CHR Individuals Research Articles

Unique Functional Neuroimaging Signatures of Genetic Versus Clinical High Risk for Psychosis

Background22q11.2 deletion syndrome (22qDel) is a copy number variant that is associated with psychosis and other neurodevelopmental disorders. Adolescents who are at clinical high risk for psychosis (CHR) are identified based on the presence of subthreshold psychosis symptoms. Whether common neural substrates underlie these distinct high-risk populations is unknown. We compared functional brain measures in 22qDel and CHR cohorts and mapped the results to biological pathways. MethodsWe analyzed 2 large multisite cohorts with resting-state functional magnetic resonance imaging data: 1) a 22qDel cohort (n = 164, 47% female) and typically developing (TD) control participants (n = 134, 56% female); and 2) a cohort of CHR individuals (n = 240, 41% female) and TD control participants (n = 149, 46% female) from the NAPLS-2 (North American Prodrome Longitudinal Study-2). We computed global brain connectivity (GBC), local connectivity (LC), and brain signal variability (BSV) across cortical regions and tested case-control differences for 22qDel and CHR separately. Group difference maps were related to published brain maps using autocorrelation-preserving permutation. ResultsBSV, LC, and GBC were significantly disrupted in individuals with 22qDel compared with TD control participants (false discovery rate–corrected q < .05). Spatial maps of BSV and LC differences were highly correlated with each other, unlike GBC. In the CHR group, only LC was significantly altered versus the control group, with a different spatial pattern than the 22qDel group. Group differences mapped onto biological gradients, with 22qDel effects being strongest in regions with high predicted blood flow and metabolism. Conclusions22qDel carriers and CHR individuals exhibited different effects on functional magnetic resonance imaging temporal variability and multiscale functional connectivity. In 22qDel carriers, strong and convergent disruptions in BSV and LC that were not seen in CHR individuals suggest distinct functional brain alterations.

Reduced resting-state gamma-band power correlate with unaltered glutamate + glutamine levels in patients at clinical-high risk of psychosis

IntroductionThere is growing evidence of excitation / inhibition (E/I) balance abnormalities in schizophrenia, which might be associated with abnormal gamma frequency oscillations and glutamate concentrations. However, to the best of our knowledge, only one multimodal study have examined such associations between EEG and metabolite characteristics in patients at clinical-high risk of psychosis (CHR) so far.ObjectivesWe aimed to investigate potential associations between GLX (glutamate + glutamine) levels and resting-state gamma-band power in CHR individuals and healthy controls (HC).MethodsTwenty right-handed male patients (16-27 years, mean age 19.9 ± 2.7) fulfilling CHR criteria and 19 healthy male controls (16-27 years, mean age 21.6 ± 3.6) underwent resting-state EEG (16 leads; 10−20 system) and MR spectroscopy at 3T MRI scanner with voxels of 30×30×30mm located in left and right medial prefrontal cortex. Spectral analysis with estimation of gamma-band power (30-45 Hz) were conducted. MEGA-PRESS acquisitions were analyzed with jMRUi (ver. 5.1 Alpha), levels of GLX were calculated as a ratios to creatine + phosphocreatine (GLX/Cr). Gamma-band (30-45 Hz) spectral power and GLX/Cr were compared between groups. Correlations between EEG and metabolite data were analyzed with regression model including age and chlorpromazine equivalents as covariates.ResultsCompared to healthy controls, patients showed reduced spectral gamma-band power in 6 leads (Table). No alterations in GLX/Cr were detected. Positive correlations between altered gamma-power in all leads (except Cz) and GLX/Cr in left medial prefrontal cortex were revealed in CHR (F3: r=0.51, p=0.006; F8: r=0. 54, p=0.004; C3: r=0.37, p=0.037; Pz: r=0.51, p=0.039; P4: r=0.56, p=0.009). No correlations in HC group were found. Chlorpromazine equivalents did not correlate with GLX/Cr of gamma power in CHR group.Table.Results of between-group comparisons corrected for multiple comparisons Lead CHR Mean±SD HC Mean±SD p -value F Cohen’s d Cohen’s d CI 95%F30.97±0.621.4±0.640.00977.2-0.69-1.22 -0.16F80.84±0.611.45±1.030.00727.8-0.71-1.24 -0.19C30.97±0.551.44±0.640.00269.9-0.79-1.32 -0.27Cz1.03±0.611.42±0.520.00747.7-0.70-1.22 -0.18Pz1.17±0.71.62±0.630.00987.1-0.68-1.2 -0.16P41.04±0.661.53±0.660.00518.5-0.74-1.27 -0.22ConclusionsThe findings suggest that clinical-high risk of psychosis is associated with widespread alterations in resting-state gamma-band power. Positive correlations of such alterations with GLX/Cr and absence of such correlations in HC group are presumably indicative of disturbances in the excitation / inhibition balance in CHR individuals.This study was supported by RFBR grant 19-29-10040Disclosure of InterestNone Declared

Using brain structural neuroimaging measures to predict psychosis onset for individuals at clinical high-risk

Machine learning approaches using structural magnetic resonance imaging (sMRI) can be informative for disease classification, although their ability to predict psychosis is largely unknown. We created a model with individuals at CHR who developed psychosis later (CHR-PS+) from healthy controls (HCs) that can differentiate each other. We also evaluated whether we could distinguish CHR-PS+ individuals from those who did not develop psychosis later (CHR-PS-) and those with uncertain follow-up status (CHR-UNK). T1-weighted structural brain MRI scans from 1165 individuals at CHR (CHR-PS+, n = 144; CHR-PS-, n = 793; and CHR-UNK, n = 228), and 1029 HCs, were obtained from 21 sites. We used ComBat to harmonize measures of subcortical volume, cortical thickness and surface area data and corrected for non-linear effects of age and sex using a general additive model. CHR-PS+ (n = 120) and HC (n = 799) data from 20 sites served as a training dataset, which we used to build a classifier. The remaining samples were used external validation datasets to evaluate classifier performance (test, independent confirmatory, and independent group [CHR-PS- and CHR-UNK] datasets). The accuracy of the classifier on the training and independent confirmatory datasets was 85% and 73% respectively. Regional cortical surface area measures-including those from the right superior frontal, right superior temporal, and bilateral insular cortices strongly contributed to classifying CHR-PS+ from HC. CHR-PS- and CHR-UNK individuals were more likely to be classified as HC compared to CHR-PS+ (classification rate to HC: CHR-PS+, 30%; CHR-PS-, 73%; CHR-UNK, 80%). We used multisite sMRI to train a classifier to predict psychosis onset in CHR individuals, and it showed promise predicting CHR-PS+ in an independent sample. The results suggest that when considering adolescent brain development, baseline MRI scans for CHR individuals may be helpful to identify their prognosis. Future prospective studies are required about whether the classifier could be actually helpful in the clinical settings.

Reduced slow wave density is associated with worse positive symptoms in clinical high risk: An objective readout of symptom severity for early treatment interventions?

Individuals at clinical high risk for psychosis (CHR) present subsyndromal psychotic symptoms that can escalate and lead to the transition to a diagnosable psychotic disorder. Identifying biological parameters that are sensitive to these symptoms can therefore help objectively assess their severity and guide early interventions in CHR. Reduced slow wave oscillations (∼1 Hz) during non-rapid eye movement sleep were recently observed in first-episode psychosis patients and were linked to the intensity of their positive symptoms. Here, we collected overnight high-density EEG recordings from 37 CHR and 32 healthy control (HC) subjects and compared slow wave (SW) activity and other SW parameters (i.e., density and negative peak amplitude) between groups. We also assessed the relationships between clinical symptoms and SW parameters in CHR. While comparisons between HC and the entire CHR group showed no SW differences, CHR individuals with higher positive symptom severity (N = 18) demonstrated a reduction in SW density in an EEG cluster involving bilateral prefrontal, parietal, and right occipital regions compared to matched HC individuals. Furthermore, we observed a negative correlation between SW density and positive symptoms across CHR individuals, suggesting a potential target for early treatment interventions.

Kenya Psychosis-Risk Outcomes Study (KePROS): Development of an Accelerated Medicine Partnership Schizophrenia-Aligned Project in Africa.

The Accelerating Medicines Partnership Schizophrenia (AMP SCZ) funds a longitudinal study of 43 research sites across 5 continents to develop tools to stratify developmental trajectories of youth at clinical high risk for psychosis (CHR) and identify homogenous targets for future clinical trials. However, there are no sites in Africa, leaving a critical gap in our knowledge of clinical and biological outcomes among CHR individuals. We describe the development of the Kenya Psychosis-Risk Outcomes Study (KePROS), a 5-year NIH-funded project in Kenya designed to harmonize with AMP SCZ. The study will recruit over 100 CHR and 50 healthy participants and conduct multiple clinical and biomarker assessments over 2 years. Capacity building is a key component of the study, including the construction of an electroencephalography (EEG) laboratory and the upgrading of a local 3 T magnetic resonance imaging (MRI) machine. We detail community recruitment, study methodologies and protocols, and unique challenges with this pioneering research in Africa. This paper is descriptive only. Planned future analyses will investigate possible predictors of clinical outcomes and will be compared to results from other global populations. KePROS will provide the research community with a rich longitudinal clinical and biomarker dataset from an African country in the developing Global South, which can be used alongside AMP SCZ data to delineate CHR outcome groups for future treatment development. Training in mental health assessment and investment in cutting-edge biomarker assessment and other technologies is needed to facilitate the inclusion of African countries in large-scale research consortia.

Adverse outcome analysis in people at clinical high risk for psychosis: results from a 2-year Italian follow-up study.

Since January 2016, the Parma Department of Mental Health (in Italy) developed a specialized care program for Early Intervention (EI) in individuals at Clinical High Risk for Psychosis (CHR-P). As unfavorable outcomes other than transition to psychosis were not systematically reported in the current literature (thereby compromising more sophisticated prognostic stratifications), the aims of this research were (1) to investigate adverse outcome indicators (i.e., service disengagement, psychosis transition, hospitalization, prolonged functioning impairment, prolonged persistence of CHR-P criteria, suicide attempts) in an Italian CHR-P population enrolled within a specialized EI service across a 2-year follow-up period, and (2) to examine their relevant associations with sociodemographic and clinical characteristics of the CHR-P total sample at baseline. All participants were young CHR-P help-seekers aged 12-25years. They completed the "Comprehensive Assessment of At-Risk Mental States" (CAARMS) and the Health of the Nation Outcome Scale (HoNOS). Both univariate and multivariate Cox regression analyses were performed. 164 CHR-P individuals were enrolled in this study. Across the follow-up, 30 (18.0%) dropped out the EI program, 23 (14%) transitioned to psychosis, 24 (14.6%) were hospitalized, 23 (14%) had a prolonged persistence of CHR-P criteria and 54 (47%) showed prolonged impairment in socio-occupational functioning. As almost half of our participants did not functionally remit over time, sustained clinical attention for young CHR individuals people should be offered in the longer term, also to monitor unfavorable outcomes and to improve long-term prognosis.

Cognitive deficits profiles in the first-episode of schizophrenia, clinical high risk of psychosis, and genetically high-risk of psychosis.

Cognitive deficits are core characteristics of schizophrenia, presenting before the emergence of psychotic symptoms. Individuals with a clinical high-risk for psychosis (CHR) and those with genetically high-risk of psychosis (GHR) also exhibit cognitive impairments. Nonetheless, it remains uncertain in which domains of cognitive impairments in these two groups were more similar to those of schizophrenia patients. Moreover, it is unclear which domains of impairment are caused by quality factors and which are more related to the state of disease. This research initiative aimed to extensively examine the distinct cognitive impairment profiles among the CHR, GHR, and first-episode schizophrenia (FES) cohorts. We compared the cognitive functions of the three groups and a healthy control group (HCs) using the MATRICS Consensus Cognitive Battery (MCCB). The participants for this study were recruited from the Beijing Anding Hospital of Capital Medical University. Our sample consisted of 56 patients with FES, 42 with CHR, 26 with GHR, and 62 HCs. The participants across all groups were matched in terms of gender, age, and level of education. Individuals with FES, GHR, and CHR showed significant impairment across the majority of MCCB domains, with the exception of visual learning, in comparison to HCs. None of the MCCB domains demonstrated a discerning ability to accurately differentiate between individuals with CHR and those with GHR. In the speed of processing and attention/vigilance domains, individuals with GHR and CHR exhibited scores between those of FES and HCs, with all group differences reaching statistical significance. This pattern of results indicates an intermediate level of cognitive function in individuals with GHR and CHR. Conversely, the levels of impairment observed in working memory and verbal learning were relatively consistent across all three groups: FES, CHR, and GHR. Notably, individuals in the CHR group exhibited performance akin to that of the HCs in the reasoning/problem-solving domain, while showing significant differences from the FES group, with the CHR individuals demonstrating better performance. Additionally, individuals with GHR displayed performance in social cognition similar to that of the HCs, while also demonstrating significant distinctions from the FES group, with the GHR individuals demonstrating better performance. Significant cognitive deficits exist in individuals with CHR, GHR, and FES, and these deficits vary across domains. Processing speed and attention/vigilance could potentially serve as robust biomarkers for identifying individuals at a risk of psychosis. The impairment observed in reasoning/problem-solving abilities might signify a qualitative trait, whereas deficits in social recognition could indicate a state characteristic specific to schizophrenia.

Generalizability and Out-of-Sample Predictive Ability of Associations Between Neuromelanin-Sensitive Magnetic Resonance Imaging and Psychosis in Antipsychotic-Free Individuals

The link between psychosis and dopaminergic dysfunction is established, but no generalizable biomarkers with clear potential for clinical adoption exist. To replicate previous findings relating neuromelanin-sensitive magnetic resonance imaging (NM-MRI), a proxy measure of dopamine function, to psychosis severity in antipsychotic-free individuals in the psychosis spectrum and to evaluate the out-of-sample predictive ability of NM-MRI for psychosis severity. This cross-sectional study recruited participants from 2019 to 2023 in the New York City area (main samples) and Mexico City area (external validation sample). The main samples consisted of 42 antipsychotic-free patients with schizophrenia, 53 antipsychotic-free individuals at clinical high risk for psychosis (CHR), and 52 matched healthy controls. An external validation sample consisted of 16 antipsychotic-naive patients with schizophrenia. NM-MRI contrast within a subregion of the substantia nigra previously linked to psychosis severity (a priori psychosis region of interest [ROI]) and psychosis severity measured using the Positive and Negative Syndrome Scale (PANSS) in schizophrenia and the Structured Interview for Psychosis-Risk Syndromes (SIPS) in CHR. The cross-validated performance of linear support vector regression to predict psychosis severity across schizophrenia and CHR was assessed, and a final trained model was tested on the external validation sample. Of the 163 included participants, 76 (46.6%) were female, and the mean (SD) age was 29.2 (10.4) years. In the schizophrenia sample, higher PANSS positive total scores correlated with higher mean NM-MRI contrast in the psychosis ROI (t37 = 2.24, P = .03; partial r = 0.35; 95% CI, 0.05 to 0.55). In the CHR sample, no significant association was found between higher SIPS positive total score and NM-MRI contrast in the psychosis ROI (t48 = -0.55, P = .68; partial r = -0.08; 95% CI, -0.36 to 0.23). The 10-fold cross-validated prediction accuracy of psychosis severity was above chance in held-out test data (mean r = 0.305, P = .01; mean root-mean-square error [RMSE] = 1.001, P = .005). External validation prediction accuracy was also above chance (r = 0.422, P = .046; RMSE = 0.882, P = .047). This study provided a direct ROI-based replication of the in-sample association between NM-MRI contrast and psychosis severity in antipsychotic-free patients with schizophrenia. In turn, it failed to replicate such association in CHR individuals. Most critically, cross-validated machine-learning analyses provided a proof-of-concept demonstration that NM-MRI patterns can be used to predict psychosis severity in new data, suggesting potential for developing clinically useful tools.

Linguistic correlates of suicidal ideation in youth at clinical high-risk for psychosis.

Suicidal ideation (SI) is prevalent among individuals at clinical high-risk for psychosis (CHR). Natural language processing (NLP) provides an efficient method to identify linguistic markers of suicidality. Prior work has demonstrated that an increased use of "I", as well as words with semantic similarity to "anger", "sadness", "stress" and "lonely", are correlated with SI in other cohorts. The current project analyzes data collected in an SI supplement to an NIH R01 study of thought disorder and social cognition in CHR. This study is the first to use NLP analyses of spoken language to identify linguistic correlates of recent suicidal ideation among CHR individuals. The sample included 43 CHR individuals, 10 with recent suicidal ideation and 33 without, as measured by the Columbia-Suicide Severity Rating Scale, as well as 14 healthy volunteers without SI. NLP methods include part-of-speech (POS) tagging, a GoEmotions-trained BERT Model, and Zero-Shot Learning. As hypothesized, individuals at CHR for psychosis who endorsed recent SI utilized more words with semantic similarity to "anger" compared to those who did not. Words with semantic similarity to "stress", "loneliness", and "sadness" were not significantly different between the two CHR groups. Contrary to our hypotheses, CHR individuals with recent SI did not use the word "I" more than those without recent SI. As anger is not characteristic of CHR, findings have implications for the consideration of subthreshold anger-related sentiment in suicidal risk assessment. As NLP is scalable, findings suggest that language markers may improve suicide screening and prediction in this population.

Meta-analysis of gender differences in transition prevalence among individuals at clinical high risk of psychosis.

Gender differences have been found in several areas of individuals at clinical-high risk for psychosis(CHR). Therefore the risk of transition to psychosis may differ between male and female CHR, but previous work has not systematically reviewed and analyzed gender differences in conversion rates.We performed a meta-analysis according to PRISMA guidelines including all studies that assessed CHR with reliable instruments and provided data on the transition from male CHR and female CHR to psychosis to understand the conversion rate conversion in male and female CHR. Seventy-nine article were identified.A total of 1250 out of 5770 in the male CHR individuals, and 832 out of 4468 in the female CHR individuals translated to psychotic disorders. Transition prevalence were 19.4%(95%CI:14.2-25.8%)at 1 year, 20.6% at 2 year (95%CI:17.1-24.8%),24.3% at 3 years (95%CI:21.5-27.4%),26.3% at 4 years or older (95%CI:20.9-32.5%) and 22.3% at all (95%CI:20.0-24.8%) in male CHR and 17.7% (95%CI:12.6-24.4%) at 1 years, 17.5% (95%CI:14.2-21.4%) at 2 year, 19.9%(95%CI:17.3-0.228%) at 3 years,and 0.267 (95%CI:22.1-31.9%) at 4 years or older follow-up,20.4% at all (95%CI:18.1-22.9%) in female CHR. There were differences between the two groups in the overall conversion, the 2-year, and the 3-year follow up transition prevalence, which were higher in men CHR than in female CHR. Future research characterizing male versus female CHR is needed with the expectation that interventions will be developed that are tailored to the respective gender, further reducing the rate of conversion to CHR.

Associations between age and neurocognition in individuals at clinical high risk and first-episode psychosis

Neurocognitive deficits differ with age during the early stages of psychosis. This study aimed to explore age-related differences (9–35 years old) in the neurocognitive performance of a large clinical population. In total, 1059 individuals with first-episode psychosis (FEP), 794 individuals with a clinical high risk of psychosis (CHR), and 774 well-matched healthy controls (HC) were recruited between 2016 and 2021. Neurocognitive assessments were performed using the Chinese version of the Measurement and Treatment Research to Improve Cognition in Schizophrenia Battery(MCCB). The MCCB subtest scores differed significantly among the groups across the age span. The mean scores of subtests in CHR individuals were approximately one standard deviation(SD) lower than that of HC, while that of FEP patients was approximately two SDs. The adolescents performed better than the adults in the HC, CHR, and FEP groups. In the HC group, a stronger correlation was found between age and cognitive function, and more neurocognitive domains were affected by age than in the CHR and FEP groups. These results emphasize that neurocognitive deficits in psychosis are present at the pre-onset stage and deteriorate at the first-episode stage across the age span, implicating the development of specific strategies that could monitor the cognitive trajectory in early psychosis.

The reliability and validity of the revised Green et al. paranoid thoughts scale in individuals at clinical high-risk for psychosis.

Paranoia is a common and impairing psychosis symptom, which exists along a severity continuum that extends into the general population. Individuals at clinical high-risk for psychosis (CHR) frequently experience paranoia and this may elevate their risk for developing full psychosis. Nonetheless, limited work has examined the efficient measurement of paranoia in CHR individuals. The present study aimed to validate an often-used self-report measure, the revised green paranoid thoughts scale (RGPTS), in this critical population. Participants were CHR individuals (n=103), mixed clinical controls (n=80), and healthy controls (n=71) who completed self-report and interview measures. Confirmatory factor analysis (CFA), psychometric indices, group differences, and relations to external measures were used to evaluate the reliability and validity of the RGPTS. CFA replicated a two-factor structure for the RGPTS and the associated reference and persecution scales were reliable. CHR individuals scored significantly higher on both reference and persecution, relative to both healthy (ds=1.03, 0.86) and clinical controls (ds=0.64, 0.73). In CHR participants, correlations between reference and persecution and external measures were smaller than expected, though showed evidence of discriminant validity (e.g., interviewer-rated paranoia, r=0.24). When examined in the full sample, correlation magnitude was larger and follow-up analyses indicated that reference related most specifically to paranoia (β=0.32), whereas persecution uniquely related to poor social functioning (β=-0.29). These results demonstrate the reliability and validity of the RGPTS, though its scales related more weakly to severity in CHR individuals. The RGPTS may be useful in future work aiming to develop symptom-specific models of emerging paranoia in CHR individuals.

The association between mental health stigma and face emotion recognition in individuals at risk for psychosis.

Self-stigma has been associated with reduced accuracy of face emotion recognition in individuals at clinical high risk for psychosis (CHR). Stigma may also relate to slowing of performance during cognitive tasks for which a negative stereotype is relevant. This study aimed to investigate the association of mental illness stigma with face emotion recognition among CHR individuals. Participants were 143 CHR individuals identified using the Structured Interview for Psychosis-Risk Syndromes (SIPS). Face emotion recognition was assessed using the Penn Emotion Recognition Task (ER-40). Stigma was assessed using discrimination, stereotype awareness, and stereotype agreement subscales of the Mental Health Attitudes Interview for CHR. We tested associations of ER-40 accuracy and response times with these stigma variables, including the role of clinical and demographic factors. Racial/ethnic minoritized participants had higher attenuated positive symptoms than non-minoritized participants. Longer ER-40 response times were correlated with greater stereotype agreement (r=.17, p=.045) and discrimination (r=.22, p=.012). A regression model predicting ER-40 response times revealed an interaction of stereotype agreement with minoritized status (p=.008), with slower response times for minoritized participants as stereotype agreement increased. Greater disorganized symptoms and male gender also predicted longer response times. ER-40 accuracy was not associated with stigma. Overall, minoritized CHR individuals with greater internalized stigma took longer to identify face emotions. Future research is needed to assess whether slower response times are specific to social cues, and if internalized stigma interferes with performance in real-world social situations. Reducing stigma may be an important target for interventions that aim to improve social skills.

Auditory N100 amplitude deficits predict conversion to psychosis in the North American Prodrome Longitudinal Study (NAPLS-2) cohort

BackgroundThe auditory N100 is an event related potential (ERP) that is reduced in schizophrenia, but its status in individuals at clinical high risk for psychosis (CHR) and its ability to predict conversion to psychosis remains unclear. We examined whether N100 amplitudes are reduced in CHR subjects relative to healthy controls (HC), and this reduction predicts conversion to psychosis in CHR. MethodsSubjects included CHR individuals (n = 552) and demographically similar HC subjects (n = 236) from the North American Prodrome Longitudinal Study. Follow-up assessments identified CHR individuals who converted to psychosis (CHRC; n = 73) and those who did not (CHR-NC; n = 225) over 24 months. Electroencephalography data were collected during an auditory oddball task containing Standard, Novel, and Target stimuli. N100 peak amplitudes following each stimulus were measured at electrodes Cz and Fz. ResultsThe CHR subjects had smaller N100 absolute amplitudes than HC subjects at Fz (F(1,786) = 4.00, p 0.046). A model comparing three groups (CHRC, CHR-NC, HC) was significant for Group at the Cz electrode (F(2,531) = 3.58, p = 0.029). Both Standard (p = 0.019) and Novel (p = 0.017) stimuli showed N100 absolute amplitude reductions in CHR-C relative to HC. A smaller N100 amplitude at Cz predicted conversion to psychosis in the CHR cohort (Standard: p = 0.009; Novel: p = 0.001) and predicted shorter time to conversion (Standard: p = 0.013; Novel: p = 0.001). ConclusionN100 amplitudes are reduced in CHR individuals which precedes the onset of psychosis. N100 deficits in CHR individuals predict a greater likelihood of conversion to psychosis. Our results highlight N100's utility as a biomarker of psychosis risk.

Sleep spindle alterations relate to working memory deficits in individuals at clinical high-risk for psychosis.

Sleep spindles are waxing and waning EEG waves exemplifying the main fast oscillatory activity occurring during NREM sleep. Several recent studies have established that sleep spindle abnormalities are present in schizophrenia spectrum disorders, including in early-course and first-episode patients, and those spindle deficits are associated with some of the cognitive impairments commonly observed in these patients. Cognitive deficits are often observed before the onset of psychosis and seem to predict poor functional outcomes in individuals at clinical high-risk for psychosis (CHR). Yet, the presence of spindle abnormalities and their relationship with cognitive dysfunction has not been investigated in CHR. In this study, overnight high-density (hd)-EEG recordings were collected in 24 CHR and 24 healthy control (HC) subjects. Spindle density, duration, amplitude, and frequency were computed and compared between CHR and HC. Furthermore, WM was assessed for both HC and CHR, and its relationship with spindle parameters was examined. CHR had reduced spindle duration in centro-parietal and prefrontal regions, with the largest decrease in the right prefrontal area. Moderation analysis showed that the relation between spindle duration and spindle frequency was altered in CHR relative to HC. Furthermore, CHR had reduced WM performance compared to HC, which was predicted by spindle frequency, whereas in HC spindle frequency, duration, and density all predicted working memory performance. Altogether, these findings indicate that sleep spindles are altered in CHR individuals, and spindle alterations are associated with their cognitive deficits, thus representing a sleep-specific putative neurophysiological biomarker of cognitive dysfunction in psychosis risk.

Three prominent self-report risk measures show unique and overlapping utility in characterizing those at clinical high-risk for psychosis

Self-report questionnaires have been developed to efficiently assess psychosis risk and vulnerability. Despite this, the validity of these questionnaires for assessing specific positive symptoms in those at clinical high risk for psychosis (CHR) is unclear. Positive symptoms have largely been treated as a uniform construct in this critical population and there have been no reports on the construct validity of questionnaires for assessing specific symptoms. The present study examined the convergent, discriminant, and criterion validity of the Launay Slade Hallucination Scale-Revised (LSHS-R), Prodromal Questionnaire-Brief (PQB), and Community Assessment of Psychic Experiences positive scale (CAPE-P) using a multimethod approach. CHR individuals (N = 71) and healthy controls (HC; N = 71) completed structured clinical interviews, self-report questionnaires, and neuropsychological tests. Questionnaire intercorrelations indicated strong convergent validity (i.e., all rs > .50); however, evidence for discriminant validity was more variable. In examining relations to interviewer-assessed psychosis symptoms, all questionnaires demonstrated evidence of criterion validity, though the PQB showed the strongest convergent correlations (e.g., r = .48 with total symptoms). In terms of discriminant validity for specific positive symptoms, results were again more variable. PQB subscales demonstrated limited specificity with positive symptoms, whereas CAPE-P subscales showed some specificity and the LSHS-R showed high specificity. In addition, when correlations with internalizing and externalizing symptoms were examined, only the PQB showed consistent significant correlations. These results are interpreted in terms of the strengths and limitations of each measure, their value for screening, and their potential utility for clarifying differences between specific positive symptoms.

Effect of cognitive insight on clinical insight from pre-morbid to early psychosis stages

Poor cognitive insight, including low self-reflectiveness and high self-certainty, contributes to poor clinical insight, which includes awareness of illness, relabelling of specific symptoms, and treatment compliance. However, inconsistent results regarding cognitive insight among individuals at clinical high risk of psychosis (CHR) have been reported. This study investigated the difference in cognitive insight among groups with different severity of positive symptoms and analysed the effect of cognitive insight on clinical insight in each group. All participants, including CHR individuals with 3 or 4 points (L-Pitem, n = 85) and 5 points (H-Pitem, n = 37) on any positive-symptom item of the Scale of Prodromal Syndromes, and patients with first-episode psychosis (FEP, n = 59), were measured cognitive and clinical insight using the Beck Cognitive Insight Scale and the Schedule of Assessment of Insight, respectively. The self-reflectiveness of cognitive insight was highest in the L-Pitem group and lowest in the FEP group. Self-reflectiveness was positively associated with awareness of illness in the L-Pitem and FEP groups; both self-reflectiveness and self-certainty was positively associated with treatment compliance in the L-Pitem group. Improving self-reflectiveness of cognitive insight may conduce to good clinical insight. Self-certainty may have different implication to individuals with mild prodromal symptoms.

P498. Intact Implicit Reinforcement Learning in Schizophrenia and Youth at Clinical High-Risk for Psychosis

Negative symptoms (e.g., amotivation) are prominent in schizophrenia (SZ). These symptoms begin early in the course of the disorder, including in youth at clinical high-risk for psychosis (CHR) with subthreshold psychotic symptoms. In SZ, negative symptoms are linked to reward-based learning dysfunction. However, previous research suggests implicit reinforcement learning remains intact in SZ. It is unknown whether CHR individuals also have preserved implicit reinforcement learning, knowledge of which may help clarify mechanistic pathways of negative symptoms and psychosis risk.

Reduced temporal activation during a verbal fluency test in clinical high risk of psychosis: a functional near-infrared spectroscopy-based study

BackgroundClinical high risk (CHR) of psychosis is a state in which positive symptoms cause the subjects distress but do not approach a severity level that fulfils the criteria for a...

Family history of psychosis in youth at clinical high risk: A replication study

Having a first-degree relative with a psychotic disorder increases an individual's risk for developing psychosis to 10% compared to 1% in the general population. The impact of being at family high-risk for psychosis (FHR) has been examined in samples of youth who are at clinical high-risk for psychosis (CHR). The second North American Prodrome Longitudinal Study (NAPLS-2) identified very few clinical differences between CHR individuals with and without FHR. This paper aims to confirm these results in a new CHR sample, NAPLS-3. The NAPLS-3 sample consisted of 703 CHR participants, of whom 82 were at FHR (CHR+FHR), and 621 were not (CHR+FHRneg). The Family Interview for Genetic Studies was used to determine the presence of a first-degree relative with a psychotic disorder. The groups were compared on social and role functioning, positive and negative symptoms, IQ, cannabis use, and trauma. At baseline, the CHR+FHR group reported a statistically significant increased severity of positive and negative symptoms, lower IQ scores, and increased reports of trauma, psychological and physical abuse. There were no differences in transition rates between the two groups. This study supports some of the already reported differences in trauma, physical and psychological abuse between CHR individuals with and without FHR.