relationship between insight and other clinical variables such as severity of psychopathology, compliance with medication, general outcome, and, more recently, neuropsychological impairments. However, the studies yield divergent and inconsistent results, and consequently the role of insight in relation to such variables remains unclear. We review here recent studies in this area and suggest that one reason for variability in the results relates to confusion surrounding the term "insight." It is argued here that more conceptual work is needed to help clarify the meaning of insight before further empirical research is undertaken. Some of the conceptual issues are raised, and it is suggested that the concept of insight is first differentiated from the phenomenon of insight (its clinical representation) to facilitate a more structured and systematic approach to the examination of insight in clinical practice.

The predelusional state: a conceptual history

The predelusional state (PDS) is defined as the set of psychopathologic events preceding the crystallization of delusions, and includes strange cognitions, moods, conations, and motor acts that may be fleeting and defy description. This review exclusively deals with the historic aspects of PDS. It is noted that during PDS the patient is expected to report experiences for which, on account of their novelty, he may not even have a name. Thus, it is quite likely that according to culture and personal codes and to the conceptual brief of the interviewer, similar experiences might be reported as depersonalization, bodily sensations, dysphoria, changes in perception of reality or time, dissolution of "ego boundaries," etc. It is therefore not surprising that since the 19th century, PDS has been considered a disorder of cognition, emotions, volition, and consciousness.

Autonomic failure, depression and anxiety in Parkinson's disease

BACKGROUND

The study tested the hypothesis that subjects with Parkinson's disease (PD) have more autonomic complaints and more attenuation of autonomic reflexes than controls, and that both clusters of variables are related to the presence of anxiety and depression.

METHOD

Thirty-two subjects and 32 healthy controls matched by age and sex were prospectively compared on psychiatric, cognitive and autonomic tests.

RESULTS

'Autonomic' symptoms: were more frequent in PD patients than in healthy controls; were not related to age or changes in autonomic reflexes; were significantly associated with depression and anxiety (medication was not relevant to the association); and did not correlate with motor symptoms.

CONCLUSIONS

The diagnosis of anxiety and depression in some PD subjects is likely to be a behavioural phenocopy caused by autonomic failure. This explains why antidepressant medication is often unhelpful in PD subjects diagnosed as depressed.

Cotard's delusion or syndrome?: a conceptual history

This report offers an account of the historical construction of Cotard's syndrome showing that by délire des négations the French author meant a subtype of depressive illness. Subsequent debate led first to the belief that it was just a collection of symptoms associated with agitated depression (anxious melancholia) or general paralysis, and later to the view that it might after all constitute a separate entity. At the present moment, and impervious to the fact that the French term délire means far more than "delusion," some authors use Cotard's syndrome to refer to the belief of being dead and suggest that such a delusion might have a specific brain location. From the clinical and evolutionary perspective, it is unclear why a delusion should merit, simply because of its "nihilistic" content, a special brain location or presage chronicity. It is suggested here that before neurobiologic speculation starts, efforts should be made to map out the clinical features and correlations of the délire des négations.

The Cambridge Neurological Inventory: a clinical instrument for assessment of soft neurological signs in psychiatric patients

A schedule (the Cambridge Neurological Inventory) has been constructed for standardized neurological assessment of psychiatric patients. Normative data and data resulting from its application to a group of patients with schizophrenia are reported. The instrument is comprehensive, reliable, and easy to administer. In conjunction with other forms of clinical assessment, it may be useful for identifying soft neurological signs and other patterns of neurological impairment relevant to neurobiological localization and prognosis in schizophrenia and other psychiatric disorders.

Déjà vu in France during the 19th century: a conceptual history

The feeling of déjà vu features as prominently in the creative as in the clinical literature. However, its meaning and mechanisms remain unclear, and it is posited here that this has partially resulted from the way in which this symptom was originally conceptualized. During the late 19th century, medical opinion seemed agreed that déjà vu was a disorder of memory (a paramnesia). However, its study was obfuscated by an overemphasis on its secondary features (e.g., "feeling of conviction," "fleetingness") and by "parapsychological" interpretations. Around the turn of the century, the problem was compounded by the development of narrow models of memory (inspired by association psychology) that left no room for the descriptive complexities of déjà vu. Consequently, it soon became (and has remained) a "symptom without a psychological function." French psychological writers played a crucial role in the conceptualization of déjà vu and this report presents a detailed history of their contribution.

Cotard's syndrome: analysis of 100 cases

In 1880, Jules Cotard reported a clinical state he believed was a new type of agitated melancholia. A statistical analysis has been carried out of 100 cases of Cotard's syndrome to determine how this clinical concept has fared since its inception. In terms of clinical profile, no difference was found between men and women or between underlying diagnostic categories; age seemed to increase the likelihood of developing délire des négations. Depression was reported in 89% of subjects; the most common nihilistic delusions concerned the body (86%) and existence (69%). Anxiety (65%) and guilt (63%) were also common, followed by hypochondriacal delusions (58%) and delusions of immortality (55). An exploratory factor analysis extracted 3 factors: psychotic depression, Cotard type I and Cotard type II. The psychotic depression factor included patients with melancholia and few nihilistic delusions. Cotard type 1 patients, on the other hand, showed no loadings for depression or other disease and are likely to constitute a pure Cotard syndrome whose nosology may be closer to the delusional than the affective disorders. Type II patients showed anxiety, depression and auditory hallucinations and constitute a mixed group. This new grouping cuts across the more traditional view and may have therapeutic implications. Authors, in general, have considered délire des négations as a syndrome rather than a new disease and do not seem to support the view that the completeness of the syndrome is a function of presence or severity of depression. The view that délire des négations refers only to the delusion of being dead has also carried little favour as its likely to waste information.

Mental symptoms: are they similar phenomena? The problem of symptom heterogeneity

Psychiatric symptoms are heterogeneous and differ in origin, structure and clinical expression. These differences are frequently ignored both clinically and in research. Thus, patients may be described as being anxious or as having delusions, with little realisation that different aspects of the structure of symptoms are being depicted. Neglect of differences in structure between symptoms has also naturally resulted in the neglect of differences in structure between superficially 'same' symptoms. A model is offered here which provides a means of classifying heterogeneity on the basis of five levels of clinical differentiation which, in turn, carries implications for underlying symptom structure. At the 1st level, symptoms can be differentiated in terms of the conventional category 'form' but which is in fact a composite of criteria. At the 2nd level, symptoms may be separated by differences in diagnosis which may alter structure; it is suggested that one way of capturing these is to assess the qualitative dimensions of the form. At the 3rd level, differentiation can occur on the basis of sensory modality, and, using hallucinations as an illustration, it has been shown that this is a weak and confused criterion. At the 4th level, symptoms can be differentiated on the basis of abstract criteria, often of historical origin, for which there is little empirical evidence. At the 5th level, the main criterion is difference in content. That not all symptoms will be susceptible to a fivefold analysis reinforces the argument that symptoms are structurally different and that these differences have psychometric and research implications.

Autoscopic phenomena

BACKGROUND

Autoscopy is defined here as a visual experience where the subject sees an image of him/herself in external space, viewed from within his/her own physical body. This paper reviews the literature both historically and conceptually, and includes a quantitative study of accumulated cases.

METHOD

Cases published since 1935 and meeting the above definition for autoscopy (n = 53) were included, together with three personally-observed patients. A clinical protocol was completed for each case, including information about the autoscopic image. Cases were compared using non-parametric statistics on dichotomised variables.

RESULTS

There were 38 men and 18 women, with a mean age of 39.5 years (range 13-78). Of the subjects, 33 (59%) had a neurological illness, most frequently epilepsy (18 cases). Right and left sided lesions were equally represented. Psychiatric disorder was often present (33 cases, 59%), most commonly delirium, depression or psychosis. The features of the images seen were diverse, but speaking images were associated with younger age, male sex, psychotic illness, longer duration of image, and hypnagogic/hypnopompic experiences.

CONCLUSIONS

Autoscopy may arise from a convergence of several variables, including gender, personality factors, neurological and/or psychiatric disease, exhaustion and dissociation, whose interaction may override the normal inhibition of temporal lobe activity. A cognitive neuropsychological hypothesis is proposed, together with avenues for future research.

The notion of a unitary psychosis: a conceptual history

'Unitary psychosis' is the collective name for a set of disparate doctrines whose common denominator is the view that there is only one form of psychosis and that its diverse clinical presentations can be explained in terms of endogenous and exogenous factors. This paper examines the history of these doctrines since the eighteenth century in the work of their main sponsors and extricates their conceptual assumptions. It is shown that the nature of the debate between 'unitarians' and those who believed in the existence of separate diseases has changed throughout time, and that to these changes national differences have been important. Earlier discussions made use of conceptual and ontological argument; latter ones of clinical analysis; and the latest debate, that occurred during the 1970s, over-relied on statistical techniques and genetic analysis. The outcome of this long debate remains inconclusive.

Delusional misidentifications: facts and fancies

The term 'delusional misidentification syndromes' (DMS) encompasses disparate clinical phenomena. This lack of agreement has resulted in a proliferation of definitions and classifications and impeded progress in aetiological research. It is suggested here that one reason for such confusion lies in current overemphasis on the content of such phenomena and a consequent neglect of their form. Research directed at clarifying the protean forms in which misidentifications manifest themselves should help to delineate more stable clinical phenomena and identify causal mechanisms.

Recognising psychiatric symptoms. Relevance to the diagnostic process

Current overemphasis on nosological diagnosis has led to a neglect of the process of symptom recognition. There is evidence, however, that the perception of the symptom alone does not guarantee symptom ascertainment since a decision-making component is also involved. To achieve the latter, additional information must be provided by the contextual cues implicit in the ongoing diagnostic hypothesis. Current diagnostic systems, however, still assume a two-stage model according to which symptom and disease recognition are independent cognitive events. This paper suggests that this model is inadequate and that descriptive psychopathology is not transparent. It then describes a neural network simulation to make various aspects of the problem explicit. This takes into account the multidimensional and probabilistic aspects of symptom recognition and is, from this point of view, superior to traditional algorithmic models. It also has the capacity to represent the different cognitive styles involved in symptom recognition.