Sustained specialized and family treatment in first-episode schizophrenia or related disorders: a 5-year randomized controlled trial.

BACKGROUND: The long-term outcome of first-episode schizophrenia needs improvement. Here, we evaluate the effectiveness of 5 years sustained specialist treatment (ST), ST including Parent groups (ST + P) or treatment as usual (TAU) on psychotic relapse and social functioning. METHODS: A three condition randomized, parallel assigned, single-blind efficacy trial, in which 198 first-episode psychosis (FEP) patients aged 15-28 years were included. The effect on time to first relapse, first relapse rates, mean number of relapses per patient, and time to the improvement of social functioning were analyzed using Cox regression or ANOVA. RESULTS: We found no significant differences between treatment conditions in the ITT analysis concerning time to first relapse, nor first relapse rate. Mean number of relapses per patient differed at a trend level between ST, ST + P or TAU conditions, respectively: 0.72; 0.62 or 1.02 (p = 0.069). No evidence was found for differential effect of treatment conditions on social functioning. CONCLUSION: Five years sustained ST of FEP nor addition of parent groups increased time to first relapse or reduced first relapse rate, compared to sustained TAU. Indications for favorable effects of parent groups were found on relapses per patient.

Childhood adversity predicts persistence of suicidal thoughts differently in females and males at clinical high-risk patients of psychosis. Results of the EPOS project.

AIM: Depression and suicidal ideation (SUI) and behaviour are more prevalent in females than males, and common in clinical high-risk (CHR) patients. Childhood adversities and trauma (CAT) are associated with adult depression and SUI. The role of gender as a moderator and depression as a mediator for the effect of CAT on SUI has not been explored in CHR patients. METHODS: In all, 245 young help-seeking CHR patients were assessed for SUI (thoughts of killing themselves) with the Beck Depression Inventory at baseline, 9-month and 18-month follow-ups. At baseline, clinical depression was assessed by the Structured Clinical Interview for DSM-IV (SCID-I), and CAT by the Trauma and Distress Scale (TADS) which includes the five domains of emotional, physical and sexual abuse, emotional and physical neglect. RESULTS: CAT total and all domains except physical neglect predicted SUI over the study period. The effect of CAT on SUI was mediated via clinical depression and concurrent depression symptoms differently for females and males. In females, the effect of emotional abuse and neglect on SUI was mediated via baseline depression. In males, emotional and physical abuse had a direct effect on SUI, and the effect of sexual abuse and emotional neglect was partly mediated via concurrent depression symptoms. CONCLUSIONS: For CHR females, the effect of CAT on adult SUI is mediated via depression, while for males, CAT and its domains have mainly direct effects in maintaining SUI. These gender differences should be taken into account when treating CHR patients with SUI.

Expressed emotion as a predictor of the first psychotic episode - Results of the European prediction of psychosis study.

OBJECTIVE: To investigate the impact of expressed emotion (EE) on the risk of developing the first psychotic episode (FEP). METHOD: The European Prediction of Psychosis Study (EPOS) investigated 245 patients who were at clinical high risk (CHR) of psychosis. The predictive value of EE alone and as a part of the multivariate EPOS model was evaluated. RESULTS: "Perceived irritability", a domain of the Level of Expressed Emotion Scale (LEE), was found to be predictive for the First Psychotic Episode (FEP), even as an individual variable. Furthermore, it was selected in the multivariate EPOS prediction model, thereby replacing two of the original predictor variables. This led to an improved revised version that enabled the identification of three significantly different risk classes with a hazard rate of up to 0.911. CONCLUSIONS: CHR subjects who perceive the most important person in their individual social environment to be limited in their stress coping skills had a higher risk of conversion to the first psychotic episode. The importance of this risk factor was further demonstrated by an improvement of risk estimation in the original EPOS predictor model. Perceiving a reference person as stress-prone and thus potentially unreliable might amplify self-experienced uncertainty and anxiety, which are often associated with the prodromal phase. Such an enforcement of stress-related processes could promote a conversion to psychosis.

Four-Year Cost-effectiveness of Cognitive Behavior Therapy for Preventing First-episode Psychosis: The Dutch Early Detection Intervention Evaluation (EDIE-NL) Trial.

Background: This study aims to evaluate the long-term cost-effectiveness of add-on cognitive behavior therapy (CBT) for the prevention of psychosis for individuals at ultrahigh risk (UHR) of psychosis. Method: The Dutch Early Detection and Intervention randomized controlled trial was used, comparing routine care (RC; n = 101) with routine care plus CBT for UHR (here called CBTuhr; n = 95). A cost-effectiveness analysis was conducted with treatment response (defined as proportion of averted transitions to psychosis) as an outcome and a cost-utility analysis with quality-adjusted life years (QALYs) gained as a secondary outcome. Results: The proportion of averted transitions to psychosis was significantly higher in the CBTuhr condition (with a risk difference of 0.122; b = 1.324, SEb = 0.017, z = 7.99, P < 0.001). CBTuhr showed an 83% probability of being more effective and less costly than RC by -US$ 5777 (savings) per participant. In addition, over the 4-year follow-up period, cumulative QALY health gains were marginally (but not significantly) higher in CBTuhr than for RC (2.63 vs. 2.46) and the CBTuhr intervention had a 75% probability of being the superior treatment (more QALY gains at lower costs) and a 92% probability of being cost-effective compared with RC at the Dutch threshold value (US$ 24 560; €20 000 per QALY). Conclusions: Add-on preventive CBTuhr had a high likelihood (83%) of resulting in more averted transitions to psychosis and lower costs as compared with RC. In addition, the intervention had a high likelihood (75%) of resulting in more QALY gains and lower costs as compared to RC.

The Prodromal Questionnaire: a case for IRT-based adaptive testing of psychotic experiences?

Computerized adaptive tests (CATs) for positive and negative psychotic experiences were developed and tested in N = 5705 help-seeking, non-psychotic young individuals. Instead of presenting all items, CATs choose a varying number of different items during test administration depending on respondents' previous answers, reducing the average number of items while still obtaining accurate person estimates. We assessed the appropriateness of two-parameter logistic models to positive and negative symptoms of the Prodromal Questionnaire (PQ), computed measurement precision of all items and resulting adaptive tests along psychotic dimensions by Real Data Simulations (RDS), and computed indices for criterion and predictive validities of the CATs. For all items, mean absolute differences between observed and expected response probabilities were smaller than 0.02. CAT-POS predicted transition to psychosis and duration of hospitalization in individuals at-risk for psychosis, and CAT-NEG was suggestively related to later functioning. Regarding psychosis risk classifications of help-seeking individuals, CAT-POS performed less than the PQ-16. Adaptive testing based on self-reported positive and negative symptoms in individuals at-risk for psychosis is a feasible method to select patients for further risk classification. These promising findings need to be replicated prospectively in a non-selective sample that also includes non-at-risk individuals. Copyright © 2016 John Wiley & Sons, Ltd.

The effect of childhood adversity on 4-year outcome in individuals at ultra high risk for psychosis in the Dutch Early Detection Intervention Evaluation (EDIE-NL) Trial.

Childhood adversity is associated with a range of mental disorders, functional impairment and higher health care costs in adulthood. In this study we evaluated if childhood adversity was predictive of adverse clinical and functional outcomes and health care costs in a sample of patients at ultra-high risk (UHR) for developing a psychosis. Structural Equation Modeling was used to examine the effect of childhood adversity on depression, anxiety, transition to psychosis and overall functioning at 4-year follow-up. In addition, we evaluated economic costs of childhood adversity in terms of health care use and productivity loss. Data pertain to 105 UHR participants of the Dutch Early Detection and Intervention Evaluation (EDIE-NL). Physical abuse was associated with higher depression rates (b=0.381, p=0.012) and lower social functional outcome (b=-0.219, p=0.017) at 4-year follow-up. In addition, emotional neglect was negatively associated with social functioning (b=-0.313, p=0.018). We did not find evidence that childhood adversity was associated with transition to psychosis, but the experience of childhood adversity was associated with excess health care costs at follow-up. The data indicate long-term negative effects of childhood adversity on depression, social functioning and health care costs at follow-up in a sample of UHR patients.

COMT Val(158)Met genotype and cannabis use in people with an At Risk Mental State for psychosis: Exploring Gene x Environment interactions.

BACKGROUND: Epidemiological and retrospective studies suggest a cannabis x catechol-O-methyltransferase (COMT) Val(158)Met interaction effect on development of psychosis. The aim of this study was to examine this interaction and its association with severity of subclinical symptoms in people with an At Risk Mental State (ARMS) for psychosis. METHODS: Severity of symptoms, cannabis use and genotype were assessed at baseline in 147 help-seeking young adults who met the ARMS criteria and agreed to participate in the Dutch Early Detection and Intervention (EDIE-NL) trial. RESULTS: Cannabis use and COMT Val-allele showed an interaction effect in ARMS subjects. Subjects who were weekly cannabis users at some point prior to entering the study showed more severe positive symptoms. This effect increased if they were carriers of the COMT Val-allele and even more so if they were homozygous for the Val-allele. CONCLUSIONS: Our results suggest that the COMT Val(158)Met polymorphism moderates the effect of regular cannabis use on severity of subclinical psychotic symptoms.

Four-Year Follow-up of Cognitive Behavioral Therapy in Persons at Ultra-High Risk for Developing Psychosis: The Dutch Early Detection Intervention Evaluation (EDIE-NL) Trial.

BACKGROUND: Previously, we demonstrated that cognitive behavior therapy for ultra-high risk (called CBTuhr) halved the incidence of psychosis over an 18-month period. Follow-up data from the same study are used to evaluate the longer-term effects at 4 years post-baseline. METHOD: The Dutch Early Detection and Intervention Evaluation study was a randomized controlled trial of 196 UHR patients comparing CBTuhr with treatment-as-usual (TAU) for comorbid disorders with TAU only. Of the original 196 patients, 113 consented to a 4-year follow-up (57.7%; CBTuhr = 56 vs TAU = 57). Over the study period, psychosis incidence, remission from UHR status, and the effects of transition to psychosis were evaluated. RESULTS: The number of participants in the CBTuhr group making the transition to psychosis increased from 10 at 18-month follow-up to 12 at 4-year follow-up whereas it did not change in the TAU group (n = 22); this still represents a clinically important (incidence rate ratio [IRR] = 12/22 = 0.55) and significant effect (F(1,5) = 8.09, P = .03), favoring CBTuhr. The odds ratio of CBTuhr compared to TAU was 0.44 (95% CI: 0.24-0.82) and the number needed to treat was 8. Moreover, significantly more patients remitted from their UHR status in the CBTuhr group (76.3%) compared with the TAU group (58.7%) [t(120) = 2.08, P = .04]. Importantly, transition to psychosis was associated with more severe psychopathology and social functioning at 4-year follow-up. CONCLUSIONS: CBTuhr to prevent a first episode of psychosis in persons at UHR of developing psychosis is still effective at 4-year follow-up. Our data also show that individuals meeting the formal criteria of a psychotic disorder have worse functional and social outcomes compared with non-transitioned cases. TRIAL REGISTRATION: The trial is registered at Current Controlled Trials as trial number ISRCTN21353122 (http://controlled-trials.com/ISRCTN21353122/gaag).

Depression predicts persistence of paranoia in clinical high-risk patients to psychosis: results of the EPOS project.

BACKGROUND: The link between depression and paranoia has long been discussed in psychiatric literature. Because the causality of this association is difficult to study in patients with full-blown psychosis, we aimed to investigate how clinical depression relates to the presence and occurrence of paranoid symptoms in clinical high-risk (CHR) patients. METHODS: In all, 245 young help-seeking CHR patients were assessed for suspiciousness and paranoid symptoms with the structured interview for prodromal syndromes at baseline, 9- and 18-month follow-up. At baseline, clinical diagnoses were assessed by the Structured Clinical Interview for DSM-IV, childhood adversities by the Trauma and Distress Scale, trait-like suspiciousness by the Schizotypal Personality Questionnaire, and anxiety and depressiveness by the Positive and Negative Syndrome Scale. RESULTS: At baseline, 54.3% of CHR patients reported at least moderate paranoid symptoms. At 9- and 18-month follow-ups, the corresponding figures were 28.3 and 24.4%. Depressive, obsessive-compulsive and somatoform disorders, emotional and sexual abuse, and anxiety and suspiciousness associated with paranoid symptoms. In multivariate modelling, depressive and obsessive-compulsive disorders, sexual abuse, and anxiety predicted persistence of paranoid symptoms. CONCLUSION: Depressive disorder was one of the major clinical factors predicting persistence of paranoid symptoms in CHR patients. In addition, obsessive-compulsive disorder, childhood sexual abuse, and anxiety associated with paranoia. Effective pharmacological and psychotherapeutic treatment of these disorders and anxiety may reduce paranoid symptoms in CHR patients.

Emotion processing in schizophrenia is state and trait dependent.

BACKGROUND: Substantial evidence exists about emotion processing (EP) impairments in schizophrenia patients. However, whether these deficits are present primarily during psychosis (i.e., state dependent) or an integral part of the disorder (i.e., trait dependent) remains unclear. METHODS: EP was assessed with the degraded facial affect recognition task in schizophrenia patients (N=521) and healthy controls (N=312) at baseline (T1) and after a three year follow-up (T2). In schizophrenia patients symptomatic remission was assessed with the Positive and Negative Syndrome Scale (PANSS) remission tool. Patients were divided into four groups: remission T1 and remission T2 (RR); remission T1 and non-remission T2 (RN); non-remission T1 and non-remission T2 (NN) and non-remission T1 and remission T2 (NR). Factorial repeated measures ANCOVA was used to compare EP performance over time between groups. Age, gender and general cognition were included as covariates. RESULTS: Schizophrenia patients performed worse than healthy controls on EP at T1 (p=0.001). The patients that were in symptomatic remission at both time points (the RR group) performed worse than the healthy controls at T2 (p<0.001). Significant group×time interactions were found between RR and RN (p=0.001), and between NR and RN (p=0.04), indicating a differential EP performance over time. No group×time interaction was found between NN and NR. CONCLUSION: The results show relatively poor EP performance in schizophrenia patients compared to healthy controls. EP performance in schizophrenia patients was associated with symptomatic remission. The results provide support for the hypothesis that EP deficits in schizophrenia are both state and trait dependent.

Qualitative and quantitative aspects of information processing in first psychosis: latent class analyses in patients, at-risk subjects, and controls.

We aimed to determine profiles of information processing deficits in the pathway to first psychosis. Sixty-one subjects at ultrahigh risk (UHR) for psychosis were assessed, of whom 18 converted to a first episode of psychosis (FEP) within the follow-up period. Additionally, 47 FEP and 30 control subjects were included. Using 10 neurophysiological parameters associated with information processing, latent class analyses yielded three classes at baseline. Class membership was related to group status. Within the UHR sample, two classes were found. Transition to psychosis was nominally associated with class membership. Neurophysiological profiles were unstable over time, but associations between specific neurophysiological components at baseline and follow-up were found. We conclude that certain constellations of neurophysiological variables aid in the differentiation between controls and patients in the prodrome and after first psychosis.

Selecting an optimal instrument to identify active ingredients of the motivational interviewing-process.

OBJECTIVE: Motivational Interviewing (MI) can effectively stimulate motivation for health behavior change, but the active ingredients of MI are not well known. To help clinicians further stimulate motivation, they need to know the active ingredients of MI. A psychometrically sound instrument is required to identify those ingredients. The purpose of this study is to describe and evaluate the capability of existing instruments to reliably measure one or more potential active ingredients in the MI process between clients and MI-therapists. METHODS: We systematically searched MedLine, Embase, Cinahl, PsycInfo, Cochrane Central, specialised websites and reference lists of selected articles. RESULTS: We found 406 papers, 60 papers were retrieved for further evaluation, based on prespecified criteria. Seventeen instruments that were specifically designed to measure MI or aspects of MI were identified. Fifteen papers met all inclusion criteria, and reported on seven instruments that assess potential active ingredients of the interactive MI process. The capability of these instruments to measure potential active ingredients in detail and as a part of the interactive MI process varies considerably. Three of these instruments measure one or more potential active ingredients in a reliable and valid way. CONCLUSION: To identify the potential active ingredients in the interactive MI process, a combination of the SCOPE (which measures potential technical active ingredients) and the GROMIT or the global ratings of the MISC2 (to measure potential relational ingredients) seems favourable.

Sensory gating in subjects at ultra high risk for developing a psychosis before and after a first psychotic episode.

OBJECTIVES: To explore sensory gating deficits in subjects at Ultra High Risk (UHR) for psychosis before and after transition to a first psychotic episode. METHODS: Sensory gating was assessed with the paired click paradigm in 61 UHR subjects, of whom 18 (30%) made a transition to psychosis (UHR + T) over a 3-year follow-up period and 28 matched healthy controls. Subjects were assessed at inclusion and again after approximately 18 months. P50, N100 (N1) and P200 (P2) sensory gating was established using the amplitude on the first (S1) and second (S2) click, the ratio- (S2/S1) and the difference score (S1-S2). Psychopathology was also assessed. RESULTS: At baseline, UHR + T subjects presented smaller N1 difference scores compared to UHR + NT subjects and controls. The N1 difference score contributed modestly to the prediction of a first psychotic episode. Repeated measure analyses revealed smaller N1 and P2 S1 amplitudes, smaller P2 difference scores and larger P2 ratio's at follow-up compared to baseline in UHR + T subjects. CONCLUSION: The N1 difference score may be helpful in predicting a first psychosis. N1 and P2 sensory gating measures also showed alterations between the prodromal phase and the first psychosis, suggesting that these changes may relate to the onset of a frank psychotic episode.

Can quantitative EEG measures predict clinical outcome in subjects at Clinical High Risk for psychosis? A prospective multicenter study.

BACKGROUND: Prediction studies in subjects at Clinical High Risk (CHR) for psychosis are hampered by a high proportion of uncertain outcomes. We therefore investigated whether quantitative EEG (QEEG) parameters can contribute to an improved identification of CHR subjects with a later conversion to psychosis. METHODS: This investigation was a project within the European Prediction of Psychosis Study (EPOS), a prospective multicenter, naturalistic field study with an 18-month follow-up period. QEEG spectral power and alpha peak frequencies (APF) were determined in 113 CHR subjects. The primary outcome measure was conversion to psychosis. RESULTS: Cox regression yielded a model including frontal theta (HR=1.82; [95% CI 1.00-3.32]) and delta (HR=2.60; [95% CI 1.30-5.20]) power, and occipital-parietal APF (HR=.52; [95% CI .35-.80]) as predictors of conversion to psychosis. The resulting equation enabled the development of a prognostic index with three risk classes (hazard rate 0.057 to 0.81). CONCLUSIONS: Power in theta and delta ranges and APF contribute to the short-term prediction of psychosis and enable a further stratification of risk in CHR samples. Combined with (other) clinical ratings, EEG parameters may therefore be a useful tool for individualized risk estimation and, consequently, targeted prevention.

Pre-pulse inhibition and striatal dopamine in subjects at an ultra-high risk for psychosis.

Reduced prepulse inhibition (PPI) of the acoustic startle response is thought to represent a robust biomarker in schizophrenia. Reduced PPI has been demonstrated in subjects at ultra high risk (UHR) for developing psychosis. Imaging studies report disruption of striatal dopaminergic neurotransmission in patients with schizophrenia. First, we compared the PPI of the acoustic startle response in UHR subjects versus healthy controls, to see if we could replicate previous findings of reduced PPI; secondly, we investigated our hypothesis that PPI would be negatively correlated with striatal synaptic dopamine (DA) concentration. We measured the startle reactivity and PPI of the acoustic startle response in 14 UHR subjects, and 14 age- and gender-matched healthy controls. Imaging of 11 UHR subjects and 11 healthy controls was completed by an [(123)I]-IBZM (radiotracer for dopamine D2/3 receptors) SPECT, at baseline and again after DA depletion with alpha-methyl-para-tyrosine (AMPT). The percentage change in striatal [(123)I]-IBZM radiotracer binding potential is a proxy of striatal synaptic DA concentration. UHR subjects showed reduced PPI, compared to control subjects. In both UHR and control subjects, there were no significant correlations between striatal synaptic DA concentration and PPI. We provide further evidence for the hypothesis that these two biomarkers are measuring different aspects of pathophysiology.

Pathways to care in subjects at high risk for psychotic disorders - a European perspective.

Evidence-based decisions on indicated prevention in early psychosis require large-scale studies on the pathways to care in high-risk subjects. EPOS (The European Prediction of Psychosis Study), a prospective multi-center, naturalistic field study in four European countries (Finland, Germany, The Netherlands and England), was designed to acquire accurate knowledge about pathways to care and delay in obtaining specialized high risk care. Our high risk sample (n=233) reported on average 2.9 help-seeking contacts, with an average delay between onset of relevant problems to initial help-seeking contact of 72.6 weeks, and between initial help-seeking contact and reaching specialized high risk care of 110.9 weeks. This resulted in a total estimated duration of an unrecognized risk for psychosis of 3 ½ years. Across EPOS EU regions, about 90% of care pathway contacts were within professional health care sectors. Between EPOS regions, differences in the pathways parameters including early detection and health-care systems were often very pronounced. High-risk participants who later made transition to a full psychotic disorder had significantly longer delays between initial help-seeking and receiving appropriate interventions. Our study underlines the need for regionally adapted implementation of early detection and intervention programs within respective mental health and health care networks, including enhancing public awareness of early psychosis.

A genome-wide association analysis of a broad psychosis phenotype identifies three loci for further investigation.

BACKGROUND: Genome-wide association studies (GWAS) have identified several loci associated with schizophrenia and/or bipolar disorder. We performed a GWAS of psychosis as a broad syndrome rather than within specific diagnostic categories. METHODS: 1239 cases with schizophrenia, schizoaffective disorder, or psychotic bipolar disorder; 857 of their unaffected relatives, and 2739 healthy controls were genotyped with the Affymetrix 6.0 single nucleotide polymorphism (SNP) array. Analyses of 695,193 SNPs were conducted using UNPHASED, which combines information across families and unrelated individuals. We attempted to replicate signals found in 23 genomic regions using existing data on nonoverlapping samples from the Psychiatric GWAS Consortium and Schizophrenia-GENE-plus cohorts (10,352 schizophrenia patients and 24,474 controls). RESULTS: No individual SNP showed compelling evidence for association with psychosis in our data. However, we observed a trend for association with same risk alleles at loci previously associated with schizophrenia (one-sided p = .003). A polygenic score analysis found that the Psychiatric GWAS Consortium's panel of SNPs associated with schizophrenia significantly predicted disease status in our sample (p = 5 × 10(-14)) and explained approximately 2% of the phenotypic variance. CONCLUSIONS: Although narrowly defined phenotypes have their advantages, we believe new loci may also be discovered through meta-analysis across broad phenotypes. The novel statistical methodology we introduced to model effect size heterogeneity between studies should help future GWAS that combine association evidence from related phenotypes. Applying these approaches, we highlight three loci that warrant further investigation. We found that SNPs conveying risk for schizophrenia are also predictive of disease status in our data.

Feasibility of teaching motivational interviewing to parents of young adults with recent-onset schizophrenia and co-occurring cannabis use.

This study examined the feasibility of providing motivational interviewing (MI) training to parents of young adults with recent-onset schizophrenia and co-occurring cannabis use. The training was offered in a mental health care setting as part of a family motivational intervention (FMI). Ninety-seven parents were randomly assigned to either FMI or routine family support (RFS). To obtain a measure of parent's MI skills at baseline and 3 months after they completed FMI, their role-play interactions with an actor portraying their child were coded. The coding method had satisfactory inter-rater reliability and internal consistency. At follow-up, parents in FMI showed significantly greater adherence to (p=.03) and competence in (p=.04) MI than parents in RFS. Parents in FMI also demonstrated significantly greater increases in expressing empathy (p=.01). These results demonstrate that FMI is a feasible method for increasing MI skills in parents. Additional research is needed to better understand the unique application of MI to parent-child interactions.

The distribution of self-reported psychotic-like experiences in non-psychotic help-seeking mental health patients in the general population; a factor mixture analysis.

PURPOSE: Factor mixture analysis (FMA) and item response mixture models in the general population have shown that the psychosis phenotype has four classes. This study attempted to replicate this finding in help-seeking people accessing mental health services for symptoms of non-psychotic mental disorders. METHODS: All patients (18-35 years old) referred for non-psychotic mental health problems to the secondary mental healthcare service in The Hague between February 2008 to February 2010 (N = 3,694), were included. Patients completed the Prodromal Questionnaire (PQ). Hybrid latent class analysis was applied to explore the number, size and symptom profiles of the classes. RESULTS: The FMA resulted in four classes. Class 1 (N = 1,039, 28.1%) scored high on conceptual disorganization, inattention and mood disorder. Patients in Class 2 (N = 619, 16.8%) endorsed almost all PQ-items, were more often screened as being psychotic or at high risk of developing psychosis, without care takers noticing. In Class 3 (N = 1,747, 47.3%) perplexity, paranoia and negative symptoms were more prevalent. Patients were more often at high risk of developing psychosis. Class 4 (N = 286, 7.7%) represented the 'normative' group with low probabilities for all items. DISCUSSION: The results support the hypothesis that a representation in four classes of psychotic-like experiences can also be applied in a help-seeking population.

Psychosis prediction: stratification of risk estimation with information-processing and premorbid functioning variables.

BACKGROUND: The period preceding the first psychotic episode is regarded as a promising period for intervention. We aimed to develop an optimized prediction model of a first psychosis, considering different sources of information. The outcome of this model may be used for individualized risk estimation. METHODS: Sixty-one subjects clinically at high risk (CHR), participating in the Dutch Prediction of Psychosis Study, were assessed at baseline with instruments yielding data on neuropsychology, symptomatology, environmental factors, premorbid adjustment, and neurophysiology. The follow-up period was 36 months. RESULTS: At 36 months, 18 participants (29.5%) had made a transition to psychosis. Premorbid adjustment (P = .001, hazard ratio [HR] = 2.13, 95% CI = 1.39/3.28) and parietal P300 amplitude (P = .004, HR = 1.27, 95% CI = 1.08/1.45) remained as predictors in the Cox proportional hazard model. The resulting prognostic score (PS) showed a sensitivity of 88.9% and a specificity of 82.5%. The area under the curve of the PS was 0.91 (95% CI = 0.83-0.98, cross-validation: 0.86), indicating an outstanding ability of the model to discriminate between transition and nontransition. The PS was further stratified into 3 risk classes establishing a prognostic index. In the class with the worst social-personal adjustment and lowest P300 amplitudes, 74% of the subjects made a transition to psychosis. Furthermore, transition emerged on average more than 17 months earlier than in the lowest risk class. CONCLUSIONS: Our results suggest that predicting a first psychotic episode in CHR subjects could be improved with a model including premorbid adjustment and information-processing variables in a multistep algorithm combining risk detection and stratification.