Plasma complement and coagulation proteins as prognostic factors of negative symptoms: An analysis of the NAPLS 2 and 3 studies.

INTRODUCTION: Negative symptoms impact the quality of life of individuals with psychosis and current treatment options for negative symptoms have limited effectiveness. Previous studies have demonstrated that complement and coagulation pathway protein levels are related to later psychotic experiences, psychotic disorder, and functioning. However, the prognostic relationship between complement and coagulation proteins and negative symptoms is poorly characterised. METHODS: In the North American Prodrome Longitudinal Studies 2 and 3, negative symptoms in 431 individuals at clinical high-risk for psychosis (mean age: 18.2, SD 3.6; 42.5 % female) were measured at multiple visits over 2 years using the Scale of Psychosis-Risk Symptoms. Plasma proteins were quantified at baseline using mass spectrometry. Four factors were derived to represent levels of proteins involved in the activation or regulation of the complement or coagulation systems. The relationships between standardised protein group factors and serial measurements of negative symptoms over time were modelled using generalised least squares regression. Analyses were adjusted for baseline candidate prognostic factors: negative symptoms, positive symptoms, functioning, depressive symptoms, suicidal ideation, cannabis use, tobacco use, antipsychotic use, antidepressant use, age, and sex. RESULTS: Clinical and demographic prognostic factors of follow-up negative symptoms included negative, positive, and depressive symptoms, functioning, and age. Adjusting for all candidate prognostic factors, the complement regulators group and the coagulation regulators group were identified as prognostic factors of follow-up negative symptoms (ß: 0.501, 95 % CI: 0.160, 0.842; ß: 0.430, 95 % CI: 0.080, 0.780 respectively. The relationship between complement regulator levels and negative symptoms was also observed in NAPLS2 alone (ß: 0.501, 95 % CI: -0.037, 1.039) and NAPLS3 alone, additionally adjusting for BMI (ß: 0.442, 95 % CI: 0.127, 0.757). CONCLUSION: The results indicate that plasma complement and coagulation regulator levels are prognostic factors of negative symptoms, independent of clinical and demographic prognostic factors. These results suggest complement and coagulation regulator levels could have potential utility in informing treatment decisions for negative symptoms in individuals at risk.

Adjunctive canakinumab reduces peripheral inflammation markers and improves positive symptoms in people with schizophrenia and inflammation: A randomized control trial.

BACKGROUND: Clinical trials of anti-inflammatories in schizophrenia do not show clear and replicable benefits, possibly because patients were not recruited based on elevated inflammation status. Interleukin 1-beta (IL-1ß) mRNA and protein levels are increased in serum, plasma, cerebrospinal fluid, and brain of some chronically ill patients with schizophrenia, first episode psychosis, and clinical high-risk individuals. Canakinumab, an approved anti-IL-1ß monoclonal antibody, interferes with the bioactivity of IL-1ß and interrupts downstream signaling. However, the extent to which canakinumab reduces peripheral inflammation markers, such as, high sensitivity C-reactive protein (hsCRP) and symptom severity in schizophrenia patients with inflammation is unknown. TRIAL DESIGN: We conducted a randomized, placebo-controlled, double-blind, parallel groups, 8-week trial of canakinumab in chronically ill patients with schizophrenia who had elevated peripheral inflammation. METHODS: Twenty-seven patients with schizophrenia or schizoaffective disorder and elevated peripheral inflammation markers (IL-1ß, IL-6, hsCRP and/or neutrophil to lymphocyte ratio: NLR) were randomized to a one-time, subcutaneous injection of canakinumab (150 mg) or placebo (normal saline) as an adjunctive antipsychotic treatment. Peripheral blood hsCRP, NLR, IL-1ß, IL-6, IL-8 levels were measured at baseline (pre injection) and at 1-, 4- and 8-weeks post injection. Symptom severity was assessed at baseline and 4- and 8-weeks post injection. RESULTS: Canakinumab significantly reduced peripheral hsCRP over time, F(3, 75) = 5.16, p = 0.003. Significant hsCRP reductions relative to baseline were detected only in the canakinumab group at weeks 1, 4 and 8 (p's = 0.0003, 0.000002, and 0.004, respectively). There were no significant hsCRP changes in the placebo group. Positive symptom severity scores were significantly reduced at week 8 (p = 0.02) in the canakinumab group and week 4 (p = 0.02) in the placebo group. The change in CRP between week 8 and baseline (b = 1.9, p = 0.0002) and between week 4 and baseline (b = 6.0, p = 0.001) were highly significant predictors of week 8 change in PANSS Positive Symptom severity scores. There were no significant changes in negative symptoms, general psychopathology or cognition in either group. Canakinumab was well tolerated and only 7 % discontinued. CONCLUSIONS: Canakinumab quickly reduces peripheral hsCRP serum levels in patients with schizophrenia and inflammation; after 8 weeks of canakinumab treatment, the reductions in hsCRP are related to reduced positive symptom severity. Future studies should consider increased doses or longer-term treatment to confirm the potential benefits of adjunctive canakinumab in schizophrenia. Australian and New Zealand Clinical Trials Registry number: ACTRN12615000635561.

Association between social support and the severity of positive symptoms in rural community-dwelling patients with schizophrenia during the COVID-19 pandemic.

BACKGROUND: This study examined the association between social support and the severity of positive symptoms in rural community-dwelling schizophrenia patients during the COVID-19 pandemic. METHOD: The cross-sectional study included 665 rural community-dwelling schizophrenia patients investigated during the COVID-19 pandemic. Social support was measured using the Social Support Rating Scale, and positive symptoms were assessed using the Positive Scale extracted from the Positive and Negative Syndrome Scale. Multiple linear regression was adopted to examine the association of social support with positive symptoms. RESULT: The scores for total social support, subjective support, objective support and the use of social support were 28.3 ± 5.9, 16.4 ± 5.2, 6.5 ± 1.4 and 5.4 ± 2.8, respectively. Total social support (ß = -0.08, 95%CI: -0.13 to -0.02, P < 0.01) and subjective social support (ß = -0.10, 95%CI: -0.16 to -0.04, P < 0.01) were significantly and negatively associated with the Positive Scale score after adjustment for confounders. Objective social support (ß = 0.11, 95%CI: -0.10 to 0.32, P = 0.31) and the use of social support (ß = -0.03, 95%CI: -0.14 to 0.07, P = 0.53) were not significantly associated with the Positive Scale score. CONCLUSION: The study confirmed the importance of social support, especially subjective support, provided to rural community-dwelling schizophrenia patients during the COVID-19 pandemic. This support should be addressed and strengthened for such patients in emergent events.

The positive dimension of schizotypy is associated with self-report measures of autobiographical memory and future thinking but not experimenter-scored indices.

ABSTRACTThe ability to remember our past and to imagine the future are critical to our sense of self. Previous research has indicated that they are disrupted in schizophrenia. However, it is unclear (i) whether this is found when examining experimenter-scored indices of content and/or participants' self-report of phenomenological characteristics, and (ii) how these abilities might be related to symptoms. This study sought to address these questions by taking a dimensional approach and measuring positive and negative schizotypal experiences in healthy people (n = 90). Participants were given cue words. For some, they remembered an event from the past and for others they generated an event in the future. No significant relationships were found with any aspect of schizotypy when participants' descriptions were scored by the experimenter according to a standardised episodic content measure. In contrast, several significant positive correlations were observed for past memory and future thinking when examining the positive dimension of schizotypy and participants' ratings, particularly to sensory characteristics of the experience and mental pre- or reliving. These results indicate enhanced subjective experiences of autobiographical memory and future thinking in those who report delusional and hallucinatory-like occurrences, which might be linked to mental imagery or metacognitive alterations.

Clinical utility of the at-risk for psychosis state beyond transition: A multidimensional network analysis.

To be relevant to healthcare systems, the clinical high risk for psychosis (CHR-P) concept should denote a specific (i.e., unique) clinical population and provide useful information to guide the choice of intervention. The current study applied network analyses to examine the clinical specificities of CHR-P youths compared to general help-seekers and non-CHR-P youth. 146 CHR-P (mean age = 14.32 years) and 103 non-CHR-P (mean age = 12.58 years) help-seeking youth were recruited from a neuropsychiatric unit and assessed using the Structured Interview for Psychosis-Risk Syndromes, Children's Depression Inventory, Multidimensional Anxiety Scale for Children, Global Functioning: Social, Global Functioning: Role, and Wechsler Intelligence Scale for Children/Wechsler Adult Intelligence Scale. The first network structure comprised the entire help-seeking sample (i.e., help-seekers network), the second only CHR-P patients (i.e., CHR-P network), and the third only non-CHR-P patients (i.e., non-CHR-P network). In the help-seekers network, each variable presented at least one edge. In the CHR-P network, two isolated "archipelagos of symptoms" were identified: (a) a subgraph including functioning, anxiety, depressive, negative, disorganization, and general symptoms; and (b) a subgraph including positive symptoms and the intelligence quotient. In the non-CHR-P network, positive symptoms were negatively connected to functioning, disorganization, and negative symptoms. Positive symptoms were less connected in the CHR-P network, indicating a need for specific interventions alongside those treating comorbid disorders. The findings suggest specific clinical characteristics of CHR-P youth to guide the development of tailored interventions, thereby supporting the clinical utility of the CHR-P concept.

Ketamine disrupts locomotion and electrolocation in a novel model of schizophrenia, Gnathonemus petersii fish.

The present study aimed to examine a weakly electric fish Gnathonemus petersii (G. petersii) as a candidate model organism of glutamatergic theory of schizophrenia. The idea of G. petersii elevating the modeling of schizophrenia symptoms is based on the fish's electrolocation and electrocommunication abilities. Fish were exposed to the NMDA antagonist ketamine in two distinct series differing in the dose of ketamine. The main finding revealed ketamine-induced disruption of the relationship between electric signaling and behavior indicating impairment of fish navigation. Moreover, lower doses of ketamine significantly increased locomotion and erratic movement and higher doses of ketamine reduced the number of electric organ discharges indicating successful induction of positive schizophrenia-like symptoms and disruption of fish navigation. Additionally, a low dose of haloperidol was used to test the normalization of the positive symptoms to suggest a predictive validity of the model. However, although successfully induced, positive symptoms were not normalized using the low dose of haloperidol; hence, more doses of the typical antipsychotic haloperidol and probably also of a representative of atypical antipsychotic drugs need to be examined to confirm the predictive validity of the model.

Differential Impacts of Endogenous Antioxidants on Clinical Symptoms and Cognitive Function in Acute and Chronic Schizophrenia Patients.

BACKGROUND: Impaired antioxidant defense is implicated in the pathophysiology of schizophrenia, and superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) are 3 first-line endogenous antioxidants. Various cognitive functions decline differently during the schizophrenia course. The characteristic roles of the 3 antioxidants in clinical and cognitive profiles in acute and chronic phases of schizophrenia require study. METHODS: We recruited 311 patients with schizophrenia, including 92 acutely exacerbated patients who had been off antipsychotics for at least 2 weeks and 219 chronic patients who had been stable on medication for at least 2 months. Blood SOD, CAT, and GSH levels; clinical symptoms; and 9 cognitive test scores were measured. RESULTS: Blood CAT levels were higher in the acute patients than in the chronic patients, whereas SOD and GSH levels were similar to one another. Higher CAT levels were correlated with less positive symptoms, better working memory and problem solving in the acute phase, and less negative symptoms, less general psychopathology, better global assessment of function, and better cognitive function (in speed of processing, attention, problem solving) in the chronic period. Higher SOD levels were correlated with better global assessment of function in the acute phase and better speed of processing, working memory, and verbal learning and memory in the chronic period. GSH influenced neither clinical nor cognitive manifestations. CONCLUSIONS: This study showed that blood CAT affected different clinical and cognitive domains between acute and chronic stages of schizophrenia, SOD influenced cognitive functions in chronic state, but GSH affected none. Further studies are needed to explore the underlying mechanisms.

Evidence for functional improvement in reward anticipation in recent onset schizophrenia after one year of coordinated specialty care.

BACKGROUND: Motivational impairment associated with deficits in processing the anticipation of future reward is hypothesized to be a cardinal feature of schizophrenia spectrum disorders (SZ). Evidence from short-term follow-up (6-week post-treatment) studies suggests that these deficits may improve or be reversed with treatment, although longer-term outcomes are unknown. Here we examined the one-year trajectory of functional activation in brain circuitry associated with reward anticipation in people with recent onset SZ who participated in coordinated specialty care (CSC) treatment, hypothesizing normalization of brain response mirroring previous short-term findings in first-episode individuals. METHOD: Blood oxygen level-dependent (BOLD) response in the dorsal anterior cingulate cortex, anterior insula, and ventral striatum (VS) associated with reward anticipation during the Incentivized Control Engagement Task (ICE-T) was analyzed in a baseline sample of 49 healthy controls (HCs) and 52 demographically matched people with SZ, with follow-up data available for 35 HCs and 17 people with SZ. RESULTS: In agreement with our hypothesis, significant time × diagnosis interactions were observed across all regions, in which reward anticipation-associated BOLD response increased in SZ to above baseline HC levels at follow-up. Increased VS activation was associated with decreased reality distortion symptoms over the follow-up period. Baseline reward anticipation-associated BOLD response in the right anterior insula was associated with improvement in reality distortion symptoms. CONCLUSIONS: These findings suggest that functional deficits in reward anticipation may be reversed after one year of CSC in recent onset participants with SZ, and that this improvement is associated with reduced positive symptoms in the illness.

Longitudinal symptomatic interactions in long-standing schizophrenia: a novel five-point analysis based on directed acyclic graphs.

BACKGROUND: Recent network models propose that mutual interaction between symptoms has an important bearing on the onset of schizophrenic disorder. In particular, cross-sectional studies suggest that affective symptoms may influence the emergence of psychotic symptoms. However, longitudinal analysis offers a more compelling test for causation: the European Schizophrenia Cohort (EuroSC) provides data suitable for this purpose. We predicted that the persistence of psychotic symptoms would be driven by the continuing presence of affective disturbance. METHODS: EuroSC included 1208 patients randomly sampled from outpatient services in France, Germany and the UK. Initial measures of psychotic and affective symptoms were repeated four times at 6-month intervals, thereby furnishing five time-points. To examine interactions between symptoms both within and between time-slices, we adopted a novel technique for modelling longitudinal data in psychiatry. This was a form of Bayesian network analysis that involved learning dynamic directed acyclic graphs (DAGs). RESULTS: Our DAG analysis suggests that the main drivers of symptoms in this long-term sample were delusions and paranoid thinking. These led to affective disturbance, not vice versa as we initially predicted. The enduring relationship between symptoms was unaffected by whether patients were receiving first- or second-generation antipsychotic medication. CONCLUSIONS: In this cohort of people with chronic schizophrenia treated with medication, symptoms were essentially stable over long periods. However, affective symptoms appeared driven by the persistence of delusions and persecutory thinking, a finding not previously reported. Although our findings as ever remain hostage to unmeasured confounders, these enduring psychotic symptoms might nevertheless be appropriate candidates for directly targeted psychological interventions.

Retinal layers and symptoms and inflammation in schizophrenia.

Schizophrenia is a neurodevelopmental disorder that affects brain structure and function. The retina, as well as the brain, consists of neuronal and glial cells packed in layers. Cortical volume and brain thickness are associated with inflammatory biomarkers, however, no study has been performed associating inflammatory biomarkers and retina in schizophrenia. our study aims to compare the retinal macular thickness and volume and peripapillary thickness in patients with schizophrenia and controls, and associate it to symptoms of schizophrenia, to interleukin-6 (IL-6) and C Reactive Protein (CRP) levels. Optical coherence tomography was performed to assess retinal layer thickness and volume, and CRP and IL-6 levels were measured in patients with schizophrenia and controls. Positive, negative, and general symptoms of schizophrenia were measured with the Positive and Negative Syndrome Scale (PANSS). A linear regression controlling for confounding factors was performed. 70 subjects were included, 35 patients, and 35 controls matched for sex and age. Patients with schizophrenia presented a significantly lower macular volume (p < 0.05) and thickness (< 0.05) than controls. PANSS positive, general and total scores were associated with retinal nerve fiber layer (RNFL) thickness (p < 0.05). There was no association between inflammatory markers (CRP and IL-6) levels and the retinal layer. A reduction in macular volume and thickness was found in patients with schizophrenia. The severity of schizophrenia symptoms was associated with RNFL thickness. CRP and IL-6 are not associated with retinal thickness/volume in schizophrenia or controls.

The moderating effect of cognitive impairment on the relationship between inner speech and auditory verbal hallucinations among chronic patients with schizophrenia.

BACKGROUND: Even though there is an increasing amount of evidence from behavioral and neuroimaging studies to suggest that pathological inner speech plays a role in the emergence of auditory verbal hallucinations (AVH), studies investigating the mechanisms underlying this relationship are rather scarce. Examining moderators might inform the development of new treatment options for AVH. We sought to extend the existing knowledge by testing the moderating role of cognitive impairment in the association between inner speech and hallucinations in a sample of Lebanese patients with schizophrenia. METHODS: A cross-sectional study was conducted from May till August 2022, enrolling 189 chronic patients. RESULTS: Moderation analysis revealed that, after controlling for delusions, the interaction of experiencing voices of other people in inner speech by cognitive performance was significantly associated with AVH. In people having low (Beta = 0.69; t = 5.048; p < .001) and moderate (Beta = 0.45; t = 4.096; p < .001) cognitive performance, the presence of voices of other people in inner speech was significantly associated with more hallucinations. This association was not significant in patients with high cognitive function (Beta = 0.21; t = 1.417; p = .158). CONCLUSION: This preliminarily study suggests that interventions aiming at improving cognitive performance may also have a beneficial effect in reducing hallucinations in schizophrenia.

Visuospatial ability and attention as risk factors for suicidal ideation in middle-aged and elderly schizophrenia patients: a cross-sectional study.

BACKGROUND: Schizophrenia patients have a high risk of suicide, and their cognition function is impaired with increasing age. The association between neurocognitive and suicidality in schizophrenia patients are heterogeneous. We aimed to explore the relationship between neurocognitive function and suicidal ideation in schizophrenia patients across age groups. METHODS: A total of 587 patients with schizophrenia were enrolled in this study. The schizophrenia patients were divided into young group (aged 18-44) and middle-aged and elderly group (aged 45-70). The schizophrenia patients were divided into suicidal ideation group and non-suicidal ideation group according to the evaluation results of the Beck Scale for Suicide Ideation. Insomnia symptoms were measured by the Insomnia Severity Index (ISI). Psychotic symptoms were measured by the Positive and Negative Syndrome Scale (PANSS), and cognitive function was measured by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). RESULTS: There was a negative correlation between the age and attention scores of RBANS (P = 0.018). The young schizophrenia patients had higher risk of suicidality than middle-aged and elderly schizophrenia patients (P = 0.001). In the logistic regression analysis, the scores of ISI and positive symptoms scores of PANSS were associated with suicidal ideation among young schizophrenia patients (All P < 0.05). Age, BMI, the scores of ISI, general symptoms scores of PANSS, visuospatial scores of RBANS and attention scores of RBANS were associated with suicidal ideation in middle-aged and elderly schizophrenia patients (All P < 0.05). CONCLUSIONS: High visuospatial scores of RBANS and attention scores of RBANS were risk factors for suicidal ideation in middle-aged and elderly schizophrenia patients.

Autobiographical memory and the self on the psychosis continuum: investigating their relationship with positive- and negative-like symptoms.

Autobiographical memory is severely impaired in schizophrenia, but previous work has largely treated both as unitary concepts. Here, we examined how various dimensions of autobiographical memory relate to different aspects of psychosis. Participants were recruited from the general population (Study 1, N = 264) and a university subject pool (Study 2, N = 305). We examined different measures of autobiographical memory and self (i.e., involuntary memory, autobiographical recollection, self-knowledge and self-awareness), at the trait level in Study 1 and both trait and state levels in Study 2, as a function of positive-and negative-like symptoms of psychosis. Across both studies, positive and negative dimensions of psychosis were found to be related to an increase in involuntary memories (i.e., the spontaneous recall of personal memories), and to lower self-concept clarity and insight. Positive and negative dimensions of psychosis correlated differently with autobiographical recollection characteristics, measured at both trait (Studies 1 and 2) and state levels (Study 2). Positive-like symptoms (in particular hallucination-proneness) showed a stronger and more consistent pattern of correlations than negative-like symptoms. These findings call for a dimensional approach to the relationship between autobiographical memory and psychosis symptoms in clinical and non-clinical individuals, to better understand the breakdown of autobiographical memory in the psychopathology of psychosis.

"Feeling shattered and ephemeral": How do positive and negative symptoms affect self-concept clarity among individuals experiencing psychosis?

PURPOSE: Incoherence in sense of self in schizophrenia may mask individuals' ability to perceive reality accurately, and cause them to feel alienated from themselves and others. This descriptive correlational study investigates the relationship between positive and negative symptoms in relation to self-concept clarity (SCC) in schizophrenia. METHOD: A sample of 200 inpatients with schizophrenia were recruited to complete the Self-Concept Clarity Scale and were rated on the Brief Psychiatric Rating Scale (BPRS-version 4.0). RESULTS: A strong inverse correlation between positive and negative symptoms in relation to SCC (r = 0.242, P < 0.001, and r = 0.225, P = 0.001, respectively). CONCLUSION: The overall BPRS scores were identified as independent precursors of low SCC.

Metacognitive mastery moderates the relationship between positive symptoms and distress in adults with serious mental illness.

BACKGROUND: Research supports the possibility that a person's metacognitive ability may influence the impact of positive symptoms. This connection is important because understanding how metacognitive capacity relates to positive symptoms and distress can guide treatment and bolster recovery. AIMS: To explore this, we assessed the moderating role of Metacognitive Mastery on the relationship of positive symptoms to affective symptoms, or markers of distress, measured both concurrently and at a later time point (to assess durability of metacognition) with persons with serious mental illness. To rule out the possibility that any findings were the result of cognitive impairments or general psychopathology we included measures of neurocognition and symptoms as potential covariates. METHODS: Participants were 67 individuals with the majority diagnosed with either schizophrenia spectrum disorder, major depressive disorder, or bipolar disorder. Metacognition was measured with the Metacognitive Assessment Scale-Abbreviated, symptoms were measured using the Brief Psychiatric Rating Scale and verbal memory was measured using the California Verbal Learning Test. RESULTS: Metacognitive Mastery moderated the relationship between positive symptoms and affective symptoms at both time points with differential patterns at each point. CONCLUSIONS: Metacognitive Mastery may exert a complex influence upon the effects of positive symptoms on distress.

Clinical insight in first episode psychosis: the role of metacognition.

BACKGROUND: Poor clinical insight has been commonly reported in those with First Episode Psychosis (FEP) and thought to be influenced by a range of factors, including neurocognition and symptoms. Clinical insight may be compromised as a result of alterations in higher-level reflective processes, such as metacognitive ability and cognitive insight. AIMS: To explore whether metacognitive ability and cognitive insight are associated with clinical insight while controlling for IQ, depression, and symptoms in FEP. METHODS: 60 individuals with FEP completed measures for clinical insight, metacognitive ability, cognitive insight, positive and negative symptoms, depression, and IQ. RESULTS: Higher levels of metacognitive ability were associated with better clinical insight, even when controlling for IQ, depression, positive and negative symptoms, and medication. Integration subscale of metacognitive ability was most strongly associated with clinical insight. Cognitive insight was associated with clinical insight when controlling for covariates. However, when including metacognitive ability and cognitive insight in the predictive model, only metacognitive ability was significantly related to clinical insight. DISCUSSION: Metacognitive ability, specifically the ability to describe one's evolving mental state to provide a coherent narrative, was significantly related to clinical insight, independent of covariates, and may be a potentially important target for intervention in FEP.

Adolescent nicotine potentiates the inhibitory effect of raclopride, a D2R antagonist, on phencyclidine-sensitized psychotic-like behavior in mice.

The association between schizophrenia and nicotine addiction becomes evident during adolescence. Here, to investigate interactive events that might underlie the early establishment of this comorbidity, we used phencyclidine-evoked locomotor sensitization, a proxy model of psychotic behavior, and nicotine minipump infusions in adolescent mice. Considering the involvement of dopamine D2 receptors in both schizophrenia and addiction, we further tested their role by exposing mice to raclopride. Adolescent mice that were either exposed to nicotine (24 mg/Kg/day) or not, received single daily raclopride (0.5 mg/kg, s.c.) or saline followed by phencyclidine injections (10 mg/Kg, s.c.) during open field testing for 6 consecutive days (Acquisition phase, ACQ). Phencyclidine and nicotine challenges (Sensitization Test, ST) were carried out after a 5-day withdrawal. Ambulation escalated in response to repeated phencyclidine exposure during ACQ and was increased after phencyclidine challenge, evidencing development and expression of locomotor sensitization. Raclopride prevented phencyclidine-evoked development of sensitization. However, raclopride pre-exposure during ACQ only shortened its expression in phencyclidine-challenged mice. Nicotine failed to interfere with phencyclidine stimulatory effects during ACQ but potentiated raclopride inhibition during the first ACQ days. During ST, nicotine history shortened the expression of phencyclidine-evoked sensitization. Nicotine challenge had no impact on locomotion, which is consistent with a lack of nicotine/phencyclidine cross-sensitization. In conclusion, our results show that nicotine does not worsen, and may even ameliorate phencyclidine-sensitized psychotic-like behavior in adolescent mice. The potentiation of raclopride-mediated inhibition further suggests that nicotine transiently improves the therapeutic efficacy of medication on psychotic symptoms through mechanisms that converge on D2 receptors.

Real-time cognitive performance and positive symptom expression in schizophrenia.

Deficits in cognitive functions are frequent in schizophrenia and are often conceptualized as stable characteristics of this disorder. However, cognitive capacities may fluctuate over the course of a day and it is unknown if such variation may be linked to the dynamic expression of psychotic symptoms. This investigation used Ecological Momentary Assessment (EMA) to provide mobile tests of cognitive functions and positive symptoms in real time. Thirty-three individuals with schizophrenia completed five EMA assessments per day for a one-week period that included real-time assessments of cognitive performance and psychotic symptoms. A subsample of patients and 31 healthy controls also completed a functional MRI examination. Relative to each individual's average score, moments of worsened cognitive performance on the mobile tests were associated with an increased probability of positive symptom occurrence over subsequent hours of the day (coef = 0.06, p < 0.05), adjusting for the presence of psychotic symptoms at the moment of mobile test administration. These prospective associations varied as a function of graph theory indices in MRI analyses. These findings demonstrate that cognitive performance is prospectively linked to psychotic symptom expression in daily life, and that underlying brain markers may be observed in the Executive Control Network. While the potential causal nature of this association remains to be investigated, our results offer promising prospects for a better understanding of the underlying mechanisms of symptom expression in schizophrenia.

Relationship between neurocognition and theory of mind as a function of symptomatic profile in schizophrenia: results from the national FACE-SZ cohort.

INTRODUCTION: Deficits in theory of mind (ToM) can vary depending on the predominant schizophrenia symptoms, and though most neurocognitive functions are involved in ToM, all may not be associated with the same symptoms. With consideration to the relationships between symptoms, neurocognition and ToM, the aim of the present study is to identify the neurocognitive functions influencing ToM capacities according to symptomatic profile. METHODS: The study is based on a sample of 124 adults with schizophrenia from a French national cohort. Patients were divided into two groups according to their scores on the five Wallwork factors of the Positive and Negative Syndrome Scale using hierarchical clustering before carrying out multivariable analyses. RESULTS: The "disorganised group" (n = 89) showed high scores on the disorganised factor, and had a ToM associated with reasoning, visual recognition and speed of processing. The "positive group" (n = 35) showed high scores on the positive and depressive factors, and had a ToM associated with working memory. CONCLUSIONS: These results suggest that neurocognitive predictors of ToM in schizophrenia are different according to the predominant clinical dimension, thus refining our knowledge of the relationship between symptoms, neurocognition and ToM, and acknowledging their status as important predictors of patients' functional status.

Aberrant salience correlates with psychotic dimensions in outpatients with schizophrenia spectrum disorders.

BACKGROUND: Aberrant salience is a well-known construct associated with the development and maintenance of psychotic symptoms in schizophrenia. However, only a few studies have investigated aberrance salience as a trait, with no study investigating the association between the five aberrant salience domains and psychotic symptoms. We aimed to explore the role of aberrant salience and its domains on psychotic dimensions in both clinically remitted and non-remitted patients. METHODS: A sample of 102 patients diagnosed with schizophrenia spectrum disorders was divided according to the Positive and Negative Syndrome Scale (PANSS) remission criteria into two groups: remitted and non-remitted. Differences regarding psychotic symptomatology assessed by the PANSS and aberrant salience measured by the Aberrant Salience Inventory (ASI) were explored. Finally, a correlation analysis between the PANSS and the ASI was run. RESULTS: Significantly higher ASI scores were evident among non-remitted patients. Positive symptoms (i.e. delusions, conceptual disorganization, and hallucinatory behaviour) and general psychopathology (i.e. postural mannerisms, unusual thought content) were correlated to the aberrant salience subscales 'sharpening of senses', 'heightened emotionality' and 'heightened cognition' and with the ASI total score. Significant correlations emerged between negative symptoms (blunted affect and social withdrawal) and 'heightened cognition'. Finally, lack of spontaneity of conversation was related to the subscales 'heightened emotionality' and 'heightened cognition', as well as to the ASI total score. CONCLUSIONS: These preliminary results support the hypothesis of an association between aberrant salience and psychotic symptoms in schizophrenia. Further research is needed, especially into the mechanisms underlying salience processing, in addition to social and environmental factors and cognitive variables.