Time discrimination in psychosis: findings from a neuroimaging study

Introduction Previous functional neuroimaging studies have demonstrated a brain network responsible of time discrimination (TD) processes, which may play a significant mediating role in other cognitive processes, such as change detection and cognitive control. The study of TD and its dysfunction in psychosis has become a matter of growing interest. We hypothesize that the impairment of the TD network is involved both in the mechanisms of psychosis and in the cognitive deficit presented by patients. Objectives To delimit the brain regions involved in TD. To examine the dysfunction in TD brain network in patients diagnosed with psychosis. To sudy the integrity of brain white matter pathways in psychosis. To verify whether the neuroimaging findings and TD test performance predict the neurocognitive profile of the patients. Methods Participants included 20 patients with psychosis (PSY group) and 13 healthy controls (HC group). PSY group participants met remission criteria for 6 months prior to the study. Participants were interviewed for sociodemographic information and clinical assessments. They underwent a detailed cognitive assesment using the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB). Neuroimaging study was performed on a 3 Tesla MRI scanner. We designed an experimental task including a test tool to assess TD and Oddbal detection (OD) paradigms with a cognitive control component. The task was conducted under functional magentic resonance imaging (fMRI). We used the general linear model analysis of the individual data of the fMRI images and the random effects model for group inference. Group differences in DTI were tested using tract-based spatial statistics (TBSS). Results We find statistically significant differences (fMRI) in the activity related to TD (in HC), with greater activity in frontal cortical regions, the insular cortex and the cerebellum. In the PSY group, differences in the functionality and activation pattern of brain networks responsible for TD are observed, although voxel clustering does not reach the cluster significance limit when compared to HC. Compared to the HC, the PSY group has a significant deficit of fractional anisotropy (DTI) in the whole brain and in 21 specific brain regions. The PSY group has significantly lower scores in six of the seven cognitive domains than the control group, as well as in the overall composite. We correlated FA values in the groups of interest with MCCB scores. Image: Image 2: Image 3: Conclusions We have defined the TD network, its relationship with other brain networks and cognitive processes of more complexity. The inclusion of participants with stable psychosis allowed us to analyze de TD disfunction in the PSY group. We compared the integrity of TD related brain pathways and correlated the findings with various clinical characteristics and the cognitive impairment present in psychotic patients. Disclosure of Interest None Declared


Introduction:
Previous functional neuroimaging studies have demonstrated a brain network responsible of time discrimination (TD) processes, which may play a significant mediating role in other cognitive processes, such as change detection and cognitive control.The study of TD and its dysfunction in psychosis has become a matter of growing interest.We hypothesize that the impairment of the TD network is involved both in the mechanisms of psychosis and in the cognitive deficit presented by patients.Objectives: 1.To delimit the brain regions involved in TD. 2. To examine the dysfunction in TD brain network in patients diagnosed with psychosis.3. To sudy the integrity of brain white matter pathways in psychosis.4. To verify whether the neuroimaging findings and TD test performance predict the neurocognitive profile of the patients.
Methods: Participants included 20 patients with psychosis (PSY group) and 13 healthy controls (HC group).PSY group participants met remission criteria for 6 months prior to the study.Participants were interviewed for sociodemographic information and clinical assessments.They underwent a detailed cognitive assesment using the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB).
Neuroimaging study was performed on a 3 Tesla MRI scanner.We designed an experimental task including a test tool to assess TD and Oddbal detection (OD) paradigms with a cognitive control component.The task was conducted under functional magentic resonance imaging (fMRI).We used the general linear model analysis of the individual data of the fMRI images and the random effects model for group inference.Group differences in DTI were tested using tract-based spatial statistics (TBSS).
Results: We find statistically significant differences (fMRI) in the activity related to TD (in HC), with greater activity in frontal cortical regions, the insular cortex and the cerebellum.In the PSY group, differences in the functionality and activation pattern of brain networks responsible for TD are observed, although voxel clustering does not reach the cluster significance limit when compared to HC.Compared to the HC, the PSY group has a significant deficit of fractional anisotropy (DTI) in the whole brain and in 21 specific brain regions.The PSY group has significantly lower scores in six of the seven cognitive domains than the control group, as well as in the overall composite.We correlated FA values in the groups of interest with MCCB scores.
We have defined the TD network, its relationship with other brain networks and cognitive processes of more complexity.The inclusion of participants with stable psychosis allowed us to analyze de TD disfunction in the PSY group.We compared the integrity of TD related brain pathways and correlated the findings with various clinical characteristics and the cognitive impairment present in psychotic patients.Disclosure of Interest: None DeclaredSchizophrenia and Psychosis 2 O0135 Profile of patients undergoing treatment with longacting injectable antipsychotic drugs in a psychiatry hospital in Portugal Introduction: The treatment with long-acting injectable antipsychotics (LAIAs) is more and more frequent and it shows advantages regarding adherence, effectiveness and tolerance.Objectives: To describe and compare the profile of patients under treatment with LAIAs in a psychiatric hospital in Portugal.Methods: An observational and retrospective study was carried out with the collection of data referring to patients hospitalized with a first psychotic episode between 01/01/2019 and 30/06/2022 in a psychiatric hospital in Portugal and the respective evaluation of sociodemographic and clinical data through the information recorded in the clinical files.Results: During the 42 months of the study, we selected 78 patients who presented psychotic symptoms on admission.Patients with a history of previous psychotic episodes and prescription of antipsychotic therapy prior to hospitalization were excluded.Of 78 patients hospitalized with a first psychotic episode, 34 -which corresponds to approximately 44% -were discharged with LAIAs.Patients receiving LAIAs had an average age of 39 years.The average number of days of hospitalization was 28 days; 41% were female (n=14) and 59 were male (n=20); 35% (n=12) consumed psychoactive substances previously on admission to hospital; 62% (n=21) were discharged under the compulsive treatment regimen.Regarding the diagnosis at discharge, based on the international classification of disease-11 (ICD-11), the most common were schizophrenia, psychotic disorder induced by psychoactive substances and acute and transient psychotic disorder.From the statistical analysis carried out, no correlation was observed between the rate of readmissions and the administration of LAIAs, nor was there any correlation between the rate of readmissions and compulsive outpatient treatment.Conclusions: Despite what is described in the literature, in the sample under study, the LAIAs were not superior in the variables studied, namely in reducing the readmission rate.Possible explanations for the results obtained may be justified by the size of the sample under study and the follow-up time of the cases.Disclosure of Interest: None Declared