Learned irrelevance (LIrr) is a pre-exposure effect in which uncorrelated presentations of a conditioned stimulus (CS) and an unconditioned stimulus (US) retard subsequent CS-US association. LIrr is closely related to the phenomenon of latent inhibition (LI). LI refers to the retarding effects of inconsequential stimulus pre-exposure on subsequent conditioning to that stimulus, and is considered to reflect the organism's capacity to ignore irrelevant stimuli. LI is disrupted in schizophrenia patients, due to faster learning of the association between the preexposed CS and the US. A new within-subject target-recognition LIrr procedure was applied. The target was either cued by a priming signal or appeared at random, and priming signals were novel or preexposed cues. Schizophrenia patients were compared to age- and sex-matched control subjects. Normal subjects (n = 24) have shown robust LIrr, namely, faster cue-target associations of novel compared to preexposed cues. Schizophrenia patients at the early stages of their first episode (n = 7) showed LIrr disruption, namely, cue-target associations to preexposed cues were as fast as for novel cues. Chronic patients during an acute phase (n = 18) did not show LIrr as they failed to learn the cue-target association. In addition to the LIrr paradigm the same subjects were tested in a covert-orientation task. No differences were observed between the groups on this task. The possible advantages of the new LIrr paradigm are discussed.
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http://dx.doi.org/10.1016/j.bbr.2004.11.017 | DOI Listing |
Tzu Chi Med J
August 2024
Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.
Schizophrenia (SCZ) is a chronic psychotic disorder that profoundly alters an individual's perception of reality, resulting in abnormal behavior, cognitive deficits, thought distortions, and disorientation in emotions. Many complicated factors can lead to SCZ, and investigations are ongoing to understand the neurobiological underpinnings of this condition. Presynaptic Netrin G1 and its cognate partner postsynaptic Netrin-G-Ligand-1 (NGL-1) have been implicated in SCZ.
View Article and Find Full Text PDFInt J Psychiatry Med
January 2025
Department of Public Health, Official University of Ruwenzori, Goma, North-Kivu Democratic Republic of the Congo.
Objective: Although religious leaders play an important role in providing informal mental health care to individuals struggling to seek religious and spiritual care, existing studies have not explored the magnitude of psychiatric symptoms and motivators to seek mental health services from religious leaders in religious listening centers and mental hospitals. This paper presents preliminary data from a survey aimed at assessing psychiatric symptoms and factors associated with access to spiritual services among 151 individuals at a religious listening center, as well as to determine the pathways of care among 150 patients attending a mental health clinic in conflict zones of the Eastern Democratic Republic of the Congo.
Method: Three hundred and one participants were screened for psychiatric symptoms and factors motivating access to religious leaders using a semi-structured questionnaire.
BMC Psychiatry
January 2025
Facultad de Medicina, Universidad Peruana Cayetano Heredia, Lima, Peru.
Background: Schizophrenia is a complex psychiatric disorder, and in patients treated with clozapine, it may induce or exacerbate obsessive-compulsive symptoms (OCS), which negatively affect patients' quality of life, functionality and treatment adherence. Despite its clinical relevance, the reported prevalence and characteristics of clozapine associated OCS vary widely, limiting effective management.
Objective: This scoping review synthesizes evidence on the prevalence of OCS in patients with schizophrenia treated with clozapine and explores treatment characteristics (types, severity, dose, and time to onset/exacerbation).
Lancet Psychiatry
February 2025
Department of Forensic Psychiatry, University of Eastern Finland, Niuvanniemi Hospital, Kuopio, Finland; Department of Clinical Neuroscience, Karolinska Institutet, Solna, Sweden; Center for Psychiatry Research, Stockholm City Council, Stockholm, Sweden; Neuroscience Center, University of Helsinki, Helsinki, Finland.
Background: The best pharmacological treatment practices for relapse prevention in patients with first-episode schizophrenia are unclear. We aimed to assess different treatment strategies used before and after the first relapse, and their associations with subsequent relapse risk.
Methods: In this population-based cohort study, we enrolled individuals (aged ≤45 years) with first-episode schizophrenia who were hospitalised and subsequently relapsed between 1996 and 2014 from the nationwide Finnish Hospital Discharge Register.
Chest
January 2025
Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; Division of Critical Care, Department of Medicine, University of Ottawa, Ottawa, ON, Canada; Institut du Savoir Montfort, Hôpital Montfort, Ottawa, ON, Canada.
Background: Survivorship after coronavirus disease 2019 (COVID-19) critical illness may be associated with important long-term sequelae, but little is known regarding mental health outcomes.
Research Question: What is the association between COVID-19 critical illness and new post-discharge mental health diagnoses.
Study Design: AND METHODS: We conducted a population-based cohort study in Ontario, Canada (January 1, 2020-March 31, 2022).
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