RESUMO
Visual hallucinations are common in older people and are especially associated with ophthalmological and neurological disorders, including dementia and Parkinson's disease. Uncertainties remain whether there is a single underlying mechanism for visual hallucinations or they have different disease-dependent causes. However, irrespective of mechanism, visual hallucinations are difficult to treat. The National Institute for Health Research (NIHR) funded a research programme to investigate visual hallucinations in the key and high burden areas of eye disease, dementia and Parkinson's disease, culminating in a workshop to develop a unified framework for their clinical management. Here we summarise the evidence base, current practice and consensus guidelines that emerged from the workshop.Irrespective of clinical condition, case ascertainment strategies are required to overcome reporting stigma. Once hallucinations are identified, physical, cognitive and ophthalmological health should be reviewed, with education and self-help techniques provided. Not all hallucinations require intervention but for those that are clinically significant, current evidence supports pharmacological modification of cholinergic, GABAergic, serotonergic or dopaminergic systems, or reduction of cortical excitability. A broad treatment perspective is needed, including carer support. Despite their frequency and clinical significance, there is a paucity of randomised, placebo-controlled clinical trial evidence where the primary outcome is an improvement in visual hallucinations. Key areas for future research include the development of valid and reliable assessment tools for use in mechanistic studies and clinical trials, transdiagnostic studies of shared and distinct mechanisms and when and how to treat visual hallucinations.
Assuntos
Oftalmopatias/complicações , Alucinações/etiologia , Doenças do Sistema Nervoso/complicações , Demência/complicações , Demência/fisiopatologia , Demência/terapia , Oftalmopatias/fisiopatologia , Oftalmopatias/terapia , Alucinações/fisiopatologia , Alucinações/terapia , Humanos , Doenças do Sistema Nervoso/fisiopatologia , Doenças do Sistema Nervoso/terapia , Doença de Parkinson/complicações , Doença de Parkinson/fisiopatologia , Doença de Parkinson/terapiaRESUMO
Introduction: It has been proposed that hallucinations occur because of problems with reality discrimination (when internal, self-generated cognitions are misattributed to an external, non-self source) and because of elevated levels of top-down processing. In this study, we examined whether visual reality discrimination abilities and elevated top-down processing (assessed via face pareidolia-proneness) were associated with how often non-clinical participants report visual hallucination-like experiences.Methods: Participants (N = 82, mean age = 23.12 years) completed a visual reality discrimination task and a face pareidolia task, as well as self-report measures of schizotypy and of the frequency of visual hallucination-like experiences.Results: Regression analysis demonstrated that the number of false alarms made on the visual reality discrimination task and the number of hits made on the face pareidolia task were independent predictors of the frequency of visual hallucination-like experiences. Correlations between performance on the tasks and levels of schizotypy were not statistically significant.Conclusions: These findings suggest that weaker visual reality discrimination abilities and elevated levels of top-down processing are associated with visual hallucination-proneness and are discussed in terms of the idea that clinical visual hallucinations and non-clinical visual hallucination-like experiences share similar cognitive mechanisms.
Assuntos
Discriminação Psicológica/fisiologia , Alucinações/diagnóstico , Alucinações/psicologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Cognição/fisiologia , Feminino , Humanos , Masculino , Autorrelato , Adulto JovemRESUMO
BACKGROUND: Antipsychotic drugs are usually the first line of treatment for schizophrenia; however, many patients refuse or discontinue their pharmacological treatment. We aimed to establish whether cognitive therapy was effective in reducing psychiatric symptoms in people with schizophrenia spectrum disorders who had chosen not to take antipsychotic drugs. METHODS: We did a single-blind randomised controlled trial at two UK centres between Feb 15, 2010, and May 30, 2013. Participants aged 16-65 years with schizophrenia spectrum disorders, who had chosen not to take antipsychotic drugs for psychosis, were randomly assigned (1:1), by a computerised system with permuted block sizes of four or six, to receive cognitive therapy plus treatment as usual, or treatment as usual alone. Randomisation was stratified by study site. Outcome assessors were masked to group allocation. Our primary outcome was total score on the positive and negative syndrome scale (PANSS), which we assessed at baseline, and at months 3, 6, 9, 12, 15, and 18. Analysis was by intention to treat, with an ANCOVA model adjusted for site, age, sex, and baseline symptoms. This study is registered as an International Standard Randomised Controlled Trial, number 29607432. FINDINGS: 74 individuals were randomly assigned to receive either cognitive therapy plus treatment as usual (n=37), or treatment as usual alone (n=37). Mean PANSS total scores were consistently lower in the cognitive therapy group than in the treatment as usual group, with an estimated between-group effect size of -6.52 (95% CI -10.79 to -2.25; p=0.003). We recorded eight serious adverse events: two in patients in the cognitive therapy group (one attempted overdose and one patient presenting risk to others, both after therapy), and six in those in the treatment as usual group (two deaths, both of which were deemed unrelated to trial participation or mental health; three compulsory admissions to hospital for treatment under the mental health act; and one attempted overdose). INTERPRETATION: Cognitive therapy significantly reduced psychiatric symptoms and seems to be a safe and acceptable alternative for people with schizophrenia spectrum disorders who have chosen not to take antipsychotic drugs. Evidence-based treatments should be available to these individuals. A larger, definitive trial is needed. FUNDING: National Institute for Health Research.
Assuntos
Antipsicóticos , Terapia Cognitivo-Comportamental , Esquizofrenia/terapia , Recusa do Paciente ao Tratamento/psicologia , Inglaterra , Estudos de Viabilidade , Feminino , Humanos , Masculino , Método Simples-Cego , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Despite decades of research, we do not definitively know how people sometimes see things that are not there. Eight models of complex visual hallucinations have been published since 2000, including Deafferentation, Reality Monitoring, Perception and Attention Deficit, Activation, Input, and Modulation, Hodological, Attentional Networks, Active Inference, and Thalamocortical Dysrhythmia Default Mode Network Decoupling. Each was derived from different understandings of brain organisation. To reduce this variability, representatives from each research group agreed an integrated Visual Hallucination Framework that is consistent with current theories of veridical and hallucinatory vision. The Framework delineates cognitive systems relevant to hallucinations. It allows a systematic, consistent, investigation of relationships between the phenomenology of visual hallucinations and changes in underpinning cognitive structures. The episodic nature of hallucinations highlights separate factors associated with the onset, persistence, and end of specific hallucinations suggesting a complex relationship between state and trait markers of hallucination risk. In addition to a harmonised interpretation of existing evidence, the Framework highlights new avenues of research, and potentially, new approaches to treating distressing hallucinations.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Alucinações , Humanos , Alucinações/psicologia , EncéfaloRESUMO
Hallucinations can occur in different sensory modalities, both simultaneously and serially in time. They have typically been studied in clinical populations as phenomena occurring in a single sensory modality. Hallucinatory experiences occurring in multiple sensory systems-multimodal hallucinations (MMHs)-are more prevalent than previously thought and may have greater adverse impact than unimodal ones, but they remain relatively underresearched. Here, we review and discuss: (1) the definition and categorization of both serial and simultaneous MMHs, (2) available assessment tools and how they can be improved, and (3) the explanatory power that current hallucination theories have for MMHs. Overall, we suggest that current models need to be updated or developed to account for MMHs and to inform research into the underlying processes of such hallucinatory phenomena. We make recommendations for future research and for clinical practice, including the need for service user involvement and for better assessment tools that can reliably measure MMHs and distinguish them from other related phenomena.