Checking the predictive accuracy of basic symptoms against ultra high-risk criteria and testing of a multivariable prediction model: Evidence from a prospective three-year observational study of persons at clinical high-risk for psychosis

Clinical high risk for psychosis and service disengagement: Incidence and predictors across 2 years of follow-up

BACK: Service disengagement is common in subjects at CHR-P (clinical high risk for psychosis), potentially worsening daily functioning and increasing the duration of untreated psychosis. That is why to identify baseline predictors of service disengagement could help better tailoring follow-up on every CHR-P individual.

AIMS

Since there are few studies on this topic, the goals of this examination were: (1) to calculate service disengagement rates in a CHR-P sample along 2-years of follow-up; and (2) to examine the most relevant predictive factors of disengagement at baseline.

METHODS

All young CHR-P participants were enrolled within the 'Parma At-Risk Mental States' (PARMS) protocol. At entry, the Global Assessment of Functioning (GAF) scale and the positive and negative syndrome scale (PANSS) were completed. Cox regression analyses were used.

RESULTS

Hundred and eighty CHR-P subjects were recruited in this examination. During the follow-up, a 2-year service disengagement prevalence rate of 15% was observed. A statistically robust predictive factor of service disengagement was a lower prescription of antidepressant drug at entry. Other relevant baseline predictive factors were migrant status, higher GAF score, lower levels of anxious-depressive symptoms and a lower acceptance of psychosocial interventions.

DISCUSSION

Baseline presence of anxious-depressive features in CHR-P individuals could favour engagement to specialized EIP services. However, implementing strategies to improve patients' motivation and involvement in care are needed.

Engagement and Acceptability of Acceptance and Commitment Therapy in Daily Life in Early Psychosis: Secondary Findings From a Multicenter Randomized Controlled Trial

BACKGROUND

Acceptance and commitment therapy (ACT) is promising in the treatment of early psychosis. Augmenting face-to-face ACT with mobile health ecological momentary interventions may increase its treatment effects and empower clients to take treatment into their own hands.

OBJECTIVE

This study aimed to investigate and predict treatment engagement with and acceptability of acceptance and commitment therapy in daily life (ACT-DL), a novel ecological momentary intervention for people with an ultrahigh risk state and a first episode of psychosis.

METHODS

In the multicenter randomized controlled trial, 148 individuals with ultrahigh risk or first-episode psychosis aged 15-65 years were randomized to treatment as usual only (control) or to ACT-DL combined with treatment as usual (experimental), consisting of 8 face-to-face sessions augmented with an ACT-based smartphone app, delivering ACT skills and techniques in daily life. For individuals in the intervention arm, we collected data on treatment engagement with and acceptability of ACT-DL during and after the intervention. Predictors of treatment engagement and acceptability included baseline demographic, clinical, and functional outcomes.

RESULTS

Participants who received ACT-DL in addition to treatment as usual (n=71) completed a mean of 6 (SD 3) sessions, with 59% (n=42) of participants completing all sessions. App engagement data (n=58) shows that, on a weekly basis, participants used the app 13 times and were compliant with 6 of 24 (25%) notifications. Distribution plots of debriefing scores (n=46) show that 85%-96% of participants reported usefulness on all acceptability items to at least some extent (scores ≥2; 1=no usefulness) and that 91% (n=42) of participants reported perceived burden by number and length of notifications (scores ≥2; 1=no burden). Multiple linear regression models were fitted to predict treatment engagement and acceptability. Ethnic minority backgrounds predicted lower notification response compliance (B=-4.37; P=.01), yet higher app usefulness (B=1.25; P=.049). Negative (B=-0.26; P=.01) and affective (B=0.14; P=.04) symptom severity predicted lower and higher ACT training usefulness, respectively. Being female (B=-1.03; P=.005) predicted lower usefulness of the ACT metaphor images on the app.

CONCLUSIONS

Our results corroborate good treatment engagement with and acceptability of ACT-DL in early psychosis. We provide recommendations for future intervention optimization.

TRIAL REGISTRATION

OMON NL46439.068.13; https://onderzoekmetmensen.nl/en/trial/24803.

Combining Clinical With Cognitive or Magnetic Resonance Imaging Data for Predicting Transition to Psychosis in Ultra High-Risk Patients: Data From the PACE 400 Cohort

BACKGROUND

Multimodal modeling that combines biological and clinical data shows promise in predicting transition to psychosis in individuals who are at ultra-high risk. Individuals who transition to psychosis are known to have deficits at baseline in cognitive function and reductions in gray matter volume in multiple brain regions identified by magnetic resonance imaging.

METHODS

In this study, we used Cox proportional hazards regression models to assess the additive predictive value of each modality-cognition, cortical structure information, and the neuroanatomical measure of brain age gap-to a previously developed clinical model using functioning and duration of symptoms prior to service entry as predictors in the Personal Assessment and Crisis Evaluation (PACE) 400 cohort. The PACE 400 study is a well-characterized cohort of Australian youths who were identified as ultra-high risk of transitioning to psychosis using the Comprehensive Assessment of At Risk Mental States (CAARMS) and followed for up to 18 years; it contains clinical data (from N = 416 participants), cognitive data (n = 213), and magnetic resonance imaging cortical parameters extracted using FreeSurfer (n = 231).

RESULTS

The results showed that neuroimaging, brain age gap, and cognition added marginal predictive information to the previously developed clinical model (fraction of new information: neuroimaging 0%-12%, brain age gap 7%, cognition 0%-16%).

CONCLUSIONS

In summary, adding a second modality to a clinical risk model predicting the onset of a psychotic disorder in the PACE 400 cohort showed little improvement in the fit of the model for long-term prediction of transition to psychosis.

Effectiveness of a two-stage strategy using the 16-item Prodromal Questionnaire (PQ16/fPQ16) and the Comprehensive Assessment of At Risk Mental States (CAARMS) in the early detection of Ultra High Risk (UHR) patients in Lebanon: a cross-sectional pilot study

OBJECTIVES

This study aims to identify the prevalence of Ultra High Risk (UHR) adults in a sample of patients in Lebanon and to compare screening and diagnostic tools.

METHODS

This is a cross-sectional pilot study which targeted patients aged 17-30 years willingly seeking psychiatric care in a university hospital in Beirut, Lebanon. Participants were invited to fill either the English or the French version of the Prodromal Questionnaire (respectively, PQ16 or fPQ16). The abbreviated version of the "Comprehensive Assessment of At-Risk Mental States" (CAARMS) was then administered to all participants. The latter were subsequently sorted into one of the three UHR groups - vulnerability group, attenuated psychosis (APS), intermittent psychosis (BLIPS) - or were diagnosed as suffering from a psychotic disorder.

RESULTS

Thirty-one patients participated in this study. The prevalence of positive screening on the PQ16/fPQ16 and positive diagnosis of UHR on the CAARMS were respectively of 61.29% and 45%. The APS group was the most prevalent (71.42%). A positive psychosis screening on PQ16/fPQ16 was statistically related to a UHR diagnosis on CAARMS (p-value: 0.011 on Chi2 test), OR=8.5 (95% CI: 1.4-50.9; p-value: 0.018). No relation was found between PQ16/fPQ16 results and risk stratification or between the number of "True" responses on PQ16/fPQ16 and the intensity of symptoms on CAARMS. PQ16/fPQ16 statements 5, 9, 11 and 16 predicted a UHR diagnosis on CAARMS (p-value of 0.045, 0.006, 0.045 and 0.045, respectively).

CONCLUSION

This two-stage strategy for identifying UHR patients can be adopted in a tertiary health care center.

Mismatch negativity generation in subjects at risk for psychosis: source analysis is more sensitive than surface electrodes in risk prediction

Background

Deficits of mismatch negativity (MMN) in patients with schizophrenia have been demonstrated many times and there is growing evidence that alterations of MMN already exist in individuals at risk for psychosis. The present study examines differences in MMN between subjects fulfilling ultra-high risk (UHR) or only basic symptoms criteria and it addresses the question, if MMN source analysis can improve prediction of transition to psychosis.

Methods

The MMN to duration, frequency, and intensity deviants was recorded in 50 healthy controls and 161 individuals at risk for psychosis classified into three subgroups: only basic symptoms (n = 74), only ultra-high risk (n = 13) and persons who fulfill both risk criteria (n = 74). Based on a three-source model of MMN generation, we conducted an MMN source analysis and compared the amplitudes of surface electrodes and sources among the three groups.

Results

Significant differences in MMN generation among the four groups were revealed at surface electrodes Cz and C4 (p < 0.05) and at the frontal source (p < 0.001) for duration deviant stimuli. The 15 subjects from the risk groups who subsequently developed a manifest psychosis had a significantly lower MMN amplitude at frontal source (p = 0.019) without showing significant differences at surface electrodes. Low activity at frontal MMN source increased the risk of transition to manifest disease by the factor 3.12 in UHR subjects.

Conclusion

MMN activity differed significantly between subjects presenting only basic symptoms and subjects which additionally meet UHR criteria. The largest differences between groups as well as between individuals with and without transition were observed at the frontal source. The present results suggest that source analysis is more sensitive than surface electrodes in psychosis risk prediction by MMN.

White matter microstructure and the clinical risk for psychosis: A diffusion tensor imaging study of individuals with basic symptoms and at ultra-high risk

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This DTI cross-sectional study compared UHR, basic symptom & control groups (n = 112).

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The splenium of UHR individuals exhibited differences in fractional anisotropy (FA).

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Basic symptoms alone were not associated with white matter microstructure changes.

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Large differences in FA & radial diffusivity were found in converters to psychosis.

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Regional FA was inversely correlated with the general psychopathology domain.

Background

Widespread white matter abnormalities are a frequent finding in chronic schizophrenia patients. More inconsistent results have been provided by the sparser literature on at-risk states for psychosis, i.e., emerging subclinical symptoms. However, considering risk as a homogenous construct, an approach of earlier studies, may impede our understanding of neuro-progression into psychosis.

Methods

An analysis was conducted of 3-Tesla MRI diffusion and symptom data from 112 individuals (mean age, 21.97 ± 4.19) within two at-risk paradigm subtypes, only basic symptoms (n = 43) and ultra-high risk (n = 37), and controls (n = 32). Between-group comparisons (involving three study groups and further split based on the subsequent transition to schizophrenia) of four diffusion-tensor-imaging-derived scalars were performed using voxelwise tract-based spatial statistics, followed by correlational analyses with Structured Interview for Prodromal Syndromes responses.

Results

Relative to controls, fractional anisotropy was lower in the splenium of the corpus callosum of ultra-high-risk individuals, but only before stringent multiple-testing correction, and negatively correlated with General Symptom severity among at-risk individuals. At-risk participants who transitioned to schizophrenia within 3 years, compared to those that did not transition, had more severe WM differences in fractional anisotropy and radial diffusivity (particularly in the corpus callosum, anterior corona radiata, and motor/sensory tracts), which were even more extensive compared to healthy controls.

Conclusions

These findings align with the subclinical symptom presentation and more extensive disruptions in converters, suggestive of severity-related demyelination or axonal pathology. Fine-grained but detectable differences among ultra-high-risk subjects (i.e., with brief limited intermittent and/or attenuated psychotic symptoms) point to the splenium as a discrete site of emerging psychopathology, while basic symptoms alone were not associated with altered fractional anisotropy.

Attrition in longitudinal studies among patients with schizophrenia and other psychoses; findings from the STRATA collaboration

A major problem with longitudinal studies is the bias generated due to attrition, particularly apparent amongst patients suffering from psychotic disorders. Factors associated with study-participation were investigated as part of a larger research collaboration (STRATA). Out of 479 eligible participants, only 50 (10,4%) were successfully followed up. The present study investigated whether study participation differed depending on baseline characteristics. Results indicated that individuals who did not participate were more likely to report an alcohol use disorder while those who did respond were more likely to have been in full-time education for longer and be of white ethnicity. Participation did not differ depending on diagnosis, symptoms, GAF, age of onset or depression.

Prediction of clinical outcomes beyond psychosis in the ultra-high risk for psychosis population

AIM

Several prediction models have been introduced to identify young people at greatest risk of transitioning to psychosis. To date, none has examined the possibility of developing a clinical prediction model of outcomes other than transition. The aims of this study were to examine the association between baseline clinical predictors and outcomes including, but not limited to, transition to psychosis in young people at risk for psychosis, and to develop a prediction model for these outcomes.

METHODS

Several evidence-based variables previously associated with transition to psychosis and some important clinical comorbidities experienced by ultra-high risk (UHR) individuals were identified in 202 UHR individuals. Secondary analysis of the Neurapro clinical trial were conducted to investigate the associations between these variables and favourable (remission and recovery) or unfavourable (transition to psychosis, no remission, any recurrence and relapse) clinical outcomes. Logistic regression, best subset selection, Akaike Information Criterion and receiver operating characteristic curves were used to seek the best prediction model for clinical outcomes from all combinations of possible predictors.

RESULTS

When considered individually, only higher general psychopathology levels (P = .023) was associated with the unfavourable outcomes. Prediction models suggest that general psychopathology and functioning are predictive of unfavourable outcomes.

CONCLUSION

The predictive performance of the resulting models was modest and further research is needed. Nonetheless, when designing early intervention centres aiming to support individuals in the early phases of a mental disorder, the proper assessment of general psychopathology and functioning should be considered in order to inform interventions and length of care provided.

Towards clinical application of prediction models for transition to psychosis: A systematic review and external validation study in the PRONIA sample

A multitude of prediction models for a first psychotic episode in individuals at clinical high-risk (CHR) for psychosis have been proposed, but only rarely validated. We identified transition models based on clinical and neuropsychological data through a registered systematic literature search and evaluated their external validity in 173 CHRs from the Personalised Prognostic Tools for Early Psychosis Management (PRONIA) study. Discrimination performance was assessed with the area under the receiver operating characteristic curve (AUC), and compared to the prediction of clinical raters. External discrimination performance varied considerably across the 22 identified models (AUC 0.40-0.76), with two models showing good discrimination performance. None of the tested models significantly outperformed clinical raters (AUC = 0.75). Combining predictions of clinical raters and the best model descriptively improved discrimination performance (AUC = 0.84). Results show that personalized prediction of transition in CHR is potentially feasible on a global scale. For implementation in clinical practice, further rounds of external validation, impact studies, and development of an ethical framework is necessary.

Perceived Stress and Life Events in Patients Affected by Schizophrenia and Schizoaffective and Bipolar Disorder: Is There a Role for Self-Reported Basic Symptoms?

INTRODUCTION

The stress-diathesis model of psychotic disorders describes, in vulnerable individuals, the role of psychosocial stress in the onset and exacerbation of psychotic symptoms. Another interesting approach to the study of vulnerability in the development of psychosis is represented by the basic symptoms concept.

OBJECTIVE

The present study aims at proposing an integration between these two models and investigating possible associations between psychotic symptoms, basic symptoms, perceived stress, and life events in a sample of patients affected by schizophrenia (SZ), schizoaffective (SA), and bipolar disorder with and without psychotic symptoms.

METHODS

112 patients were recruited in two university hospitals. Severity of psychiatric symptoms (Positive and Negative Syndrome Scale, PANSS), basic symptoms (Frankfurt Complaint Questionnaire, FCQ), perceived stress (Stress-related Vulnerability Scale, SVS), and life events (Paykel's interview for recent life events) were assessed.

RESULTS

Patients affected by bipolar disorder (both with and without psychotic symptoms) showed a higher number of independent life events (p < 0.01) and tended to report more frequently at least 1 life event in the previous 6 months (p < 0.01) than patients affected by SZ or SA disorder. No differences emerged between the study groups in perceived stress nor in measures of basic symptoms. In the whole sample, a logistic regression analysis showed that the SVS total score (p < 0.05) and PANSS total score (p < 0.001) were associated with the presence of psychotic symptoms.

CONCLUSIONS

In the study sample, life events and basic symptoms did not play a major role in influencing psychotic symptoms, compared to the subjective perception of stress and the severity of psychopathology. Taken together, these results can be informative for rehabilitation therapies aimed at enhancing resilience and coping strategies in this vulnerable group of patients.

Predictors of study drop-out and service disengagement in patients at clinical high risk for psychosis

PURPOSE

Study drop-out during follow-up and service disengagement frequently occur in patients at clinical high risk for psychosis (CHR-P). However, little is known about their predictors. Therefore, we aimed to analyze the rate and reasons for drop-out and service disengagement in CHR-P patients and investigate their sociodemographic and clinical predictors.

METHODS

Data from 200 patients of the prospective Früherkennung von Psychosen (FePsy) study were analyzed with competing risks survival models, considering drop-out and transition to psychosis as competing events. To investigate whether symptoms changed immediately before drop-out, t tests were applied.

RESULTS

Thirty-six percent of patients dropped out within 5 years. Almost all drop-outs also disengaged from our service. Hence, study drop-out was used as a proxy for service disengagement. Patients with more severe baseline disorganized symptoms and a late inclusion into the study were significantly more likely to disengage. Immediately before disengagement, there was significant improvement in negative symptoms only.

CONCLUSION

A considerable proportion of CHR-P patients disengaged from our clinical study and service. Patients who were included during a later study period with more assessments disengaged more often, which might have been due to more frequent invitations to follow-up assessments and thereby increasing participation burden. Hence, our study provides a cautionary note on high-frequency follow-up assessments. Larger-scale studies evaluating predictors on multiple domains would help to further elucidate drop-out and disengagement.

Rare copy number variants in individuals at clinical high risk for psychosis: Enrichment of synaptic/brain-related functional pathways

Schizophrenia is a complex and chronic neuropsychiatric disorder, with a heritability of around 60-80%. Large (>100 kb) rare (<1%) copy number variants (CNVs) occur more frequently in schizophrenia patients compared to controls. Currently, there are no studies reporting genome-wide CNVs in clinical high risk for psychosis (CHR-P) individuals. The aim of this study was to investigate the role of rare genome-wide CNVs in 84 CHR-P individuals and 124 presumably healthy controls. There were no significant differences in all rare CNV frequencies and sizes between CHR-P individuals and controls. However, brain-related CNVs and brain-related deletions were significantly more frequent in CHR-P individuals than controls. In CHR-P individuals, significant associations were found between brain-related CNV carriers and attenuated positive symptoms syndrome or cognitive disturbances (OR = 3.07, p = .0286). Brain-related CNV carriers experienced significantly higher negative symptoms (p = .0047), higher depressive symptoms (p = .0175), and higher disturbances of self and surroundings (p = .0029) than noncarriers. Furthermore, enrichment analysis of genes was performed in the regions of rare CNVs using three independent methods, which confirmed significant clustering of predefined genes involved in synaptic/brain-related functional pathways in CHR-P individuals. These results suggest that rare CNVs might affect synaptic/brain-related functional pathways in CHR-P individuals.

Basic symptoms in young people at ultra-high risk of psychosis: Association with clinical characteristics and outcomes

There has been limited research into the predictive value of basic symptoms and their relationship with other psychopathology in patients identified using the 'ultra high risk' (UHR) for psychosis approach. The current study investigated whether basic symptoms, specifically cognitive disturbances (COGDIS), were associated with a greater risk of transition to psychotic disorder and persistent attenuated psychotic symptoms (APS) at medium term follow-up (mean = 3.4 years) in UHR patients, as well as with general psychopathology at baseline. The sample included 304 UHR participants (mean age = 19.12 years) involved in an international multicenter trial of omega-3 fatty acids. UHR individuals who also met the COGDIS criteria (basic symptoms risk criteria) did not have a greater risk of transition than those who met the UHR criteria alone. However, meeting COGDIS risk criteria was associated with a greater likelihood of meeting the UHR attenuated psychotic symptoms risk group (i.e., having persistent attenuated psychotic symptoms) at 12-month follow-up (odds ratio = 1.85; 95% CI = 1.03, 3.32). Greater severity of cognitive basic symptoms was also independently associated with more severe general psychopathology at study entry. The findings do not support the notion that combined risk identification approaches (UHR and basic symptoms) aid in the identification of individuals at greatest risk of psychosis, although this interpretation is limited by the modest transition to psychosis rate (13%) and the time of follow up. However, the findings indicate that basic symptoms may be a clinically useful marker of more severe general psychopathology in UHR groups and risk for persistent attenuated psychotic symptoms.

Exploring the predictive power of the unspecific risk category of the Basel Screening Instrument for Psychosis

AIM

Ultrahigh risk (UHR) criteria, consisting of brief limited intermittent psychotic symptoms (BLIPS), attenuated psychotic symptoms (APS) and genetic risk and deterioration (GRD) syndrome are the most widely used criteria for assessing the clinical high-risk state for psychosis (CHR-P). The Basel Screening Instrument for Psychosis (BSIP) includes a further risk category, the unspecific risk category (URC). However, little is known about the predictive power of this risk category compared to other risk categories.

METHODS

Two hundred CHR-P patients were detected as part of the Früherkennung von Psychosen (FePsy) study using the BSIP. Transition to psychosis was assessed in regular intervals for up to 7 years.

RESULTS

Patients meeting only the URC criterion (n = 40) had a significantly lower risk of transition to psychosis than the UHR group (including BLIPS, APS and GRD) (HR 0.19 [0.05; 0.80] (P = 0.024). Furthermore, the URC only risk group had a lower transition risk than the APS without BLIPS group (P = 0.015) and a trendwise lower risk than the BLIPS group (P = 0.066). However, despite the lower transition risk in the URC only group, there were still two patients (5%) in this group with a later transition to psychosis.

CONCLUSIONS

The URC includes patients who have a lower risk of transition than those included by the UHR categories and thereby increases the sensitivity of the BSIP. This offers the possibility of a stratified intervention, with these subjects receiving low intensity follow-up and treatment.

Borderline Personality Pathology in an At Risk Mental State Sample

Introduction: Transient psychotic symptoms in patients with borderline personality disorder seem to be similar to those in patients with psychotic disorders. Especially in the field of early detection of psychosis, this might lead to individuals with borderline personality disorder being wrongly classified as subjects at risk for developing a manifest psychosis. The aim of the present study was to investigate the occurrence of borderline symptoms in a sample of subjects at risk for psychosis as well as possible effects on the transition rate. Methods: Seventy help-seeking individuals of an early psychosis recognition center were additionally examined for borderline symptoms by the borderline symptom checklist. Results: We found a significant correlation between borderline symptomatology and positive symptoms assessed by the structured interview for prodromal symptoms. There were no associations between basic symptoms for psychosis and borderline symptoms. In addition, there was no influence of borderline symptomatology on the rate of transition into a manifest schizophrenic disease. Summary: In conclusion, borderline personality disorder should not be an exclusion criterion for the screening for psychosis or for an early intervention treatment. On the other hand, not every patient with borderline personality disorder, (especially those not suffering from hallucinations, unusual thought content, or persecutory ideas) should automatically be screened for the risk of developing a psychotic disorder.

At-risk studies and clinical antecedents of psychosis, bipolar disorder and depression: a scoping review in the context of clinical staging

Identifying young people at risk of developing serious mental illness and identifying predictors of onset of illness has been a focus of psychiatric prediction research, particularly in the field of psychosis. Work in this area has facilitated the adoption of the clinical staging model of early clinical phenotypes, ranging from at-risk mental states to chronic and severe mental illness. It has been a topic of debate if these staging models should be conceptualised as disorder-specific or transdiagnostic. In order to inform this debate and facilitate cross-diagnostic discourse, the present scoping review provides a broad overview of the body of literature of (a) longitudinal at-risk approaches and (b) identified antecedents of (homotypic) illness progression across three major mental disorders [psychosis, bipolar disorder (BD) and depression], and places these in the context of clinical staging. Stage 0 at-risk conceptualisations (i.e. familial high-risk approaches) were identified in all three disorders. However, formalised stage 1b conceptualisations (i.e. ultra-high-risk approaches) were only present in psychosis and marginally in BD. The presence of non-specific and overlapping antecedents in the three disorders may support a general staging model, at least in the early stages of severe psychotic or mood disorders.

Neurocognitive dysfunction in subjects at clinical high risk for psychosis: A meta-analysis

Findings of neurocognitive dysfunction in subjects at Clinical High Risk for Psychosis (CHR-P) have been controversial. This meta-analysis systematically examined studies of neurocognitive functions using the MATRICS Consensus Cognitive Battery (MCCB) in CHR-P. An independent literature search of both English and Chinese databases was conducted by two reviewers. Standardized mean difference (SMD) was calculated using a random effects model to evaluate the effect size of the meta-analytic results. Six case-control studies (n = 396) comparing neurocognitive functions between CHR-P subjects (n = 197) and healthy controls (n = 199) using the MCCB were identified; 4 (66.7%) studies were rated as "high quality". Compared to healthy controls, CHR-P subjects showed impairment with large effect size in overall cognition (n = 128, SMD = -1.00, 95%CI: -1.38, -0.63, P < 0.00001; I² = 2%), processing speed (SMD = -1.21) and attention/vigilance (SMD = -0.83), and with medium effect size in working memory (SMD = -0.76), reasoning and problem solving (SMD = -0.71), visual (SMD = -0.68) and verbal learning (SMD = -0.67). No significant difference between CHR-P subjects and controls was found regarding social cognition (SMD = -0.33, 95%CI: -0.76, 0.10, P = 0.14; I² = 70%) with small effect size. Apart from social cognition, CHR-P subjects performed worse than healthy control in all MCCB cognitive domains, particularly in processing speed, attention/vigilance and working memory.

Prediction Analysis for Transition to Schizophrenia in Individuals at Clinical High Risk for Psychosis: The Relationship of DAO, DAOA, and NRG1 Variants with Negative Symptoms and Cognitive Deficits

Schizophrenia is characterized by positive and negative symptoms and cognitive dysfunction. The glutamate hypothesis of schizophrenia has been hypothesized to explain the negative symptoms and cognitive deficits better than the dopamine hypothesis alone. Therefore, we aimed to evaluate whether glutamatergic variants such as d-amino acid oxidase (DAO), DAO activator (DAOA)/G72, and neuregulin 1 (NRG1) single-nucleotide polymorphisms (SNPs) and their mRNA levels predicted (i) transition to schizophrenia spectrum disorders and (ii) research domain criteria (RDoC) domains, mainly negative valence and cognitive systems. In a 3-year prospective study cohort of 185 individuals (age: 13-35 years) at high risk and ultra-high risk (UHR) for psychosis, we assessed DAO (rs3918347, rs4623951), DAOA (rs778293, rs3916971, rs746187), and NRG1 (rs10503929) SNPs and their mRNA expression. Furthermore, we investigated their association with RDoC domains, mainly negative valence (e.g., anxiety, hopelessness) and cognitive (e.g., perception disturbances, disorganized symptoms) systems. NRG1 rs10503929 CC + CT versus TT genotype carriers experienced significantly more disorganized symptoms. DAOA rs746187 CC versus CT + TT genotype, DAOA rs3916971 TT versus TC + CC genotype, and DAO rs3918347 GA + AA versus GG genotype carriers experienced nominally more hopelessness, visual perception disturbances, and auditory perception disturbances, respectively. The schizophrenia risk G-allele of DAO rs3918347 nominally increased risk for those UHR individuals with attenuated positive symptoms syndrome. No association between DAO, DAOA, NRG1 SNPs, and conversion to schizophrenia spectrum disorders was observed. Our findings suggest that DAO, DAOA, and NRG1 polymorphisms might influence both RDoC negative valence and cognitive systems, but not transition to schizophrenia spectrum disorders.