Subclinical psychotic experiences and cognitive functioning as a bivariate phenotype for genetic studies in the general population

Pathways linking school bullying and psychotic experiences: Multiple mediation analysis in Chinese adolescents and young adults

It is found that people with psychotic experiences have a 4-fold increased risk of developing a psychotic disorder later in life. Indeed, accumulating evidence has suggested that the association between school bullying and psychotic experiences works linearly. Previous studies are mainly carried out in a Western context, and only seldomly do studies address whether the association exists in the Chinese population and the related psychological and cognitive mechanisms. Therefore, we carried out the current study to address this gap in the literature focusing on the lifelong school bullying experiences of Chinese adolescents and young adults. We examined them in relation to psychotic experiences while assessing the mediating role of self-esteem, the personality trait of neuroticism, and a cognitive bias in thinking called interpretation bias. We found that multiple victimizations were quite common in Hong Kong secondary schools. In addition to a significant association between school bullying and psychotic experiences, we found partial mediating effects of proposed psychological and cognitive mediators in constructed multiple mediation models utilizing bootstrapping approach. Specifically, bullying quantity reflecting the number of victimizations, had its association with psychotic experiences partially mediated by the personality trait of neuroticism. In contrast, bullying duration reflecting the lasting of victimization was associated with psychotic experiences partially mediated by the personality trait of neuroticism and interpretation bias. Our findings enhance our knowledge of mechanisms underpinning the psychosis spectrum development and have implications for school-based intervention programs targeting bullying victims.

Psychomotor Slowing in Schizophrenia: Implications for Endophenotype and Biomarker Development

Motor abnormalities (e.g., dyskinesia, psychomotor slowing, neurological soft signs) are core features of schizophrenia that occur independent of drug treatment and are associated with the genetic vulnerability and pathophysiology for the illness. Among this list, psychomotor slowing in particular is one of the most consistently observed and robust findings in the field. Critically, psychomotor slowing may serve as a uniquely promising endophenotype and/or biomarker for schizophrenia considering it is frequently observed in those with genetic vulnerability for the illness, predicts transition in subjects at high-risk for the disorder, and is associated with symptoms and recovery in patients. The purpose of the present review is to provide an overview of the history of psychomotor slowing in psychosis, discuss its possible neural underpinnings, and review the current literature supporting slowing as a putative endophenotype and/or biomarker for the illness. This review summarizes substantial evidence from a diverse array of methodologies and research designs that supports the notion that psychomotor slowing not only reflects genetic vulnerability, but is also sensitive to disease processes and the pathophysiology of the illness. Furthermore, there are unique deficits across the cognitive (prefix "psycho") and motor execution (root word "motor") aspects of slowing, with cognitive processes such as planning and response selection being particularly affected. These findings suggest that psychomotor slowing may serve as a promising endophenotype and biomarker for schizophrenia that may prove useful for identifying individuals at greatest risk and tracking the course of the illness and recovery.

Twin studies of brain structure and cognition in schizophrenia

Twin studies in schizophrenia have been crucial in establishing estimates for the heritability and thus providing evidence for a genetic component in this disorder. Recent years have seen the application of the twin study paradigm to both putative intermediate phenotypes and biomarkers of disease as well as a diversification of its use in schizophrenia research. This review addressed studies of brain structure (T1 morphometry) and cognition in schizophrenia using twin study designs. We review major findings such as the overlap of genetic variance between schizophrenia and cognition as a model for the emergence of psychopathology. The use of novel hybrid models integrating molecular genetic risk markers, as well as the use of twin studies in epigenetics might prove to significantly enhance schizophrenia research in the post-GWAS era.

Self-reported cognitive distortions in the psychosis continuum: A Polish 18-item version of the Davos Assessment of Cognitive Biases Scale (DACOBS-18)

AIM

The aim of this study was to provide a short version of the Davos Assessment of Cognitive Biases Scale (DACOBS), which is a self-report tool to assess cognitive distortions related to psychosis.

METHODS

A principal component analysis (PCA) was conducted on a large non-clinical sample (n=1207) and cross-validated with a confirmatory factor analysis on an independent non-clinical sample (n=653). Discriminative validity was performed by contrasting the high risk for psychosis non-clinical sample (n=63), low risk for psychosis non-clinical sample (n=152), patients with schizophrenia (n=105), and patients with depression (n=56). Correlations between symptoms, cognitive functions, source monitoring deficits, and jumping to conclusions were performed among a subgroup of patients with schizophrenia.

RESULTS

An 18-item scale (DACOBS-18) with a four-factor solution was established. Internal consistency (α=0.84) and test-retest reliability (r=0.84, p<0.001) were good. The DACOBS-18 has satisfactory discriminative power, with 99.1% sensitivity and 74.3% specificity in discriminating low risk for psychosis from schizophrenia patients. The DACOBS-18 subscales correlate significantly with psychotic symptoms and psychotic-like experiences. After Bonferroni correction, significant correlations between Safety Behaviors and neuropsychological functioning were found.

CONCLUSIONS

The DACOBS-18 is a reliable scale with satisfactory discriminative power and thus may be a valuable self-report screening tool for use in everyday clinical practice with psychotic patients and with people at risk for psychosis. Further research on its relationship to objective cognitive measures is needed.

Mistiming of thought and perception predicts delusionality

The timing of thoughts and perceptions plays an essential role in belief formation. Just as people can experience in-the-moment perceptual illusions, however, they can also be deceived about how events unfold in time. Here, we consider how a particular type of temporal distortion, in which the apparent future influences "earlier" events in conscious awareness, might affect people's most fundamental beliefs about themselves and the world. Making use of a task that has been shown to elicit such reversals in the temporal experience of prediction and observation, we find that people who are more prone to think that they predicted an event that they actually already observed are also more likely to report holding delusion-like beliefs. Moreover, this relationship appears to be specific to how people experience prediction and is not explained by domain-general deficits in temporal discrimination. These findings may help uncover low-level perceptual mechanisms underlying delusional belief or schizotypy more broadly and may ultimately prove useful as a tool for identifying those at risk for psychotic illness.

Neural markers of emotional face perception across psychotic disorders and general population

There is considerable variation in negative and positive symptoms of psychosis, global functioning, and emotional face perception (EFP), not only in schizophrenia but also in other psychotic disorders and healthy individuals. However, EFP impairment and its association with worse symptoms and global functioning have been examined largely in the domain of schizophrenia. The present study adopted a dimensional approach to examine the association of behavioral and neural measures of EFP with symptoms of psychosis and global functioning across individuals with schizophrenia spectrum (SZ; N = 28) and other psychotic (OP; N = 29) disorders, and never-psychotic participants (NP; N = 21). Behavioral and functional MRI data were recorded as participants matched emotional expressions of faces and geometrical shapes. Lower accuracy and increased activity in early visual regions, hippocampus, and amygdala during emotion versus shape matching were associated with higher negative, but not positive, symptoms and lower global functioning, across all participants. This association remained even after controlling for group-related (SZ, OP, and NP) variance, dysphoria, and antipsychotic medication status, except in amygdala. Furthermore, negative symptoms mediated the relationship between behavioral and brain EFP measures and global functioning. This study provides some of the first evidence supporting the specific relationship of EFP measures with negative symptoms and global functioning across psychotic and never-psychotic samples, and transdiagnostically across different psychotic disorders. Present findings help bridge the gap between basic EFP-related neuroscience research and clinical research in psychosis, and highlight EFP as a potential symptom-specific marker that tracks global functioning. (PsycINFO Database Record

The impact of loneliness on paranoia: An experimental approach

BACKGROUND AND OBJECTIVES

Loneliness is a common problem in patients with schizophrenia, and may be particularly linked with persecutory ideation. Nevertheless, its role as a potential risk factor in the formation and maintenance of persecutory delusions is largely unexplored.

METHODS

Loneliness was experimentally manipulated using a false-feedback paradigm in a non-clinical sample (n = 60). Change in state paranoia was compared between the induction of increased loneliness, the induction of reduced loneliness and a control condition. Distinct associations between pre-post scores of loneliness and state paranoia were examined at three (medium/high/low) levels of proneness to psychosis across the experimental conditions.

RESULTS

Reduction of loneliness was associated with a significant reduction of present paranoid beliefs, while induction of loneliness lead to more pronounced paranoia on trend significance level. Moreover, proneness to psychosis significantly moderated the impact of loneliness on paranoia. Persons with a pronounced level of proneness to psychosis showed a stronger reduction of paranoid beliefs as a consequence of a decrease in loneliness, than less prone individuals.

LIMITATIONS

A limitation is the small size of our sample, which may have limited the power to detect significant within-group changes in state paranoia in the high-loneliness condition and changes in loneliness in the low-loneliness condition.

CONCLUSIONS

The findings support the feasibility of the experimental design to manipulate loneliness and suggest that loneliness could be a cause of paranoia. However, the findings need to be confirmed in high risk samples to draw conclusions about the role of loneliness in the genesis of clinically relevant levels of paranoia and derive implications for cognitive behaviour therapy.

Sun Exposure and Psychotic Experiences

OBJECTIVE

Sun exposure is considered the single most important source of vitamin D. Vitamin D deficiency has been suggested to play a role in the etiology of psychotic disorders. The aim of the present study was to evaluate the association between sun exposure and psychotic experiences (PEs) in a general population sample of Swedish women.

METHODS

The study population included participants from The Swedish Women's Lifestyle and Health cohort study. The 20-item community assessment of psychic experiences (CAPEs) was administered between ages 30 and 50 to establish PEs. Sun exposure as measured by (1) sunbathing holidays and (2) history of sunburn was measured between ages 10 and 39. The association between sun exposure and PEs was evaluated by quantile regression models.

RESULTS

34,297 women were included in the analysis. Women who reported no sunbathing holidays and 2 or more weeks of sunbathing holidays scored higher on the CAPE scale than women exposed to 1 week of sunbathing holidays across the entire distribution, when adjusting for age and education. Similarly, compared with women who reported a history of one sunburn, the women with none or two or more sunburns showed higher scores on the CAPE scale.

CONCLUSION

The results of the present study suggest that, in a population-based cohort of middle aged women, both low and high sun exposure is associated with increased level of positive PEs.

Cingulo-opercular network efficiency mediates the association between psychotic-like experiences and cognitive ability in the general population

BACKGROUND

Psychosis is hypothesized to occur on a spectrum between psychotic disorders and healthy individuals. In the middle of the spectrum are individuals who endorse psychotic-like experiences (PLEs) that may not impact daily functioning or cause distress. Individuals with PLEs show alterations in both cognitive ability and functional connectivity of several brain networks, but the relationship between PLEs, cognition, and functional networks remains poorly understood.

METHODS

We analyzed resting-state fMRI data, a range of neuropsychological tasks, and questions from the Achenbach Adult Self Report (ASR) in 468 individuals from the Human Connectome Project. We aimed to determine whether global efficiency of specific functional brain networks supporting higher-order cognition (the fronto-parietal network (FPN), cingulo-opercular network (CON), and default mode network (DMN)) was associated with PLEs and cognitive ability in a non-psychiatric sample.

RESULTS

21.6% of individuals in our sample endorsed at least one PLE. PLEs were significantly negatively associated with higher-order cognitive ability, CON global efficiency, and DMN global efficiency, but not crystallized knowledge. Higher-order cognition was significantly positively associated with CON and DMN global efficiency. Interestingly, the association between PLEs and cognitive ability was partially mediated by CON global efficiency and, in a subset of individuals who tested negative for drugs (N=405), the participation coefficient of the right anterior insula (a hub within the CON).

CONCLUSIONS

These findings suggest that CON integrity may represent a shared mechanism that confers risk for psychotic experiences and the cognitive deficits observed across the psychosis spectrum.

Association between electroencephalographic modulation, psychotic-like experiences and cognitive performance in the general population

AIM

An association between deficit of electroencephalographic (EEG) modulation during an odd-ball task and psychotic symptoms has been described in clinical samples, in agreement with the proposed role for altered salience in psychosis. To discard the possible influence of medication, the relationship between psychotic-like experiences and EEG modulation in the general population was explored.

METHODS

EEG and psychotic-like experiences were assessed in 194 healthy subjects during a P300 paradigm. EEG modulation was assessed as changes from pre-stimulus to response windows in spectral entropy (SE, a measurement of signal irregularity), median frequency (MF, a quantifier of the frequency distribution of oscillatory activity) and theta, alpha, beta-1, beta-2 and gamma relative power (RP, a summary of the distribution of spectral components).

RESULTS

A significant widespread decrease in SE and MF from baseline to response was found, with a significant increase in RP for theta and a decrease for higher frequency bands, supporting an increase in EEG regularity and a slowing of brain oscillations during the response. Furthermore, a significant association was found between SE modulation and distress of negative psychotic-like experiences, as well as between verbal memory and RP modulation for beta-1. Performance in verbal fluency was associated with the increase in theta RP during the response.

CONCLUSION

EEG irregularity of healthy subjects decreased at the expense of a larger contribution of theta RP and a decreased contribution of fast frequency bands. Subjects with smaller modulation showed poorer cognitive scores and greater distress of negative psychotic-like experiences.

[Relationship between subclinical psychotic symptoms and cognitive performance in the general population]

INTRODUCTION

Subclinical psychotic symptoms are associated to negative life outcomes in the general population, but their relationship with cognitive performance is still not well understood. Assessing the relationship between performance in cognitive domains and subclinical psychotic symptoms in the general population may also help understand the handicap attributed to clinical psychosis, in which these alterations are present.

METHODS

Subclinical and cognitive assessments were obtained in 203 participants from the general population by means of the Community Assessment of Psychic Experiences, the Brief Assessment of Cognition in Schizophrenia, the Wechsler Adults Intelligence Scale and the Wisconsin Card Sorting Test. The positive and negative subclinical symptoms and their relationship with age and cognition were examined, followed by assessing the influence of subclinical depression scores on the possible relationships between those subclinical psychotic symptoms and cognitive deficits.

RESULTS

Inverse relationships were found between frequency in the Community Assessment of Psychic Experiences positive dimension and motor speed, and frequency and distress in the Community Assessment of Psychic Experiences negative dimension and motor speed. A direct relationship was also found between distress scores of the positive dimension and executive functions. Both positive and negative subclinical symptoms were related to depression scores.

CONCLUSIONS

Psychotic symptoms, similar to those in the clinical population, may be associated with cognitive deficits in the general population.

Reduced brain reward response during cooperation in first-degree relatives of patients with psychosis: an fMRI study

BACKGROUND

Psychosis is characterized by a profound lack of trust and disturbed social interactions. Investigating the neural basis of these deficits is difficult because of medication effects but first-degree relatives show qualitatively similar abnormalities to patients with psychosis on various tasks. This study aimed to investigate neural activation in siblings of patients in response to an interactive task. We hypothesized that, compared to controls, siblings would show (i) less basic trust at the beginning of the task and (ii) reduced activation of the brain reward and mentalizing systems.

METHOD

Functional magnetic resonance imaging (fMRI) data were acquired on 50 healthy siblings of patients with psychosis and 33 healthy controls during a multi-round trust game with a cooperative counterpart. An a priori region-of-interest (ROI) analysis of the caudate, temporoparietal junction (TPJ), superior temporal sulcus (STS), insula and medial prefrontal cortex (mPFC) was performed focusing on the investment and repayment phases. An exploratory whole-brain analysis was run to test for group-wise differences outside these ROIs.

RESULTS

The siblings' behaviour during the trust game did not differ significantly from that of the controls. At the neural level, siblings showed reduced activation of the right caudate during investments, and the left insula during repayments. In addition, the whole-brain analysis revealed reduced putamen activation in siblings during investments.

CONCLUSIONS

The findings suggest that siblings show aberrant functioning of regions traditionally involved in reward processing in response to cooperation, which may be associated with the social reward deficits observed in psychosis.

POSITIVE AND NEGATIVE SUBCLINICAL SYMPTOMS AND MCCB PERFORMANCE IN NON-PSYCHIATRIC CONTROLS

Considerable data support the phenomenological and temporal continuity between subclinical psychosis and psychotic disorders. In recent years, neurocognitive deficits have increasingly been recognized as a core feature of psychotic illness but there are few data seeking to elucidate the relationship between subclinical psychosis and neurocogntive deficits in non-clinical samples. The goal of the present study was to examine the relationship between subclinical positive and negative symptoms, as measured by the Community Assessment of Psychic Experiences (CAPE) and performance on the MATRICS Consensus Cognitive Battery (MCCB) in a large (n = 303) and demographically diverse non-clinical sample. We found that compared to participants with low levels of subclinical positive symptoms, participants with high levels of subclinical positive symptoms performed significantly better in the domains of working memory (p < .001), verbal learning (p = .007) and visual learning (p = .014). Although comparison of participants with high and low levels of subclinical negative symptoms revealed no differences in MCCB performance, we found that individuals with high levels of subclinical negative symptoms performed significantly better on a measure of estimated IQ (WRAT-3 Reading subtest; p = .02) than those with low levels of subclinical negative symptoms. These results are at odds with prior reports that have generally shown a negative relationship between neurocognitive functioning and severity of subclinical psychotic symptoms, and suggest some potential discontinuities between clinically significant psychotic symptoms and sub-syndromal manifestations of psychosis.

Response initiation in young adults at risk for psychosis in the Northern Finland 1986 Birth Cohort

INTRODUCTION

This is one of the very few studies to investigate the specific executive function/processing speed component of response initiation in subjects at familial risk (FR) for psychosis, and the first such study in subjects at clinical risk (CR) for psychosis.

METHODS

Participants (N = 177) were members of the general population-based Northern Finland 1986 Birth Cohort in the following four groups: FR for psychosis (n = 62), CR for psychosis (n = 21), psychosis (n = 25) and control subjects (n = 69). The response initiation of these groups was compared in three different tests: Semantic fluency, Stockings of Cambridge and Spatial working memory.

RESULTS

The two risk groups did not differ significantly from control group, but differed from, and outperformed the psychosis group in semantic fluency response initiation.

CONCLUSIONS

Response initiation deficits were not evident in a non-help seeking psychosis high-risk sample.

Subclinical psychotic experiences and bipolar spectrum features in depression: association with outcome of psychotherapy

BACKGROUND

Subthreshold psychotic and bipolar experiences are common in major depressive disorder (MDD). However, it is unknown if effectiveness of psychotherapy is altered in depressed patients who display such features compared with those without. The current paper aimed to investigate the impact of the co-presence of subclinical psychotic experiences and subclinical bipolar symptoms on the effectiveness of psychological treatment, alone or in combination with pharmacotherapy.

METHOD

In a naturalistic study, patients with MDD (n = 116) received psychological treatment (cognitive behavioural therapy or interpersonal psychotherapy) alone or in combination with pharmacotherapy. Depression and functioning were assessed six times over 2 years. Lifetime psychotic experiences and bipolar symptoms were assessed at the second time point.

RESULTS

Subclinical psychotic experiences predicted more depression over time (β = 0.20, p < 0.002), non-remission [odds ratio (OR) 7.51, p < 0.016] and relapse (OR 3.85, p < 0.034). Subthreshold bipolar symptoms predicted relapse (OR 1.16, p < 0.037).

CONCLUSIONS

In general, subclinical psychotic experiences have a negative impact on the course and outcome of psychotherapy in MDD. Effects of subclinical bipolar experiences were less prominent.

Self-perception but not peer reputation of bullying victimization is associated with non-clinical psychotic experiences in adolescents

BACKGROUND

Bullying victimization may be linked to psychosis but only self-report measures of victimization have been used so far. This study aimed (a) to investigate the differential associations of peer-nominated versus self-reported victim status with non-clinical psychotic experiences in a sample of young adolescents, and (b) to examine whether different types of self-reported victimization predict non-clinical psychotic experiences in these adolescents. Method A combination of standard self-report and peer nomination procedures was used to assess victimization. The sample (n = 724) was divided into four groups (exclusively self-reported victims, self- and peer-reported victims, exclusively peer-reported victims, and non-victims) to test for a group effect on non-clinical psychotic experiences. The relationship between types of victimization and non-clinical psychotic experiences was examined by a regression analysis.

RESULTS

Self-reported victims, along with self- and peer-reported victims, scored higher than peer-reported victims and non-victims on non-clinical psychotic experiences. Self-reports of direct relational, indirect relational and physical victimization significantly improved the prediction of non-clinical psychotic experiences whereas verbal and possession-directed victimization had no significant predictive value.

CONCLUSIONS

The relationship between victimization and non-clinical psychotic experiences is only present for self-reported victimization, possibly indicative of an interpretation bias. The observed discrepancy between self-report and peer-report highlights the importance of implementing a combination of both measures for future research.

Altered transfer of momentary mental states (ATOMS) as the basic unit of psychosis liability in interaction with environment and emotions

Psychotic disorders are thought to represent altered neural function. However, research has failed to map diagnostic categories to alterations in neural networks. It is proposed that the basic unit of psychotic psychopathology is the moment-to-moment expression of subtle anomalous experiences of subclinical psychosis, and particularly its tendency to persist from moment-to-moment in daily life, under the influence of familial, environmental, emotional and cognitive factors.

In a general population twin sample (n = 579) and in a study of patients with psychotic disorder (n = 57), their non-psychotic siblings (n = 59) and unrelated controls (n = 75), the experience sampling paradigm (ESM; repetitive, random sampling of momentary mental states and context) was applied. We analysed, in a within-person prospective design, (i) transfer of momentary anomalous experience at time point (t–1) to time point (t) in daily life, and (ii) moderating effects of negative affect, positive affect, daily stressors, IQ and childhood trauma. Additionally, (iii) familial associations between persistence of momentary anomalous experience and psychotic symptomatology were investigated. Higher level of schizotypy in the twins (but not higher level of psychotic symptoms in patients) predicted more persistence of momentary anomalous experience in daily life, both within subjects and across relatives. Persistence of momentary anomalous experience was highest in patients, intermediate in their siblings and lowest in controls. In both studies, persistence of momentary anomalous experience was moderated by higher levels of negative affect, daily stressors and childhood trauma (only in twins), and by lower levels of positive affect. The study of alterations in the moment-to-moment transfer of subtle anomalous experience of psychosis, resulting in their persistence, helps to explain why psychotic and emotional dysregulation tend to cluster in a single phenotype such as schizophrenia, and how familial and environmental risks increase the risk of expression of psychosis from, first, subtle momentary anomalous experience to, second, observable clinical symptoms.

Insight, symptomatic dimensions, and cognition in patients with acute-phase psychosis

AIMS

This study was designed to evaluate the relationship between insight and the severity of psychotic symptomatology in a sample of patients in an acute phase of psychosis, as well as to analyze the relationship between insight and the symptomatic profile of the patient. In addition, the role of general cognitive abilities in this relationship was explored.

METHOD

Cross-sectional observational study of 96 acute psychotic adults. To evaluate psychopathology we used the Positive and Negative Syndrome Scale; for insight, the Scale of Unawareness of Mental Disorder; and for general cognitive abilities, the Screen for Cognitive Impairment in Psychiatry.

RESULTS

Insight showed significant and moderate positive correlations with positive and general symptoms but not with negative symptoms. In the subgroup with positive symptomatic profile, awareness of the disorder and of the effects of medication were positively associated with severity of positive and general psychotic symptoms. Awareness of social consequences of the disease was positively associated with positive symptoms. In the subgroup with a negative symptomatic profile, awareness of the disorder and of the effects of medication were positively associated with severity of positive and general psychotic symptoms. In this subgroup, these relationships were significantly affected by general cognitive abilities.

CONCLUSIONS

Insight was not related with the severity of negative psychotic symptoms. The symptomatic profile of subjects played an important role in determining the relationship between insight and its dimensions and the severity of psychotic symptoms. Cognitive function moderated these relationships only in the negative symptomatic profile.

Are screening instruments valid for psychotic-like experiences? A validation study of screening questions for psychotic-like experiences using in-depth clinical interview

Individuals who report psychotic-like experiences are at increased risk of future clinical psychotic disorder. They constitute a unique "high-risk" group for studying the developmental trajectory to schizophrenia and related illnesses. Previous research has used screening instruments to identify this high-risk group, but the validity of these instruments has not yet been established. We administered a screening questionnaire with 7 items designed to assess psychotic-like experiences to 334 adolescents aged 11-13 years. Detailed clinical interviews were subsequently carried out with a sample of these adolescents. We calculated sensitivity and specificity and positive predictive value (PPV) and negative predictive value (NPV) for each screening question for the specific symptom it enquired about and also in relation to any psychotic-like experience. The predictive power varied substantially between items, with the question on auditory hallucinations ("Have you ever heard voices or sounds that no one else can hear?") providing the best predictive power. For interview-verified auditory hallucinations specifically, this question had a PPV of 71.4% and an NPV of 90.4%. When assessed for its predictive power for any psychotic-like experience (including, but not limited to, auditory hallucinations), it provided a PPV of 100% and an NPV of 88.4%. Two further questions-relating to visual hallucinations and paranoid thoughts-also demonstrated good predictive power for psychotic-like experiences. Our results suggest that it may be possible to screen the general adolescent population for psychotic-like experiences with a high degree of accuracy using a short self-report questionnaire.

Associations between psychotic-like symptoms and inattention/hyperactivity symptoms

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.

The relationship between psychotic-like symptoms and neurocognitive performance in a general adolescent psychiatric sample

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.

Investigation of clinical factors influencing cognitive function in Japanese schizophrenia

Several investigators have reported cognitive dysfunction in chronic schizophrenia that was associated with insight and social skills. Such cognitive dysfunction seriously hinders an immediate return to normal life. Recently, Kaneda et al. reported that the Brief Assessment of Cognition in Schizophrenia, Japanese-language version (BACS-J) was superior in the evaluation of the cognitive function. We investigated which clinical factors (age, sex, duration of illness, level of education, smoking status, the Positive and Negative Syndrome Scale (PANSS) score and medication dosage) affected cognitive dysfunction in 115 Japanese schizophrenic patients, with the use of multiple regression analysis. We detected an association between composite score, verbal memory, working memory and executive function and PANSS total score. Moreover, most cognitive tasks were associated with a negative PANSS score but not a positive PANSS score or general score. We also showed an association between age and verbal fluency and attention in schizophrenia. In addition, anxiolytics/hypnotics (diazepam-equivalent) were associated with composite score, working memory and motor speed. In conclusion, cognitive function was associated with PANSS score, especially negative PANSS score. Because anxiolytics/hypnotics might have a detrimental influence on cognitive function, we strongly suggest that the use of anxiolytics/hypnotics be reduced in schizophrenics as much as possible.

Evidence that self-reported psychotic experiences represent the transitory developmental expression of genetic liability to psychosis in the general population

It has been suggested that self-reported, common, non-clinical psychotic experiences may represent the transitory developmental expression of distributed genetic risk for psychosis. In a sample of female MZ (176 pairs) and DZ twins (113 pairs), cross-twin, cross-trait analyses were conducted to investigate the association between repeated continuous measures of self-reported psychotic experiences (PE-three measures over 18 months), assessed with the CAPE, in one twin and clinical interview categorical measures of psychotic symptoms (PS), assessed with SCID-I, in the other twin. The results showed that in MZ but not DZ pairs (interaction: chi(2) = 7.9, df = 1, P = 0.005), the cross-twin association between PE and PS was large and significant (standardized effect size: 0.26, 95% CI: 0.10-0.42) and of similar magnitude as the within-twin PE-PS association (standardized effect size: 0.28, 95% CI: 0.10-0.45), demonstrating both PE validity and genetic effects. In addition, the cross-twin association between PE and PS was significantly larger (interaction: chi(2) = 20.3, df = 1, P < 0.0001) for younger MZ twins (standardized effect size: 0.67, 95% CI: 0.44-0.90) than older MZ twins (standardized effect size: -0.05, 95% CI: -0.26 to 0.16), demonstrating developmental effects. This study indicates that self-reported psychotic experiences in the general population may represent the developmental expression of population genetic risk for psychosis.

Subjective experience of cognitive failures as possible risk factor for negative symptoms of psychosis in the general population

OBJECTIVE

The aim of this study was to examine whether proneness to subjective cognitive failure (cognitive based mistakes) increases the risk for the development of symptoms of psychosis and to what degree any association was familial.

METHODS

At baseline, the Cognitive Failure Questionnaire (CFQ) and the Community Assessment of Psychic Experiences (CAPE) questionnaire were administered in a general population sample of genetically related individuals (n = 755). Individuals scoring high (>75th percentile) or average on the CAPE (between 40th and 60th percentile) (n = 488) were reinterviewed with the CAPE and Structured Interview for Schizotypy-Revised (SIS-R) at follow-up (mean interval = 7.7 months, SD = 4.8 months).

RESULTS

Cross-trait, within-relative analysis showed a significant association between the CFQ and the negative dimension, assessed with both the CAPE and SIS-R, whereas no association was found between the CFQ and the positive dimension. Cross-trait, between-relative analyses showed no association between the CFQ in one relative and any of the dimensions of the subclinical psychosis phenotype in the other relative.

CONCLUSION

Proneness to subjective cognitive failure possibly contributes to the development or persistence of negative symptoms and can be seen as potential risk factor for negative symptoms of psychosis. This overlap is due to individual effects rather than familial liability.

A systematic review and meta-analysis of the psychosis continuum: evidence for a psychosis proneness-persistence-impairment model of psychotic disorder

A systematic review of all reported incidence and prevalence studies of population rates of subclinical psychotic experiences reveals a median prevalence rate of around 5% and a median incidence rate of around 3%. A meta-analysis of risk factors reveals associations with developmental stage, child and adult social adversity, psychoactive drug use, and also male sex and migrant status. The small difference between prevalence and incidence rates, together with data from follow-up studies, indicates that approximately 75-90% of developmental psychotic experiences are transitory and disappear over time. There is evidence, however, that transitory developmental expression of psychosis (psychosis proneness) may become abnormally persistent (persistence) and subsequently clinically relevant (impairment), depending on the degree of environmental risk the person is additionally exposed to. The psychosis proneness-persistence-impairment model considers genetic background factors impacting on a broadly distributed and transitory population expression of psychosis during development, poor prognosis of which, in terms of persistence and clinical need, is predicted by environmental exposure interacting with genetic risk.

Does reactivity to stress cosegregate with subclinical psychosis? A general population twin study

OBJECTIVE

This study assessed the relationship between stress reactivity (trait 1) and psychosis (trait 2) across genetically related persons (cross-twin, cross-trait design) to examine whether stress reactivity is an uncontaminated and unconfounded familial marker of psychosis risk.

METHOD

Reactivity to stress and subclinical psychotic experiences were assessed in 289 female, general population twin-pairs. Cross-trait, within-twin associations investigating the association between stress reactivity and subclinical psychotic experiences in each person, were calculated. In addition, cross-trait, cross-twin associations were calculated to assess whether stress reactivity in one twin was moderated by subclinical psychotic experiences in the co-twin.

RESULTS

Cross-trait, within-twin analyses showed significant associations between stress reactivity and subclinical psychotic experiences in each person. In addition, the cross-trait cross-twin analyses showed that stress reactivity in twin 1 was significantly moderated by subclinical experiences in the co-twin.

CONCLUSION

The results suggest that the psychosis phenotype cosegregates with increased emotional reactivity to stress in daily life.