Categorical perception of familiarity: Evidence for a hyper-familiarity in schizophrenia

a b s t r a c t Familiarity is a crucial aspect of recognition that may be perturbed in schizophrenia patients (SZP) and may lead to delusional disorders. However, there are no existing guidelines on how to assess and treat familiarity disorders in schizophrenia. Some experimental studies have investigated familiarity processing in SZP but have produced inconsistent results, which are likely a result of methodological issues. Moreover, these studies only assessed whether familiarity processing is preserved or impaired in SZP, but not the tendency of SZP to consider unfamiliar stimuli to be familiar. By using a familiarity continuum task based on the existence of the categorical perception effect, the objective of this study was to determine whether SZP present hyper-or hypo-familiarity. To this purpose, 15 SZP and 15 healthy subjects (HS) were presented with facial stimuli, which consisted of picture morphs of unfamiliar faces and faces that were personally familiar to the participants. The percentage of the familiar face contained in the morph ranged from 5 to 95%. The participants were asked to press a button when they felt familiar with the face that was presented. The main results revealed a higher percentage of familiarity responses for SZP compared with HS from the stimuli with low levels of familiarity in the morph and a lower familiarity threshold, suggesting a hyper-familiarity disorder in SZP. Moreover, the intensity of this "hyper-familiarity" was correlated with positive symptoms. This finding clearly suggests the need for a more systematic integration of an assessment of familiarity processing in schizophrenia symptoms assessments

Relationship between childhood physical abuse and clinical severity of treatment-resistant depression in a geriatric population

Introduction: We assessed the correlation between childhood maltreatment (CM) and severity of depression in an elderly unipolar Treatment-Resistant Depression (TRD) sample. Methods: Patients were enrolled from a longitudinal cohort (FACE-DR) of the French Network of Expert TRD Centres. Results: Our sample included 96 patients (33% of the overall cohort) aged 60 years or above, with a mean age of 67.2 (SD = 5.7). The majority of the patients were female (62.5%). The Montgomery and Asberg Depression Rating Scale (MADRS) and Quick Inventory Depression Scale-Self Report (QIDS-SR) mean scores were high, 28.2 (SD = 7.49) [MADRS score range: 0–60; moderate severity≥20, high severity≥35] and 16.5 (SD = 4.94) [IDS-SR score range: 0–27; moderate severity≥11, high severity≥16], respectively. Mean self-esteem scores were 22.47 (SD = 6.26) [range 0–30]. In an age- and sex-adjusted model, we found a positive correlation between childhood trauma (CTQ scores) and depressive symptom severity [MADRS (β = 0.274; p = 0.07) and QIDS-SR (β = 0.302; p = 0.005) scores]. We detected a statistically significant correlation between physical abuse and depressive symptom severity [MADRS (β = 0.304; p = 0.03) and QIDS-SR (β = 0.362; p = 0.005) scores]. We did not observe any significant correlation between other types of trauma and depressive symptom severity. We showed that self-esteem (Rosenberg scale) mediated the effect of physical abuse (PA) on the intensity of depressive symptoms [MADRS: b = 0.318, 95% BCa C.I. [0.07, 0.62]; QIDS-SR: b = 0.177, 95% BCa C.I. [0.04, 0.37]]. Preacher & Kelly’s Kappa Squared values of 19.1% (k2 = 0.191) and 16% (k2 = 0.16), respectively for the two scales, indicate a moderate effect. Conclusion: To our knowledge, this is the first study conducted in a geriatric TRD population documenting an association between childhood trauma (mainly relating to PA) and the intensity of depressive symptoms

Study of familiarity in patients with schizophrenia, impact on the risk of violent behaviour

La familiarité correspond au sentiment d’avoir déjà rencontré une personne, un lieu, un objet, indépendamment de la capacité à restituer le contexte initiale de cette rencontre. Le sentiment de familiarité peut ainsi être perçu même si le stimulus dont il s’agit n’est pas clairement identifié. Les travaux menés sur la familiarité s’intègrent dans des domaines de recherche assez variables, les principales recherches ayant été réalisées dans le cadre plus général de l’étude de la mémoire de reconnaissance, et dans le cadre de l’étude de la reconnaissance des visages.Des troubles du sentiment de familiarité peuvent avoir des conséquences importantes sur les interactions sociales. De tels troubles ont notamment été rapportés chez des patients présentant des troubles neurologiques (comme la maladie d’Alzheimer) ou psychiatriques (comme la schizophrénie). En fonction de leur sévérité, ces troubles peuvent être à l’origine de troubles graves du comportement, jusqu’à la réalisation de gestes de violence sévères, comme décrits par exemple dans certains troubles délirants de familiarité associés à la schizophrénie.Les objectifs de ce travail de thèse sont donc de clarifier les méthodes d’évaluation de la familiarité afin d’en préciser les corrélats neuronaux, puis chez les patients souffrant de schizophrénie, d’étudier le sentiment de familiarité, et d’évaluer les conséquences des altérations de ce sentiment, principalement en termes de risque de violence.Plusieurs études ont été menées afin de répondre à ces objectifs. Nous avons tout d’abord réalisé différentes méta-analyses des données d’imagerie de la littérature, selon les méthodes d’évaluation employées, pour déterminer avec précision les réseaux cérébraux impliqués dans le traitement de stimuli familiers. Nous avons ensuite développé une méthode d’étude du sentiment de familiarité permettant de quantifier le sentiment de familiarité, et adaptée aux patients présentant des troubles cognitifs, comme les patients souffrants de schizophrénie. L’évaluation de l’association entre les troubles de la familiarité et le risque de violence a été réalisée à partir d’une revue de littérature des descriptions de cas de gestes violents réalisés dans des contextes de troubles de familiarité pour mettre en évidence les facteurs de risque de violence communs à ces situations cliniques. Afin d’objectiver ces données, nous avons également effectué une évaluation clinique systématique des troubles du sentiment de familiarité des patients souffrant de schizophrénie. Cette étude a été réalisée en population carcérale pour permettre une évaluation au sein d’une population particulièrement à risque de violence.A travers les travaux présentés dans cette thèse, nous avons abordé l’étude de la familiarité, du sujet sain au patient de psychiatrie, de l’étude des mécanismes cérébraux à celle des conséquences comportementales. Les résultats de ces travaux confirment l’importance à accorder à l’étude du sentiment de familiarité, et à celle de ses troubles, en particulier dans les populations de patients psychiatriques.Familiarity is the feeling that provides the experience that a person, an object, a place, has been previously encountered independent of any recollection of the associated details. Thus, the feeling of familiarity may be reached even when the stimulus is not clearly recognized. Familiarity has been studied using various approaches. Major research has been conducted in the context of recognition memory and faces recognition.Familiarity disorders have been described as a failure of affective judgment capable of strongly impacting social interactions. They are notably present in some neurological disorders (such as in Alzheimer’s disease) and psychiatric disorders (such as in schizophrenia). Depending on the symptoms severity, these disorders may lead to serious violent behaviors, as reported in some delusional misidentification disorders related to schizophrenia.The objectives of this work were to clarify the experimental procedures used for familiarity assessment, in order to identify the brain regions that sustain the processing of familiarity. Then, we focused on patients with schizophrenia. Our purpose was to assess the feeling of familiarity in schizophrenia patients, and the consequences of familiarity disorders in these patients on the risk of violence.Several studies have been conducted to meet these objectives. First, we performed separate brain meta-analyses of published neuroimaging data, following the approach employed, in order to determine the brain networks that are involved in the processing of familiarity. Second, we developed an original paradigm for studying the feeling of familiarity that was particularly suited to patients with cognitive disorders, such as patients with schizophrenia. Then, we assessed the association between familiarity disorders and risk of violence by realizing a literature review of published cases of patients having committed violent acts associated to familiarity disorders. Finally, we tried to confirm this association with a systematic evaluation of familiarity disorders of patients with schizophrenia. This last study was conducted in a specific population that was at high-risk of presenting violent behavior, i.e. inmates hospitalized in a psychiatric unit of prison setting.The research presented in this thesis has enabled us to explore familiarity from healthy individuals to psychiatric patients and from the study of neural bases to that of behavioral consequences. The results from these studies confirm the importance to further study familiarity and familiarity disorders, in particular in patients with psychiatric disorders

Etude du sentiment de familiarité chez les patients atteints de schizophrénie, impact sur le risque de comportements violents

Familiarity is the feeling that provides the experience that a person, an object, a place, has been previously encountered independent of any recollection of the associated details. Thus, the feeling of familiarity may be reached even when the stimulus is not clearly recognized. Familiarity has been studied using various approaches. Major research has been conducted in the context of recognition memory and faces recognition.Familiarity disorders have been described as a failure of affective judgment capable of strongly impacting social interactions. They are notably present in some neurological disorders (such as in Alzheimer’s disease) and psychiatric disorders (such as in schizophrenia). Depending on the symptoms severity, these disorders may lead to serious violent behaviors, as reported in some delusional misidentification disorders related to schizophrenia.The objectives of this work were to clarify the experimental procedures used for familiarity assessment, in order to identify the brain regions that sustain the processing of familiarity. Then, we focused on patients with schizophrenia. Our purpose was to assess the feeling of familiarity in schizophrenia patients, and the consequences of familiarity disorders in these patients on the risk of violence.Several studies have been conducted to meet these objectives. First, we performed separate brain meta-analyses of published neuroimaging data, following the approach employed, in order to determine the brain networks that are involved in the processing of familiarity. Second, we developed an original paradigm for studying the feeling of familiarity that was particularly suited to patients with cognitive disorders, such as patients with schizophrenia. Then, we assessed the association between familiarity disorders and risk of violence by realizing a literature review of published cases of patients having committed violent acts associated to familiarity disorders. Finally, we tried to confirm this association with a systematic evaluation of familiarity disorders of patients with schizophrenia. This last study was conducted in a specific population that was at high-risk of presenting violent behavior, i.e. inmates hospitalized in a psychiatric unit of prison setting.The research presented in this thesis has enabled us to explore familiarity from healthy individuals to psychiatric patients and from the study of neural bases to that of behavioral consequences. The results from these studies confirm the importance to further study familiarity and familiarity disorders, in particular in patients with psychiatric disorders.La familiarité correspond au sentiment d’avoir déjà rencontré une personne, un lieu, un objet, indépendamment de la capacité à restituer le contexte initiale de cette rencontre. Le sentiment de familiarité peut ainsi être perçu même si le stimulus dont il s’agit n’est pas clairement identifié. Les travaux menés sur la familiarité s’intègrent dans des domaines de recherche assez variables, les principales recherches ayant été réalisées dans le cadre plus général de l’étude de la mémoire de reconnaissance, et dans le cadre de l’étude de la reconnaissance des visages.Des troubles du sentiment de familiarité peuvent avoir des conséquences importantes sur les interactions sociales. De tels troubles ont notamment été rapportés chez des patients présentant des troubles neurologiques (comme la maladie d’Alzheimer) ou psychiatriques (comme la schizophrénie). En fonction de leur sévérité, ces troubles peuvent être à l’origine de troubles graves du comportement, jusqu’à la réalisation de gestes de violence sévères, comme décrits par exemple dans certains troubles délirants de familiarité associés à la schizophrénie.Les objectifs de ce travail de thèse sont donc de clarifier les méthodes d’évaluation de la familiarité afin d’en préciser les corrélats neuronaux, puis chez les patients souffrant de schizophrénie, d’étudier le sentiment de familiarité, et d’évaluer les conséquences des altérations de ce sentiment, principalement en termes de risque de violence.Plusieurs études ont été menées afin de répondre à ces objectifs. Nous avons tout d’abord réalisé différentes méta-analyses des données d’imagerie de la littérature, selon les méthodes d’évaluation employées, pour déterminer avec précision les réseaux cérébraux impliqués dans le traitement de stimuli familiers. Nous avons ensuite développé une méthode d’étude du sentiment de familiarité permettant de quantifier le sentiment de familiarité, et adaptée aux patients présentant des troubles cognitifs, comme les patients souffrants de schizophrénie. L’évaluation de l’association entre les troubles de la familiarité et le risque de violence a été réalisée à partir d’une revue de littérature des descriptions de cas de gestes violents réalisés dans des contextes de troubles de familiarité pour mettre en évidence les facteurs de risque de violence communs à ces situations cliniques. Afin d’objectiver ces données, nous avons également effectué une évaluation clinique systématique des troubles du sentiment de familiarité des patients souffrant de schizophrénie. Cette étude a été réalisée en population carcérale pour permettre une évaluation au sein d’une population particulièrement à risque de violence.A travers les travaux présentés dans cette thèse, nous avons abordé l’étude de la familiarité, du sujet sain au patient de psychiatrie, de l’étude des mécanismes cérébraux à celle des conséquences comportementales. Les résultats de ces travaux confirment l’importance à accorder à l’étude du sentiment de familiarité, et à celle de ses troubles, en particulier dans les populations de patients psychiatriques

Drug management of agitation in emergency departments: theoretical recommendations and studies of practices

Management of agitation is a frequent problematic of emergency departments that often leads to feelings of insecurity among clinicians. There are various practices regarding the drugs to be used in the management of agitations. Guidelines have been proposed by different groups of experts concerning the antipsychotic drugs that should be used for agitations in psychiatric conditions. Nevertheless, there is no clear-cut procedure referring to the utilization of intramuscular drugs in this situation. Moreover, there is no comparison available between the commonly used medications and other drugs, both in terms of superiority of efficacy and tolerance. In order to accurately assess these practices, evaluation protocols must minimize the interference with the service organization and the routine care. Further studies are required in order to develop guidelines about medications that have to be used to handle agitations, which must be based on robust evidence and applicable to emergency services

Somatic symptom disorders and long COVID: A critical but overlooked topic

International audienc