The impact of inflammation on neurocognition and risk for psychosis: a critical review

Development of an anti-inflammatory diet for first-episode psychosis (FEP): a feasibility study protocol

Background

Evidence suggests inflammation plays a role in the pathophysiology of psychosis even in early illness, indicating a potential avenue for anti-inflammatory interventions that simultaneously address high rates of metabolic disease in this population. The aim of this study is to design a novel anti-inflammatory diet intervention (DI) that is feasible to implement in a first-episode psychosis (FEP) population.

Methods

Eligible FEP Participants are aged 15-30. The DI is currently being refined through a multi-phase process that includes the recruitment of focus groups that provide insight into feasibility of measures and nutritional education, as well as the implementation of the DI. The phases in the study are the Development Phase, Formative Phase, and the Feasibility Phase.

Results

The Development phase has resulted in the creation of a flexible DI for FEP based on existing research on nutritional health and informed by providers. This study has just completed the Formative phase, recruiting eligible participants to join focus groups that gleaned information about dietary habits, preferences, and food environments to further refine the DI.

Conclusion

Findings from earlier phases have advised the current Feasibility Phase in which this novel DI is being administered to a small cohort of FEP participants (N = 12) to determine acceptability of the DI from a lived experience perspective. Naturalistic changes in inflammatory biomarkers, metabolic health, and symptoms will also be measured.

Cognitive and inflammatory heterogeneity in severe mental illness: Translating findings from blood to brain

Recent findings link cognitive impairment and inflammatory-immune dysregulation in schizophrenia (SZ) and bipolar (BD) spectrum disorders. However, heterogeneity and translation between the periphery and central (blood-to-brain) mechanisms remains a challenge. Starting with a large SZ, BD and healthy control cohort (n = 1235), we aimed to i) identify candidate peripheral markers (n = 25) associated with cognitive domains (n = 9) and elucidate heterogenous immune-cognitive patterns, ii) evaluate the regulation of candidate markers using human induced pluripotent stem cell (iPSC)-derived astrocytes and neural progenitor cells (n = 10), and iii) evaluate candidate marker messenger RNA expression in leukocytes using microarray in available data from a subsample of the main cohort (n = 776), and in available RNA-sequencing deconvolution analysis of postmortem brain samples (n = 474) from the CommonMind Consortium (CMC). We identified transdiagnostic subgroups based on covariance between cognitive domains (measures of speed and verbal learning) and peripheral markers reflecting inflammatory response (CRP, sTNFR1, YKL-40), innate immune activation (MIF) and extracellular matrix remodelling (YKL-40, CatS). Of the candidate markers there was considerable variance in secretion of YKL-40 in iPSC-derived astrocytes and neural progenitor cells in SZ compared to HC. Further, we provide evidence of dysregulated RNA expression of genes encoding YKL-40 and related signalling pathways in a high neuroinflammatory subgroup in the postmortem brain samples. Our findings suggest a relationship between peripheral inflammatory-immune activity and cognitive impairment, and highlight YKL-40 as a potential marker of cognitive functioning in a subgroup of individuals with severe mental illness.

Placental inflammatory cytokines mRNA expression and preschool children's cognitive performance: a birth cohort study in China

BACKGROUND

The immunologic milieu at the maternal-fetal interface has profound effects on propelling the development of the fetal brain. However, accessible epidemiological studies concerning the association between placental inflammatory cytokines and the intellectual development of offspring in humans are limited. Therefore, we explored the possible link between mRNA expression of inflammatory cytokines in placenta and preschoolers' cognitive performance.

METHODS

Study subjects were obtained from the Ma'anshan birth cohort (MABC). Placental samples were collected after delivery, and real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to measure the mRNA expression levels of IL-8, IL-1β, IL-6, TNF-α, CRP, IFN-γ, IL-10, and IL-4. Children's intellectual development was assessed at preschool age by using the Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Multiple linear regression and restricted cubic spline models were used for statistical analysis.

RESULTS

A total of 1665 pairs of mother and child were included in the analysis. After adjusting for confounders and after correction for multiple comparisons, we observed that mRNA expression of IL-8 (β =  - 0.53; 95% CI, - 0.92 to - 0.15), IL-6 (β =  - 0.58; 95% CI, - 0.97 to - 0.19), TNF-α (β =  - 0.37; 95% CI, - 0.71 to - 0.02), and IFN-γ (β =  - 0.31; 95% CI, - 0.61 to - 0.03) in the placenta was negatively associated with preschoolers' full scale intelligence quotient (FSIQ). Both higher IL-8 and IL-6 were associated with lower children's low fluid reasoning index (FRI), and higher IFN-γ was associated with lower children's working memory index (WMI). After further adjusting for confounders and children's age at cognitive testing, the integrated index of six pro-inflammatory cytokines (index 2) was found to be significantly and negatively correlated with both the FSIQ and each sub-dimension (verbal comprehension index (VCI), visual spatial index (VSI), FRI, WMI, processing speed index (PSI)). Sex-stratified analyses showed that the association of IL-8, IFN-γ, and index 2 with children's cognitive development was mainly concentrated in boys.

CONCLUSIONS

Evidence of an association between low cognitive performance and high expression of placental inflammatory cytokines (IL-8, IL-6, TNF-α, and IFN-γ) was found, highlighting the potential importance of intrauterine placental immune status in dissecting offspring cognitive development.

Factors Associated with Symptom Persistence in PANS: Part II-Presenting Features, Medical Comorbidities, and IVIG Treatment History

Objective: Individuals with Pediatric Acute Onset Neuropsychiatric Syndrome (PANS) experience neuropsychiatric symptoms following an infection or other trigger. Although PANS is typically described as relapsing-remitting, a large community-based 2017 study revealed a range of courses. The present study examined clinical predictors of symptom persistence, measured as % days symptom-free, in this same sample. Methods: A 146-question online survey gathered histories (infections and other triggers, medical and developmental comorbidities), symptomatology, interventions, and outcomes (including school functioning) of PANS patients. Multivariate analyses were applied to examine associations between these variables and % days symptom-free across the disease course. Results: Among the 646 subjects included, significant relationships were found between greater symptom persistence and higher rates of medical comorbidities (especially rashes, headaches, chronic sinusitis, frequent diarrhea, and immune deficiencies), developmental diagnoses, and respondent-perceived developmental lags. Subjects with greater symptom persistence were significantly more likely to report PANS exacerbations associated with infections in close contacts, vaccinations, environmental triggers, and exacerbations of comorbidities and were more likely to report PANS recurrences triggered by Epstein Barr Virus, mycoplasma, and sinus infections. More persistent PANS was also associated with significantly higher frequencies of certain symptoms (sleep disturbance, urinary incontinence, muscle pain, brain fog, sensory defensiveness, irritability, and aggression-related symptoms), less effectiveness of intravenous immunoglobulin in combating symptoms, and more difficulty attending school. Conclusions: Our results suggest high symptom persistence in PANS to be associated with more pervasive medical and neuropsychiatric symptoms. Differences in symptom persistence are associated with both intrinsic (e.g., immune competence) and extrinsic (e.g., infections, treatment) factors. Because extrinsic factors are potentially modifiable, it is critical that providers be aware of current guidelines on PANS evaluation and treatment.

Importance of the dysregulation of the kynurenine pathway on cognition in schizophrenia: a systematic review of clinical studies

Schizophrenia is a chronic psychotic disease burdened by cognitive deficits which hamper daily functioning causing disability and costs for society. Biological determinants underlying cognitive impairment are only partially understood and there are no convincing pharmacological targets able to improve cognitive outcome. Mounting evidence has shown the involvement of the kynurenine pathway in the pathophysiology of schizophrenia, also concerning cognitive symptoms. Therefore, the action of specific metabolites of kynurenine could affects cognition in schizophrenia. To evaluate the impact of the metabolites of kynurenine pathway on cognitive functions in schizophrenia spectrum disorders, with a focus on the modulating role of gender, to identify predictors of cognitive functioning and hypothetical pharmacological targets able to resize disability by improving cognition, thus functioning and quality of life. A systematic review was performed in PubMed/MEDLINE and Embase according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. All studies measuring the direct impact of kynurenine metabolites on cognitive performances in living individuals with schizophrenia spectrum disorders were included in the review. Six studies were included. The activation of the kynurenine pathway resulted associated with greater cognitive deficits in patients with schizophrenia and both elevations and reduction of metabolites seemed able to affect cognitive outcome. No modulating role of sex emerged. This systematic review provides evidence that the activation of the kynurenine pathway affects cognition in patients with schizophrenia and highlights this pathway as a possible future target for developing novel drugs toward this still unmet clinical need. However, evidence is still limited and future studies are needed to further clarify the relationship between kynurenine pathway and cognition in schizophrenia.

Rethinking Immunity and Cognition in Clinical High Risk for Psychosis

It is well known that schizophrenia is associated with cognitive impairment, reduced cortical grey matter and increased circulating concentrations of inflammatory cytokines. However, the relationship between these findings is not clear. We outline the influential neuroinflammatory hypotheses that raised cytokines provoke a damaging immune response in microglia that results in reduced grey matter and associated cognitive performance. We investigated whether such an interaction might be detectable in the prodromal period as illness emerges from the Clinical High Risk for Psychosis (CHR-P). Meta-analyses suggest that compared with controls, impaired cognition and reduced grey matter are already present by the prodrome and that greater decrements are present in those who later develop symptoms. In contrast, the few cytokine studies report no abnormalities in CHR-P except that interleukin-6 (IL-6) levels were raised versus controls and to a greater extent in the future patients, in one study. We noted that cognitive impairment and less cortical grey matter are more severe in schizophrenia than in affective disorders, but that increased cytokine levels are similarly prevalent across disorders. We found no studies correlating cytokine levels with cognitive impairment in CHR-P but such correlations seem unlikely given the minimal relationship reported in a recent meta-analysis of the many cytokine-cognition studies in established illness. From this and other evidence, we conclude that neuroinflammation is not a core feature of schizophrenia nor a substrate for reduced grey matter volume or cognitive function. We draw attention instead to the emerging evidence that brain-resident immune cells and signalling molecules such as Tregs and IL-6, which are influenced by schizophrenia risk genes, regulate and are necessary for the development and function of neuron-glia interaction. We suggest that cognitive impairment in schizophrenia can be seen as a convergence of genetic and immune-neurodevelopmental dysregulation whereas raised cytokines are a consequence of impaired Tregs control of systemic inflammation.

Cognitive impairment in psychiatric diseases: Biomarkers of diagnosis, treatment, and prevention

Psychiatric diseases, such as schizophrenia, bipolar disorder, autism spectrum disorder, and major depressive disorder, place a huge health burden on society. Cognitive impairment is one of the core characteristics of psychiatric disorders and a vital determinant of social function and disease recurrence in patients. This review thus aims to explore the underlying molecular mechanisms of cognitive impairment in major psychiatric disorders and identify valuable biomarkers for diagnosis, treatment and prevention of patients.

Association between Peripheral Inflammatory Cytokines and Cognitive Function in Patients with First-Episode Schizophrenia

In this study, we investigated the impact of inflammatory cytokines on the cognitive performance of patients with schizophrenia. The included patients met the criteria for schizophrenia spectrum disorder and were aged between 15 and 40 years, with a duration of illness ≤1 year. Plasma tumor necrosis factor (TNF)-α; interferon-γ; and interleukin (IL)-1β, IL-6, IL-8, IL-10, and IL-12 levels were measured. A computerized neurocognitive battery, measures for social cognitive function, and clinical measures were administered. A total of 174 patients with first-episode psychosis were enrolled. The TNF-α level was negatively correlated with scores on the digit span, verbal learning, and Wisconsin card sorting tests, and the number of correct responses on the continuous performance test (CR-CPT), whereas a positive correlation was detected with the trail making test (TMT)-B time. The interferon-γ level was negatively correlated with performance on the false belief and visual learning tests. The IL-1β level was positively correlated with the TMT-A time and CPT reaction time, whereas it was negatively correlated with the CR-CPT and performance on the visual learning and social cognitive tests. The IL-12 level was negatively correlated with the CR-CPT and false belief test. Our results suggest that proinflammatory cytokines are associated with cognitive impairment in patients with schizophrenia.

Immune–Inflammatory Biomarkers Predict Cognition and Social Functioning in Patients With Type 2 Diabetes Mellitus, Major Depressive Disorder, Bipolar Disorder, and Schizophrenia: A 1-Year Follow-Up Study

Background

Systemic, low-grade immune–inflammatory activity, together with social and neurocognitive performance deficits are a transdiagnostic trait of people suffering from type 2 diabetes mellitus (T2DM) and severe mental illnesses (SMIs), such as schizophrenia (SZ), major depressive disorder (MDD), and bipolar disorder (BD). We aimed to determine if immune–inflammatory mediators were significantly altered in people with SMIs or T2DM compared with healthy controls (HC) and whether these biomarkers could help predict their cognition and social functioning 1 year after assessment.

Methods

We performed a prospective, 1-year follow-up cohort study with 165 participants at baseline (TB), including 30 with SZ, 42 with BD, 35 with MDD, 30 with T2DM, and 28 HC; and 125 at 1-year follow-up (TY), and determined executive domain (ED), global social functioning score (GSFS), and peripheral blood immune–inflammatory and oxidative stress biomarkers.

Results

Participants with SMIs and T2DM showed increased peripheral levels of inflammatory markers, such as interleukin-10 (p < 0.01; η²p = 0.07) and tumor necrosis factor-α (p < 0.05; η²p = 0.08); and oxidative stress biomarkers, such as reactive oxygen species (ROS) (p < 0.05; η²p = 0.07) and mitochondrial ROS (p < 0.01; η²p = 0.08). The different combinations of the exposed biomarkers anticipated 46–57.3% of the total ED and 23.8–35.7% of GSFS for the participants with SMIs.

Limitations

Participants' treatment, as usual, was continued without no specific interventions; thus, it was difficult to anticipate substantial changes related to the psychopharmacological pattern.

Conclusion

People with SMIs show significantly increased levels of peripheral immune–inflammatory biomarkers, which may contribute to the neurocognitive and social deficits observed in SMIs, T2DM, and other diseases with systemic immune–inflammatory activation of chronic development. These parameters could help identify the subset of patients who could benefit from immune–inflammatory modulator strategies to ameliorate their functional outcomes.

The Neutrophil-Lymphocyte Ratio Is Positively Correlated with Aggression in Schizophrenia

To find biomarkers to assess the risk of aggression, we looked at the association between aggression and levels of body inflammation in patients with schizophrenia. The Modified Overt Aggression Scale (MOAS) score was used to divide the aggressive (n = 72) and nonaggressive (n = 141) groups. The Brief Psychiatric Rating Scale (BPRS) is a tool for determining the severity of a patient's condition. After measuring the number of inflammatory cells in the peripheral blood, the platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), and monocyte-lymphocyte ratio (MLR) were estimated. We investigated the relationship between aggressive behavior, bodily inflammation, and BPRS. Before therapy, the aggressive group's BPRS score, white blood cell (WBC) count, neutrophil count, monocyte count, NLR, and MLR were considerably more significant than the nonaggressive group's. After therapy, statistically significant variations in total BPRS score and neutrophil count between the two groups. According to correlation analysis before and after treatment, aggressive behavior was positively connected with neutrophil count, NLR, and BPRS score. The presence of aggressive behavior in schizophrenic patients indicates the severity of the disorder to some degree. NLR can be used as an objective biomarker to quickly assess the risk of aggression in schizophrenic patients.

The Effects of Peripheral Inflammation on the Brain-A Neuroimaging Perspective

In the field of neuropsychiatry, neuroinflammation is one of the prevailing hypotheses to explain the pathophysiology of mood and psychotic disorders. Neuroinflammation encompasses an ill-defined set of pathophysiological processes in the central nervous system that cause neuronal or glial atrophy or death and disruptions in neurotransmitter signaling, resulting in cognitive and behavioral changes. Positron emission tomography for the brain-based translocator protein has been shown to be a useful tool to measure glial activation in neuropsychiatric disorders. Recent neuroimaging studies also indicate a potential disruption in the choroid plexus and blood-brain barrier, which modulate the transfer of ions, molecules, toxins, and cells from the periphery into the brain. Simultaneously, peripheral inflammatory markers have consistently been shown to be altered in mood and psychotic disorders. The crosstalk (i.e., the communication between peripheral and central inflammatory pathways) is not well understood in these disorders, however, and neuroimaging studies hold promise to shed light on this complex process. In the current Perspectives article, we discuss the neuroimaging insights into neuroimmune crosstalk offered in selected works. Overall, evidence exists for peripheral immune cell infiltration into the central nervous system in some patients, but the reason for this is unknown. Future neuroimaging studies should aim to extend our knowledge of this system and the role it likely plays in symptom onset and recurrence.

Is psychosis a syndemic manifestation of historical and contemporary adversity? Findings from UK Biobank

BACKGROUND

Psychosis is associated with many forms of adversity, deprivation and living in urban areas.

AIMS

To investigate whether psychosis is part of a syndemic of multiple adversities.

METHOD

Drawing on UK Biobank (UKBB) data (Project ID: 57601), we sought to understand mechanisms by which childhood, recent/contemporary and place-based adversities might cluster and interact to be implicated in pathways by which psychoses evolve. We investigated the associations between adversities, potential mediating inflammatory markers and ICD-10 diagnoses (F20-F31) of psychotic disorders. We fitted logistic regression models initially including all relevant candidate variables and used backwards deletion to retain theoretically plausible and statistically significant (P < 0.05) associations with psychotic disorders. The candidate variables were entered in a partial least squares structural equation model (PLS-SEM) to test for syndemic interactions between risk factors. We tested whether the findings were sensitive to demographics, gender and ethnicity.

RESULTS

We fitted a PLS-SEM including psychosis as a syndemic outcome, and identified three latent constructs: lifetime adversity, current adversity and biomarkers. Factor loadings were above 0.30, and all structural paths were significant (P < 0.05). There were moderate associations between lifetime adversity and current adversity (standardised coefficient s.c. = 0.178) and between current adversity and biomarkers (s.c. = 0.227). All three latent constructs showed small but significant associations with psychosis (s.c. < 0.04). Lifetime adversity and current adversity were more strongly associated among ethnic minorities (combined) than White British people.

CONCLUSIONS

Our findings stress the importance of interactions between childhood and contemporary adversities in preventive and therapeutic interventions for psychotic disorders, especially among ethnic minorities.

Increased peripheral inflammation in schizophrenia is associated with worse cognitive performance and related cortical thickness reductions

While the biological substrates of brain and behavioural changes in persons with schizophrenia remain unclear, increasing evidence implicates that inflammation is involved. In schizophrenia, including first-episode psychosis and anti-psychotic naïve patients, there are numerous reports of increased peripheral inflammation, cognitive deficits and neuropathologies such as cortical thinning. Research defining the relationship between inflammation and schizophrenia symptomatology and neuropathology is needed. Therefore, we analysed the level of C-reactive protein (CRP), a peripheral inflammation marker, and its relationship with cognitive functioning in a cohort of 644 controls and 499 schizophrenia patients. In a subset of individuals who underwent MRI scanning (99 controls and 194 schizophrenia cases), we tested if serum CRP was associated with cortical thickness. CRP was significantly increased in schizophrenia patients compared to controls, co-varying for age, sex, overweight/obesity and diabetes (p < 0.006E-10). In schizophrenia, increased CRP was mildly associated with worse performance in attention, controlling for age, sex and education (R =- 0.15, p = 0.001). Further, increased CRP was associated with reduced cortical thickness in three regions related to attention: the caudal middle frontal, the pars opercularis and the posterior cingulate cortices, which remained significant after controlling for multiple comparisons (all p < 0.05). Together, these findings indicate that increased peripheral inflammation is associated with deficits in cognitive function and brain structure in schizophrenia, especially reduced attention and reduced cortical thickness in associated brain regions. Using CRP as a biomarker of peripheral inflammation in persons with schizophrenia may help to identify vulnerable patients and those that may benefit from adjunctive anti-inflammatory treatments.

Postnatal Antioxidant and Anti-inflammatory Treatments Prevent Early Ketamine-Induced Cortical Dysfunctions in Adult Mice

Early brain insult, interfering with its maturation, may result in psychotic-like disturbances in adult life. Redox dysfunctions and neuroinflammation contribute to long-term psychiatric consequences due to neurodevelopmental abnormalities. Here, we investigated the effects of early pharmacological modulation of the redox and inflammatory states, through celastrol, and indomethacin administration, on reactive oxygen species (ROS) amount, levels of malondialdehyde (MDA) and antioxidant enzymes (superoxide dismutase 1, SOD1, glutathione, GSH, and catalase, CAT), as well as of pro-inflammatory cytokines (tumor necrosis factor-alpha, TNF-α, interleukin-6, IL-6, and interleukin-1 beta, IL-1β), in the prefrontal cortex of adult mice exposed to a neurotoxic insult, i.e. ketamine administration, in postnatal life. Early celastrol or indomethacin prevented ketamine-induced elevations in cortical ROS production. MDA levels in ketamine-treated mice, also administered with celastrol, were comparable with the control ones. Indomethacin also prevented the increase in lipid peroxidation following early ketamine administration. Whereas no significant differences were detected in SOD1, GSH, and CAT levels between ketamine and saline-administered mice, celastrol elevated the cortical amount of these antioxidant enzymes and the same effect was induced by indomethacin per se. Both celastrol and indomethacin prevented ketamine-induced enhancement in TNF-α and IL-1β levels, however, they had no effects on increased IL-6 amount resulting from ketamine exposure in postnatal life. In conclusion, our data suggest that an early increase in cortical ROS scavenging and reduction of lipid peroxidation, via the enhancement of antioxidant defense, together with inhibition of neuroinflammation, may represent a therapeutic opportunity against psychotic-like disturbances resulting, later in life, from the effects of a neurotoxic insult on the developing brain.

Predictors of cognitive impairment in treatment-resistant depression

BACKGROUND

Cognitive impairment is a well-recognized symptom of major depressive disorder; however, contributing factors are not fully characterized. The present study examined the neurocognitive profiles and predictors of cognitive impairment in patients with treatment-resistant depression (TRD).

METHODS

Moderate to severely depressed TRD patients were compared to matched healthy volunteers (HV) in verbal learning and recall and executive functions. Based on cognitive scores, cluster analysis was performed to identify subsets within the TRD sample. Predictors of cognitive impairment were also investigated.

RESULTS

TRD patients showed worse performance in tests assessing verbal memory, executive attentional shifting, and inhibitory control. The cluster analysis revealed two groups: a cognitively impaired (CI) group that showed a generalized deficit across cognitive domains, and a relatively cognitively intact group that performed better than CI in all domains except attentional shifting. A logistic binomial regression of the two groups revealed three significant contributing risk factors for CI: 1) older age, 2) lower premorbid IQ, and 3) benzodiazepine use. Cognitive impairment and benzodiazepine use were associated with worse functioning.

CONCLUSIONS

Significant cognitive impairment is present in TRD and is associated with worse functioning. Age, lower premorbid IQ, and benzodiazepine use increased the likelihood of generalized cognitive impairment in TRD patients. The detrimental effect of benzodiazepine on cognitive impairment is independent of anxiety symptoms. Further research is needed to characterize the timeline of cognitive impairment in depression.

Basic Symptoms Are Associated With Age in Patients With a Clinical High-Risk State for Psychosis: Results From the PRONIA Study

In community studies, both attenuated psychotic symptoms (APS) and basic symptoms (BS) were more frequent but less clinically relevant in children and adolescents compared to adults. In doing so, they displayed differential age thresholds that were around age 16 for APS, around age 18 for perceptive BS, and within the early twenties for cognitive BS. Only the age effect has previously been studied and replicated in clinical samples for APS. Thus, we examined the reported age effect on and age thresholds of 14 criteria-relevant BS in a patient sample at clinical-high risk of psychosis (N = 261, age 15-40 yrs.), recruited within the European multicenter PRONIA-study. BS and the BS criteria, "Cognitive Disturbances" (COGDIS) and "Cognitive-perceptive BS" (COPER), were assessed with the "Schizophrenia Proneness Instrument, Adult version" (SPI-A). Using logistic regressions, prevalence rates of perceptive and cognitive BS, and of COGDIS and COPER, as well as the impact of social and role functioning on the association between age and BS were studied in three age groups (15-18 years, 19-23 years, 24-40 years). Most patients (91.2%) reported any BS, 55.9% any perceptive and 87.4% any cognitive BS. Furthermore, 56.3% met COGDIS and 80.5% COPER. Not exhibiting the reported differential age thresholds, both perceptive and cognitive BS, and, at trend level only, COPER were less prevalent in the oldest age group (24-40 years); COGDIS was most frequent in the youngest group (15-18 years). Functional deficits did not better explain the association with age, particularly in perceptive BS and cognitive BS meeting the frequency requirement of BS criteria. Our findings broadly confirmed an age threshold in BS and, thus, the earlier assumed link between presence of BS and brain maturation processes. Yet, age thresholds of perceptive and cognitive BS did not differ. This lack of differential age thresholds might be due to more pronounced the brain abnormalities in this clinical sample compared to earlier community samples. These might have also shown in more frequently occurring and persistent BS that, however, also resulted from a sampling toward these, i.e., toward COGDIS. Future studies should address the neurobiological basis of CHR criteria in relation to age.

Improving Cognition via Exercise (ICE): Study Protocol for a Multi-Site, Parallel-Group, Single-Blind, Randomized Clinical Trial Examining the Efficacy of Aerobic Exercise to Improve Neurocognition, Daily Functioning, and Biomarkers of Cognitive Change in Individuals with Schizophrenia

Individuals with schizophrenia (SZ) display cognitive deficits that have been identified as major determinants of poor functioning and disability, representing a serious public health concern and an important target for interventions. At present, available treatments offer only minimal to moderate benefits to ameliorate cognitive deficits. Thus, there remains an urgent need to identify novel interventions to improve cognition in people with SZ. Emerging evidence from animal and basic human research suggests aerobic exercise training (AE) has beneficial effects on cognition. Preliminary findings suggest that AE is efficacious in improving cognitive functioning in SZ, however the extant studies have been limited by small samples, a dearth of information on biologically-relevant covariates, and limited information on impact on daily functioning. Additionally, while AE-related cognitive benefits have been linked to Brain-Derived Neurotrophic Factor (BDNF) upregulation, this putative mechanism needs confirmation. The present report describes a study protocol designed to address these limitations-we review and summarize the current literature on treatment of cognitive deficits in SZ, state the rationale for employing AE to target these deficits, and describe the current protocol-a multi-site, single-blind, randomized clinical trial aiming to recruit 200 community-dwelling individuals with SZ. Participants are randomized to one of two 12-week interventions: AE using active-play video games (i.e., Xbox Kinect) and traditional cardiovascular exercise equipment or a stretching-and-toning (ST) control intervention. Participants undergo assessments of aerobic fitness, cognition, and daily functioning, as well as BDNF and other biomarkers of cognitive change, at baseline and after 6-and 12-weeks.