Deafferentation as a cause of hallucinations

Purpose of review The association between hallucinations and sensory loss, especially vision- and hearing-impairment, has been firmly established over the past years. The deafferentation theory, a decrease of the threshold for activation in the brain and the consequential imbalance between excitatory and inhibitory brain networks, is hypothesized to underly this relationship. Here we review the studies investigating this theory with a focus on the most recent literature to better understand the contribution of sensory loss to hallucinations. Recent findings A large cross-sectional study has recently confirmed the relationship between auditory impairment and deafferentation. However, the underlying mechanisms of deafferentation are still under debate, with hyperexcitability and deviations in bottom-up and top-down processes being the most likely explanations. Social isolation following sensory impairment increases the risk for hallucinations. Better knowledge and awareness about the contribution of deafferentation and loneliness would benefit diagnosis and treatment of hallucinations. Summary Studies imply activity in higher order areas, corresponding to the functional mapping of sensory system, and a general state of higher excitability as neurobiological explanation. Auditory deafferentation, tinnitus and other auditory hallucinations, likely lie on a continuum. Social isolation mediates psychotic symptoms in sensory-impaired individuals. Currently, there is no stand...
Source: Current Opinion in Psychiatry - Category: Psychiatry Tags: SCHIZOPHRENIA AND RELATED DISORDERS: Edited by Lynn E. DeLisi and Iris E.C. Sommer Source Type: research

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Source: SafetyLit - Category: International Medicine & Public Health Tags: Risk Factor Prevalence, Injury Occurrence Source Type: news
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Source: SafetyLit - Category: International Medicine & Public Health Tags: Age: Adolescents Source Type: news
Conditions:   Schizophrenia;   Parkinson Disease;   Hallucinations Intervention:   Sponsors:   University of Cambridge;   Cambridge University Hospitals NHS Foundation Trust;   Cambridgeshire and Peterborough NHS Foundation Trust Not yet recruiting
Source: ClinicalTrials.gov - Category: Research Source Type: clinical trials
CONCLUSIONS: Trials of antidepressants may be driven mainly by commercial interests, focusing on prevalent diseases and everyday problems. No one can live a full life without experiencing several of the problems for which these drugs were tested. Antidepressants, sometimes called happy pills, could be seen as the modern version of Aldous Huxley's soma pill intended to keep everyone happy in the "Brave New World". PMID: 32444565 [PubMed - as supplied by publisher]
Source: International Journal of Risk and Safety in Medicine - Category: Drugs & Pharmacology Tags: Int J Risk Saf Med Source Type: research
Publication date: September 2020Source: Schizophrenia Research: Cognition, Volume 21Author(s): Sivan Regev, Naomi Josman
Source: Schizophrenia Research: Cognition - Category: Psychiatry Source Type: research
Authors: Yang H, Wang M, Wu F, Li Q, Zheng Y, Qin P Abstract Auditory hallucinations in schizophrenia (SCZ-AH) and subjective tinnitus (TN) are two conditions that share a superficial resemblance, namely the presence of phantom sounds produced by the brain. A crucial difference between them lies in the self-processing of the phantom signals, which is intact in TN patients but lost in SCZ-AH. Our study sets out to investigate the potential neural mechanisms for this crucial psychotic symptom of SCZ-AH under the framework of self. We gathered resting-state fMRI data from three participant groups: SCZ-AH, TN and healt...
Source: Asian Journal of Psychiatry - Category: Psychiatry Tags: Asian J Psychiatr Source Type: research
Conclusion The first crystal structure of a human nAChR domain with an α-Ctx is presented. The structure revealed the interactions between α-Ctx RgIA and the (+) side of neuronal nAChR α9-ECD in high detail. Based on the structure of this complex, models of human α9α10 nAChR ECD with fully formed binding sites were constructed with RgIA bound to each of them. Our MD simulations suggest that the favorable binding site of RgIA in the human α9α10 nAChR ECD consists of either α9 or α10 subunits as the (+) side and of an adjacent α9 rather than α10 subunit as th...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
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Source: Journal of Affective Disorders - Category: Neurology Authors: Tags: Research paper Source Type: research
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Source: JAMA Neurology - Category: Neurology Source Type: research
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Source: Schizophrenia Bulletin - Category: Psychiatry Source Type: research
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