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The Prodromal Questionnaire (PQ) identifies psychiatric help-seekers in need of clinical interviews to diagnose psychosis risk. However, some providers use the PQ alone to identify risk. Therefore, we tested its predictive utility among 731 adolescent psychiatric help-seekers, with a 3-9-year register-based follow-up. Nine latent factors corresponded well with postulated subscales. Depersonalization predicted later hospitalization with a psychosis diagnosis (HR 1.6 per SD increase), and Role Functioning predicted any psychiatric hospitalization (HR 1.3). Published cut-off scores were poor predictors of psychosis; endorsement rates were very high for most symptoms. Therefore, we do not recommend using the PQ without second-stage clinical interviews., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Full-information factor analysis of ordinal data was employed to determine the factorial structure of the responses of 31,822 adult Swedish women to the 20 "positive" psychotic experience items of the Community Assessment of Psychic Experiences (CAPE) questionnaire. Five separable but correlated trait dimensions were found, reflecting Paranoia, Grandiosity, Magical Thinking, Delusions, and Hallucinations. High scores on any dimension were associated with a higher probability of questionnaire-assessed lifetime major depressive episodes or generalized anxiety disorder, though Grandiosity was so only to a very small degree. Our results closely match previous findings among adolescents and young women, and demonstrate that psychotic experiences cannot be considered a single trait., (Copyright © 2013 John Wiley & Sons, Ltd.)

Aim: Adolescents with severe disruptive behaviour have an elevated risk for adult psychosis. We investigated whether the Structured Interview for Prodromal Syndromes (SIPS) is a useful psychosis risk-screening tool for adolescents with disruptive behaviour., Method: Fifty-three adolescents residing in a reform school due to severe behavioural problems were interviewed with SIPS to ascertain clinical high-risk (CHR) state. CHR status was compared to self-reported psychiatric problems, and to registry data on hospital treatments for mental health disorders during a 5-year follow-up time., Results: CHR was associated with self-reported internalizing problems and thought problems. It failed to predict psychoses but was associated with hospital treatment for mood and conduct disorders., Conclusion: The SIPS interview has limited power for predicting psychosis among adolescents with severe behavioural problems. However, SIPS appears to be useful for screening and predicting other psychiatric problems., (© 2013 Wiley Publishing Asia Pty Ltd.)

Background: Delinquent adolescents are a known high-risk group for later criminality. Cognitive deficits correlate with adult criminality, and specific cognitive deficits might predict later criminality in the high-risk adolescents., Aims: This study aimed to explore the neuropsychological performance and predictors of adult criminal offending in adolescents with severe behavioural problems., Methods: Fifty-three adolescents (33 boys and 20 girls), aged 15-18 years, residing in a reform school due to serious conduct problems, were examined for neuropsychological profile and psychiatric symptoms. Results were compared with a same-age general population control sample, and used for predicting criminality 5 years after the baseline testing., Results: The reform school adolescents' neuropsychological performance was weak on many tasks, and especially on the verbal domain. Five years after the baseline testing, half of the reform school adolescents had obtained a criminal record. Males were overrepresented in both any criminality (75% vs. 10%) and in violent crime (50% vs. 5%). When cognitive variables, psychiatric symptoms and background factors were used as predictors for later offending, low verbal intellectual ability turned out to be the most significant predictor of a criminal record and especially a record of violent crime., Conclusions: Neurocognitive deficits, especially in the verbal and attention domains, are common among delinquent adolescents. Among males, verbal deficits are the best predictors for later criminal offending and violence., Clinical Implications: Assessing verbal abilities among adolescent population with conduct problems might prove useful as a screening method for inclusion in specific therapies for aggression management.

Background: Research has identified a syndrome conferring ultra-high risk (UHR) for psychosis, although UHR interviews require intensive staff training, time and patient burden. Previously, we developed the Prodromal Questionnaire (PQ) to screen more efficiently for UHR syndromes., Aims: This study examined the concurrent validity of the PQ against UHR status and preliminary predictive validity for later psychotic disorder., Method: We assessed a consecutive patient sample of 408 adolescents who presented to psychiatry clinics in Helsinki, Finland, seeking mental health treatment, including 80 participants who completed the Structured Interview for Prodromal Syndromes (SIPS)., Results: A cut-off score of 18 or more positive symptoms on the PQ predicted UHR diagnoses on the SIPS with 82% sensitivity and 49% specificity. Three of 14 (21%) participants with high PQ scores and SIPS UHR diagnoses developed full psychotic disorders within 1 year., Conclusions: Using the PQ and SIPS together can be an efficient two-stage screening process for prodromal psychosis in mental health clinics., (© 2011 Blackwell Publishing Asia Pty Ltd.)

Aim: Specialized self-report questionnaires have been developed for detection of symptoms indicative of psychosis risk. The identification of at-risk individuals is typically based on sum scores, which assume equal severity and discriminability of all symptoms, and a single dimension of illness. Our aim was to test whether separable dimensions of risk could be identified in the general population., Methods: We explored the latent structure of one such questionnaire using full-information item factor analysis, deriving exploratory models from the PROD-Screen questionnaire responses of the adolescent general population based on the Northern Finland 1986 Birth Cohort (n=6611)., Results: A three-dimensional factor structure of positive, negative and general symptoms emerged. The factor structure, the appropriateness of the statistical model and the application of the results to the detection of heightened psychosis risk are discussed., Conclusions: In explicitly taking into account the multidimensionality and varying symptom severity of the included items, the current model provides an improvement in questionnaire-based assessment of psychosis risk., (© 2011 Blackwell Publishing Asia Pty Ltd.)

Objective: Our aim was to study the association between psychotic-like symptoms and inattention/hyperactivity symptoms in a general adolescent population., Subjects and Methods: The sample is based on a population-based prospective mother-child birth cohort, the Northern Finland Birth Cohort 1986. In the 15-16-year follow-up survey, the adolescents completed the Youth Self-Report questionnaire as well as the PROD-Screen questionnaire that addressed prodromal symptoms of psychosis. Meanwhile, their parents assessed inattention and hyperactive symptoms of their offspring by completing the Strengths and Weaknesses of ADHD Symptoms and Normal Behaviors questionnaire (N = 5,318). The cross-sectional associations between psychotic-like symptoms and inattention/hyperactivity symptoms were studied with logistic regression models., Results: The association between negative psychotic-like symptoms and inattention symptoms, especially the dreamy type of inattention symptoms (e.g., difficulties in organizing tasks, losing things, being forgetful), was statistically significant for both genders. Psychotic-like symptoms, however, were not associated with hyperactivity symptoms., Conclusions: The present findings demonstrate that an association between psychotic-like symptoms and attentional dysfunction, which has been found in clinical samples, is also present in a general adolescent population.

Introduction: The current criteria for detecting a Clinical High-Risk (CHR) state for psychosis do not address cognitive impairment. A first step for identifying cognitive markers of psychosis risk would be to determine which aspects of neurocognitive performance are related with more severe psychotic-like symptoms. This study assessed cognitive impairment associated with prodromal symptoms in adolescents receiving public psychiatric treatment., Methods: 189 adolescents were recruited from consecutive new patients aged 15-18 attending mainly outpatient adolescent psychiatric units in Helsinki. They had been screened for prodromal symptoms using the Prodromal Questionnaire, and all screen-positives as well as a random sample of screen-negatives were interviewed using the Structured Interview for Prodromal Symptoms (SIPS) and underwent testing using a large, standardized neurocognitive test battery. The sample included 62 adolescents who met the CHR criteria (CHR) and 112 who did not (non-CHR). A healthy control sample (n=72) was also included to provide age- and gender-matched norms., Results: The CHR group performed worse on visuospatial tasks than the non-CHR group. Among CHR adolescents, negative symptoms were associated with slower processing speed and poorer performance on verbal tasks. Among non-CHR adolescents, positive symptoms were associated with poorer performance on visuospatial tasks, and negative symptoms with poorer performance on verbal tasks., Conclusion: Clinical high-risk status is associated with impaired visuospatial task performance. However, both positive, psychotic-like symptoms and negative symptoms are associated with lower levels of neurocognitive functioning among adolescents in psychiatric treatment regardless of whether CHR criteria are met. Thus, even mild positive and negative symptoms may have clinical relevance in adolescents in psychiatric care. Adolescents with both psychotic-like symptoms and neurocognitive deficits constitute a group requiring special attention., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Early intervention may postpone or even prevent the onset of psychosis and relieve symptom-related anxiety. Support and follow-up observation requires up-to-date knowledge of the nature of the risk symptoms of psychosis and of the therapy of the person having symptoms within the healthcare system. Healthcare professionals should be aware of the limitations of present research information in order to assess the correct magnitude of the risk of psychosis. Although a person assigned by current methods to the risk group presents a higher than tenfold risk compared with the rest of the population, improvement of prognostic accuracy remains as the central research issue.

It has been proposed that patients with schizophrenia and some of their relatives suffer from reduced neurocognitive efficiency, increasing their sensitivity to experimental task demands. The present study evaluated such a possibility during performance of a working memory task by schizophrenia patients and their co-twins along with a healthy control sample. Electrophysiological data were obtained from sets of nine twin pairs (monozygotic and dizygotic pairs collapsed) discordant for a diagnosis of schizophrenia and from nine matched healthy control twin pairs, during administration of a variable-load spatial working memory task. Event-related potentials (ERPs) were measured immediately after memory set onset and during a delay period. For correctly performed trials, slow-wave ERP activity measured during the late stimulus encoding and delay periods exhibited a significant Diagnostic Group-by-Memory Load interaction, with schizophrenia patients showing a differentially strong load effect. Patients' co-twins displayed an intermediate level of load sensitivity while healthy controls showed no significant load effect. These results support an inefficiency model of neurocognitive dysfunction in schizophrenia, a pattern that appears to be related to the pathogenesis and inheritance of the disorder. Furthermore, this inefficiency appeared during the late stimulus encoding stage of working memory functioning, possibly reflecting disruptions in stimulus representation consolidation.

Background: The present analyses aimed to test the prediction that schizophrenia patients and their non-schizophrenic co-twins would display reduced efficiency of the neurocognitive mechanisms subserving active maintenance of spatial information in working memory., Methods: Upper alpha frequency band EEG event-related desynchronization and synchronization (ERD/ERS) were calculated as percent changes in power relative to an inter-trial baseline across 4 memory loads in a spatial delayed-response task., Results: During the delay, the diagnostic groups showed equivalent ERD/ERS activity over posterior scalp regions at the lowest memory load; however, as memory load increased, patients, and to an intermediate degree, their non-schizophrenic co-twins (monozygotic and dizygotic pairs collapsed together), showed significantly greater increases in ERD/ERS amplitude as compared with controls., Conclusions: These findings demonstrate abnormally increased ERD/ERS amplitudes with increasing memory load in patients with schizophrenia and their co-twins, consistent with inefficiency of the neurocognitive mechanisms supporting active maintenance of information across a delay.

The nature, neural underpinnings, and etiology of deficits in verbal declarative memory in patients with schizophrenia remain unclear. To examine the contributions of genes and environment to verbal recall and recognition performance in this disorder, the California Verbal Learning Test was administered to a large population-based Finnish twin sample, which included schizophrenic and schizoaffective patients, their non-ill monozygotic (MZ) and dizygotic (DZ) co-twins, and healthy control twins. Compared with controls, patients and their co-twins showed relatively greater performance deficits on free recall compared with recognition. Intra-pair differences between patients and their non-ill co-twins in hippocampal volume and memory performance were highly positively correlated. These findings are consistent with the view that genetic influences are associated with reduced verbal recall in schizophrenia, but that non-genetic influences further compromise these abnormalities in patients who manifest the full-blown schizophrenia phenotype, with this additional degree of disease-related declarative memory deficit mediated in part by hippocampal pathology.

While behavioral research shows working memory impairments in schizophrenics and their relatives, functional neuroimaging studies of patients and healthy controls show conflicting findings of hypo- and hyperactivation, possibly indicating different relationships between physiological activity and performance. In a between-subjects regression analysis of fMRI activation and performance, low performance was associated with relatively lower activation in patients than controls, while higher performance was associated with higher activation in patients than controls in DLPFC and parietal cortex, but not occipital cortex, with unaffected twins of schizophrenics being intermediate between the groups. Accordingly, this supports the idea that both hyper and hypoactivation may be possible along a continuum of behavioral performance in a way consistent with a neural inefficiency model. Further, this study offers preliminary evidence that the relationship between behavior and physiology in schizophrenia may be heritable.

Background: Information on the inheritance of neurophysiological abnormalities might help elucidate the molecular genetic basis of schizophrenia. We used magnetoencephalography (MEG) and electroencephalography (EEG) to investigate the inheritance of auditory-cortical deficiencies in twin pairs discordant for schizophrenia., Methods: Auditory EEG/MEG responses to frequent standard and occasional deviant tones were measured in mono- and dizygotic (MZ and DZ) twin pairs discordant for schizophrenia and demographically matched healthy twin pairs, recruited from a total population cohort. The MEG/EEG results were regressed against the genetic resemblance to patients with schizophrenia across the patients' unaffected MZ/DZ co-twins and control subjects (with genetic correlations of 1, .5, and 0 to schizophrenia patients, respectively)., Results: The EEG responses P50, N100, and mismatch negativity (MMN), as well as the MEG response P50m, were reduced in the schizophrenic patients. P50 and N100 were significantly decreased also in their unaffected co-twins, as compared with the control subjects. Importantly, the P50 and N100 decrease correlated with the unaffected subjects' genetic resemblance to schizophrenia patients., Conclusions: Our results suggest inherited abnormalities in cortical auditory processing in schizophrenia, reflected by the decreased P50/P50m and N100 amplitudes, whereas the MMN abnormalities might reflect predominantly state-dependent neurodegeneration.

Background: Spatial working memory impairments are among the neurocognitive deficits that may mark genetic predisposition toward schizophrenia. We previously reported that impairment on the spatial span subtask of the Wechsler Adult Intelligence Scale-Revised increased in a dose-dependent manner with increasing genetic predisposition toward schizophrenia in a sample of discordant twins; however, it remains to be determined whether these deficits reflect difficulties with encoding, maintenance, manipulation, time-tagging of visual spatial information, storage capacity, or complex motor response., Methods: We developed a spatial delayed response task in which memory set size was parametrically varied, holding constant manipulation and decision processes. We then reassessed 80 of the previously studied twins (17 probands with 8 monozygotic co-twins and 13 dizygotic co-twins, and 42 healthy twins)., Results: The spatial delayed response task was sensitive to genetic loading for schizophrenia but did not provide evidence for capacity limitations in probands or their co-twins., Conclusions: The findings suggest that deficits in the encoding or storage aspects of short-term spatial mnemonic processing may be an effective endophenotypic marker for schizophrenia.