Attenuated niacin response is associated with a subtype of first-episode drug-naïve psychosis characterized as serious negative symptoms.

Although the phenomenon of attenuated niacin response (ANR) has been widely replicated in some patients with first-episode psychosis (FEP), its relevance to the negative symptoms (NS) of psychosis remains unclear. Total of 240 patients with drug-naïve FEP and 101 healthy controls (HCs) were recruited, and 209 were followed up for 1 year. Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS), and niacin-induced responses were measured using laser Doppler flowmetry. We calculated the log-transform EC50 [concentration of methyl nicotinate required to elicit a half-maximal blood flow (MBF) response] and MBF values. Core-NS was generated by factor analysis of the PANSS-NS subscale and cluster analysis to produce subtypes. Significant differences were found in the log10 (EC50) values between the FEP and HC groups (p < 0.001), supporting the ANR in patients with FEP. A higher NS severity was found in the ANR subgroup than that in other patients. Factor analysis determined that a two-dimensional model included core NS and rigidity of thinking. The log10 (EC50) value was significantly associated with only the core NS. Cluster analysis revealed three subtypes-36.7% (cluster-1, n = 88), 16.7% (cluster-2, n = 40), and 46.7% (cluster-3, n = 112). Cluster-2 characterized by extensive NS appeared to have a more remarkable ANR and less symptomatic improvement than those with other clusters during follow-up. No significant changes were found in the niacin response trajectories between the baseline and follow-up. Our findings indicate a significant correlation between ANR and core NS in patients with FEP. ANR may be a potential biomarker for certain subtypes with NS-dominated characteristics and poor symptomatic remission.

Automatic auditory processing features in distinct subtypes of patients at clinical high risk for psychosis: Forecasting remission with mismatch negativity.

Individuals at clinical high risk (CHR) for psychosis exhibit a compromised mismatch negativity (MMN) response, which indicates dysfunction of pre-attentive deviance processing. Event-related potential and time-frequency (TF) information, in combination with clinical and cognitive profiles, may provide insight into the pathophysiology and psychopathology of the CHR stage and predict the prognosis of CHR individuals. A total of 92 individuals with CHR were recruited and followed up regularly for up to 3 years. Individuals with CHR were classified into three clinical subtypes demonstrated previously, specifically 28 from Cluster 1 (characterized by extensive negative symptoms and cognitive deficits), 31 from Cluster 2 (characterized by thought and behavioral disorganization, with moderate cognitive impairment), and 33 from Cluster 3 (characterized by the mildest symptoms and cognitive deficits). Auditory MMN to frequency and duration deviants was assessed. The event-related spectral perturbation (ERSP) and inter-trial coherence (ITC) were acquired using TF analysis. Predictive indices for remission were identified using logistic regression analyses. As expected, reduced frequency MMN (fMMN) and duration MMN (dMMN) responses were noted in Cluster 1 relative to the other two clusters. In the TF analysis, Cluster 1 showed decreased theta and alpha ITC in response to deviant stimuli. The regression analyses revealed that dMMN latency and alpha ERSP to duration deviants, theta ITC to frequency deviants and alpha ERSP to frequency deviants, and fMMN latency were significant MMN predictors of remission for the three clusters. MMN variables outperformed behavioral variables in predicting remission of Clusters 1 and 2. Our findings indicate relatively disrupted automatic auditory processing in a certain CHR subtype and a close affinity between these electrophysiological indexes and clinical profiles within different clusters. Furthermore, MMN indexes may serve as predictors of subsequent remission from the CHR state. These findings suggest that the auditory MMN response is a potential neurophysiological marker for distinct clinical subtypes of CHR.

Temporal and time-frequency features of auditory oddball response in distinct subtypes of patients at clinical high risk for psychosis.

Individuals at clinical high risk (CHR) for psychosis exhibit a reduced P300 oddball response, which indicates deficits in attention and working memory processes. Previous studies have mainly researched these responses in the temporal domain; hence, non-phase-locked or induced neural activities may have been ignored. Event-related potential (ERP) and time-frequency (TF) information, combined with clinical and cognitive profiles, may provide an insight into the pathophysiology and psychopathology of the CHR stage. The 104 CHR individuals who completed cognitive assessments and ERP tests were recruited and followed up between 2016 and 2018. Individuals with CHR were classified by three clinical subtypes demonstrated before, specifically 32 from Cluster-1 (characterized by extensive negative symptoms and cognitive deficits, at the highest risk for conversion to psychosis), 34 from Cluster-2 (characterized by thought and behavioral disorganization, with moderate cognitive impairment), and 38 from Cluster-3 (characterized by the mildest symptoms and cognitive deficits). Electroencephalograms were recorded during the auditory oddball paradigm. The P300 ERPs were analyzed in the temporal domain. The event-related spectral perturbation (ERSP) and inter-trial coherence (ITC) were acquired by TF analysis. A reduced P300 response to target tones was noted in Cluster-1 relative to the other two clusters. Moreover, the P300 amplitude of Cluster-1 was associated with speed of processing (SoP) scores. Furthermore, the P300 amplitude of Cluster-3 was significantly correlated with verbal and visual learning scores. In the TF analysis, decreased delta ERSP and ITC were observed in Cluster-1; delta ITC was associated with SoP scores in Cluster-3. The results indicate relatively disrupted oddball responses in a certain CHR subtype and a close affinity between these electrophysiological indexes and attention, working memory, and declarative memory within different CHR clusters. These findings suggest that the auditory oddball response is a potential neurophysiological marker for distinct clinical subtypes of CHR.

Conversion to psychosis in adolescents and adults: similar proportions, different predictors.

BACKGROUND: Age effects may be important for improving models for the prediction of conversion to psychosis for individuals in the clinical high risk (CHR) state. This study aimed to explore whether adolescent CHR individuals (ages 9-17 years) differ significantly from adult CHR individuals (ages 18-45 years) in terms of conversion rates and predictors. METHOD: Consecutive CHR individuals (N = 517) were assessed for demographic and clinical characteristics and followed up for 3 years. Individuals with CHR were classified as adolescent (n = 244) or adult (n = 273) groups. Age-specific prediction models of psychosis were generated separately using Cox regression. RESULTS: Similar conversion rates were found between age groups; 52 out of 216 (24.1%) adolescent CHR individuals and 55 out of 219 (25.1%) CHR adults converted to psychosis. The conversion outcome was best predicted by negative symptoms compared to other clinical variables in CHR adolescents (χ2 = 7.410, p = 0.006). In contrast, positive symptoms better predicted conversion in CHR adults (χ2 = 6.585, p = 0.01). CONCLUSIONS: Adolescent and adult CHR individuals may require a different approach to early identification and prediction. These results can inform the development of more precise prediction models based on age-specific approaches.

Attenuated niacin-induced skin flush response in individuals with clinical high risk for psychosis.

Background: Impaired sensitivity of the skin flush response to niacin is one of the most replicated findings in patients with schizophrenia. However, prior studies have usually focused on postonset psychosis, and little is known about the clinical high-risk (CHR) phase of niacin sensitivity in psychosis. Aims: To profile and compare the niacin flush response among CHR individuals (converters and non-converters), patients with first-episode schizophrenia (FES) and healthy controls (HCs). Methods: Sensitivity to four concentrations (0.1-0.0001 M) of aqueous methylnicotinate was tested in 105 CHR individuals, 57 patients with FES and 52 HCs. CHR individuals were further grouped as converters and non-converters according to the 2-year follow-up outcomes. Skin flush response scores were rated on a 4-point scale. Results: Of the 105 CHR individuals, 21 individuals were lost during the study, leaving 84 CHR individuals; 16 (19.0%) converted to full psychosis at 2 years of follow-up. Flush response scores identified in the CHR samples were characterised as modest degree levels, intermediate between those of HC individuals and patients with FES. The flush responses in the CHR group mimicked the responses observed in the FES group at higher concentrations (0.01 M, 0.1 M) and longer time points (15 min, 20 min); however, these became comparable with the responses in the HC group at the shorter time points and at lower concentrations. The converters exhibited lower mean flush response scores than the non-converters. Conclusions: Attenuated niacin-induced flushing emerged during the early phase of psychosis. New devices should be developed and verified for objective quantification of skin responses in the CHR population.

Replication of the abnormal niacin response in first episode psychosis measured using laser Doppler flowmeter.

INTRODUCTION: Impaired sensitivity of the skin flush response to niacin is found in approximately 30% of patients with schizophrenia. Although the niacin response abnormality (NRA) may serve as a useful endophenotype for schizophrenia, few studies have directly replicated NRA in patients with first-episode psychosis (FEP). METHODS: In total, 204 patients with FEP, 16 with psychotic mood disorder (PMD), and 68 healthy controls (HC) were included. The log10 (EC50 ) values represent the concentration of methyl nicotinate required to elicit a half-maximal blood flow (MBF) response, and the MBF value was calculated. The NRA was defined as having log10 (EC50 ) molar value above the 90% and an MBF value below the 60% of those in the HC group. RESULTS: In total, 13.7% of the FEP, 12.5% of the PMD, and 7.4% of the HC group met the definition of NRA. Significant differences were found in the log10 (EC50 ) values between the FEP and HC groups (p = .014) and in the MBF between the FEP and PMD groups (p = .011). Patients with FEP and NRA had more severe negative symptoms than those with a normal niacin response. DISCUSSION: These data represent the NRA in patients with FEP, defining a small subgroup of patients with early-phase psychosis possessing a clinically significant phospholipid-signaling defect.

Antipsychotic prescription, assumption and conversion to psychosis: resolving missing clinical links to optimize prevention through precision.

The current concept of clinical high-risk(CHR) of psychosis relies heavily on "below-threshold" (i.e. attenuated or limited and intermittent) psychotic positive phenomena as predictors of the risk for future progression to "above-threshold" positive symptoms (aka "transition" or "conversion"). Positive symptoms, even at attenuated levels are often treated with antipsychotics (AP) to achieve clinical stabilization and mitigate the psychopathological severity. The goal of this study is to contextually examine clinicians' decision to prescribe AP, CHR individuals' decision to take AP and psychosis conversion risk in relation to prodromal symptoms profiles. CHR individuals (n = 600) were recruited and followed up for 2 years between 2016 and 2021. CHR individuals were referred to the participating the naturalistic follow-up study, which research procedure was independent of the routine clinical treatment. Clinical factors from the Structured Interview for Prodromal Syndromes (SIPS) and global assessment of function (GAF) were profiled via exploratory factor analysis (EFA), then the extracted factor structure was used to investigate the relationship of prodromal psychopathology with clinicians' decisions to AP-prescription, CHR individuals' decisions to AP-taking and conversion to psychosis. A total of 427(71.2%) CHR individuals were prescribed AP at baseline, 532(88.7%) completed the 2-year follow-up, 377(377/532, 70.9%) were taken AP at least for 2 weeks during the follow-up. EFA identified six factors (Factor-1-Negative symptoms, Factor-2-Global functions, Factor-3-Disorganized communication & behavior, Factor-4-General symptoms, Factor-5-Odd thoughts, and Factor-6-Distorted cognition & perception). Positive symptoms (Factor-5 and 6) and global functions (Factor-2) factors were significant predictors for clinicians' decisions to AP-prescription and CHR individuals' decisions to assume AP, whereas negative symptoms (Factor-1) and global functions (Factor-2) factors predicted conversion. While decisions to AP-prescription, decisions to AP-taking were associated to the same factors (positive symptoms and global functions), only one of those was predictive of conversion, i.e. global functions. The other predictor of conversion, i.e. negative symptoms, did not seem to be contemplated both on the clinician and patients' sides. Overall, the findings indicated that a realignment in the understanding of AP usage is warranted.

Antipsychotic Exposure in Clinical High Risk of Psychosis: Empirical Insights From a Large Cohort Study.

Objective: Current treatment guidelines for individuals at clinical high risk (CHR) for psychosis do not recommend the prescription of antipsychotics (not even second-generation ones) as the first treatment option for preventing psychosis. Yet, recent meta-analytic evidence indicates that antipsychotic exposure in CHR is relatively widespread and associated with a higher imminent risk of transition to psychosis. Therefore, we undertook this study to better delineate which clinical characteristics of CHR individuals may lead to the choice of antipsychotic prescription and whether it identifies a subgroup at higher risk for conversion to psychosis.Methods: Consecutively referred CHR individuals (N = 717) were assessed for demographic and clinical characteristics and followed up for 3 years (200 did not reach the end of the follow-up time) from 2016 to 2021. The sample was then dichotomized, on the basis of antipsychotic prescription, to prescribed (CHRAP+, n = 492) or not-prescribed (CHRAP-, n = 225) groups, which were subsequently compared for sociodemographic and clinical characteristics. The risks of conversion to psychosis in CHRAP+ versus CHRAP- groups were tested via survival analysis.Results: Of the 717 CHR individuals, 492 (68.62%) were prescribed antipsychotics; among these antipsychotics, the highest proportion used was for aripiprazole (n = 152), followed by olanzapine (n = 106), amisulpride (n = 76), and risperidone (n = 64). The CHRAP+ group had younger age (t = 2.138, P = .033), higher proportion of female individuals (χ2 = 5.084, P = .024), psychotic symptoms of greater severity (t = 7.910, P < .001), and more impaired general function (t = 5.846, P < .001) than the CHRAP- group. The CHRAP+ group had greater risk for conversion to psychosis (27.0% in the CHRAP+ group vs 10.9% in the CHRAP- group, P < .001). Factors related to positive symptoms were the most likely to influence doctors' decision-making regarding prescripton of antipsychotics, without influence of age, sex, and education levels.Conclusions: Clinicians may prescribe antipsychotics mainly based on the severity of positive and disorganization symptoms of CHR individuals. The CHRAP+ group was associated with a higher risk of conversion to psychosis. In pragmatic terms, this finding indicates that baseline antipsychotic prescription in CHR cohorts is a warning flag for higher incipient risk of psychosis and designates as hyper-CHR subgroup as compared to antipsychotic-naive CHR.Trial Registration: ClinicalTrials.gov identifier: NCT04010864.

A potential objective marker in first-episode schizophrenia based on abnormal niacin response.

The lack of objective diagnostic markers has long been a challenge in the clinical management of schizophrenia (SZ). The current bivariate cut-offs method is an objective quantification of niacin skin flush abnormality (NFA) for identifying the SZ subgroup. However, the sensitivity of approximately 30% limits the application of NFA as a marker for detecting SZ. A laser Doppler flowmeter was employed to test the niacin skin-flushing response in 123 patients with first-episode psychosis including first-episode SZ (FES, n = 82) and psychotic bipolar disorders (PBP, n = 41), and non-psychiatric comparisons (NPC, n = 80). We modified the bivariate cut-offs using a combination of the niacin concentration corresponding to the half-maximal blood flow response (EC50) and a new quantitative indicator called the overall trend area (OTA). The NFA used this study method predicted FES in the NPC group with 57% sensitivity, 89% specificity, and 73% accuracy compared to the 28% sensitivity, 91% specificity, and 59% accuracy of the existing method. This novel method could discern FES from the PBP group with an accuracy of 62%, compared with the 45% of the old method. In addition, we also discuss whether the bivariate cut-offs were occasional by adjusting the cut-offs threshold. The experimental results showed that the sensitivity and specificity were most stable when using the study method. The study indicates that NFA using modified bivariate cut-offs may be a potential objective marker in FES, and the niacin skin test could be feasible for early diagnosis and treatment of SZ.

Real-World Effectiveness and Safety of Antipsychotics in Individuals at Clinical High-Risk for Psychosis: Study Protocol for a Prospective Observational Study (ShangHai at Risk for Psychosis-Phase 2).

BACKGROUND: The clinical high-risk (CHR) state is identified as a critical period for early prevention and intervention during the development of psychosis and early treatment may reduce the risk of conversion to psychosis. However, it remains controversial whether antipsychotics are effective in CHR populations. Limited previous randomised controlled trials of antipsychotic treatment of CHR individuals indicated possible short-term efficacy on psychotic symptoms with unclear long-term effects. To answer this question, it is necessary to establish a high-quality real-world cohort study with large sample size to explore the effectiveness and safety of antipsychotics in CHR individuals. METHODS: We plan to consecutively recruit 600 CHR individuals from Shanghai Mental Health Centre in the ongoing SHARP-2 (ShangHai At Risk for Psychosis-Phase 2) project between 2019 and 2022. At baseline, participants will be assessed by the Structured Interview for Prodromal Syndromes, the MATRICS Consensus Cognitive Battery, demographic information, and clinical medication history. They will be followed up in a naturalistic way in which the research team will not prescribe antipsychotics or provide pharmacological consultation. First, CHR participants and their families will be trained to record their medication daily and self-evaluate symptoms through smart-phone application-based assessment and report their information weekly. Second, telephone calls will be arranged monthly so that the researchers are informed about the participants' symptoms, medications and daily functions. Third, face-to-face interviews will be conducted annually for repeating assessment of baseline. The primary outcomes will include conversion to psychosis and functional outcome (scored with less than 60 in the Global Assessment of Function) at the end of the follow-up period. CONCLUSION: The current study will improve our knowledge on the effectiveness and safety of the use of antipsychotics at the prodromal phase, and will eventually facilitate optimisation of individualised interventions for psychosis prevention and treatment.