Early prodromal symptoms can predict future psychosis in familial high-risk youth

Associations between social engagement, internalizing symptoms, and delusional ideation in the general population

BACKGROUND

Delusions are a hallmark feature of psychotic disorders and lead to significant clinical and functional impairment. Internalizing symptoms-such as symptoms of depression, anxiety, and trauma exposure-are commonly cited to be related to delusions and delusional ideation and are often associated with deficits in social functioning. While emerging studies are investigating the impact of low social engagement on psychotic-like experiences, little work has examined the relationship between social engagement, internalizing symptoms, and delusional ideation, specifically.

METHODS

Using general population data from the Nathan Kline Institute-Rockland (NKI-Rockland) database (N = 526), we examined the relationships between self-reported delusional ideation, internalizing symptoms, and social engagement and tested four indirect effect models to understand how these factors interrelate.

RESULTS

Delusional ideation was significantly associated with both increased internalizing symptoms (r = 0.41, p < 0.001) and lower social engagement (r = - 0.14, p = 0.001). Within aspects of social engagement, perceived emotional support showed the strongest relationship with delusional ideation (r = - 0.17, p < 0.001). Lower social engagement was also significantly associated with increased internalizing symptoms (r = - 0.29, p < 0.001). Cross-sectional models suggest that internalizing symptoms have a significant indirect effect on the association between delusional ideation and social engagement.

CONCLUSIONS

These findings reveal that elevated delusional ideation in the general population is associated with lower social engagement. Elevated internalizing symptoms appear to play a critical role in reducing engagement, possibly exacerbating delusional thinking. Future work should examine the causal and temporal relationships between these factors.

The relations of psychotic-like experiences (PLEs) and depressive symptoms and the bias of depressive symptoms during the clustering among Chinese adolescents: Findings from the network perspective

BACKGROUND

There are rare studies about the network structure of psychotic-like experiences (PLEs) and depressive symptoms among adolescents. Studies have widely acknowledged that PLEs in adolescents confer a higher risk of depressive symptoms, but the complex interactions remain inadequately understood. Our study aimed to examine the hierarchy and inter-associations of PLEs and depressive symptoms in a large adolescent sample from the network analysis perspective.

METHODS

A total of 5008 Chinese adolescents were enrolled in our sample. Community Assessment of Psychic Experiences-42 (CAPE-42) was applied to build the network. Centrality indexes were calculated to represent the significance of nodes in the network. Community detection was conducted to figure out the specific clustering of nodes. Demographic information was collected for the sub-network comparisons. Accuracy and stability of the network were also tested.

RESULTS

"Failure", "External control", and "Lack of activity" were the most central nodes. The main bridge nodes linking PLEs and depressive symptoms were "Failure", "Guilty", and "No future". Positive PLE "Odd looks" and negative PLE "Unable to terminate" are the two PLEs that were most relevant to depressive nodes. Community detection further demonstrated the bias of depressive nodes in the data-driven clustering. Comparative sub-network analysis suggested that age was the only demographic factor related to the current network.

CONCLUSION

In this study of a large adolescent sample, we first demonstrated the network structure and specific clustering preference of PLEs and depressive symptoms. Our findings may enhance the understanding of the relationship between PLE and depressive symptoms.

Facial emotion recognition processes according to schizotypal personality traits: An eye-tracking study

Facial emotion recognition has been shown to be impaired among patients with schizophrenia and, to a lesser extent, among individuals with high levels of schizotypal personality traits. However, aspects of gaze behavior during facial emotion recognition among the latter are still unclear. This study therefore investigated the relations between eye movements and facial emotion recognition among nonclinical individuals with schizotypal personality traits. A total of 83 nonclinical participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a facial emotion recognition task. Their gaze behavior was recorded by an eye-tracker. Self-report questionnaires measuring anxiety, depressive symptoms, and alexithymia were administered. At the behavioral level, correlation analyses showed that higher SPQ scores were associated with lower surprise recognition accuracy scores. Eye-tracking data revealed that higher SPQ scores were associated with shorter dwell time on relevant facial features during sadness recognition. Regression analyses revealed that the total SPQ score was the only significant predictor of eye movements during sadness recognition, and depressive symptoms were the only significant predictor of surprise recognition accuracy. Furthermore, dwell time predicted response times for sadness recognition in that shorter dwell time on relevant facial features was associated with longer response times. Schizotypal traits may be associated with decreased attentional engagement in relevant facial features during sadness recognition and impede participants' response times. Slower processing and altered gaze patterns during the processing of sad faces could lead to difficulties in everyday social situations in which information must be rapidly processed to enable the successful interpretation of other people's behavior.

Prevalence and risk factors of self-reported psychotic experiences among high school and college students: A systematic review, meta-analysis, and meta-regression

BACKGROUND

Adolescents are at high risk of incident psychopathology. Fleeting psychotic experiences (PEs) that emerge in young people in response to stress may be warning signs that are missed by research that fails to study stressed populations, such as late high school and college/university students. Our aim in this systematic review was to conduct a meta-analysis that estimates prevalence rates of PEs in students, and to assess whether these rates differ by gender, age, culture, and COVID-19 exposure.

METHOD

We searched nine electronic databases, from their inception until January 31, 2022 for relevant studies. We pooled the estimates using the DerSimonian-Laird technique and random-effects meta-analysis. Our main outcome was the prevalence of self-reported PEs in high school and college/university students. We subsequently analyzed our data by age, gender, population, country, culture, evaluation tool, and COVID-19 exposure.

RESULTS

Out of 486 studies retrieved, a total of 59 independent studies met inclusion criteria reporting 210' 024 students from 21 different countries. Nearly one in four students (23.31%; 95% CI 18.41%-29.05%), reported having experienced PEs (heterogeneity [Q = 22,698.23 (62), p = 0.001] τ2  = 1.4418 [1.0415-2.1391], τ = 1.2007 [1.0205-1.4626], I2  = 99.7%, H = 19.13 [18.59-19.69]). The 95% prediction intervals were 04.01%-68.85%. Subgroup analyses showed that the pooled prevalence differed significantly by population, culture, and COVID-19 exposure.

CONCLUSION

This meta-analysis revealed high prevalence rates of self-reported PEs among teen and young adult students, which may have significance for mental health screening in school settings. An important realization is that PEs may have very different mental health meaning in different cultures.

Developmental Pathways and Clinical Outcomes of Early Childhood Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder: A Prospective, Longitudinal Cohort Study - The Danish High Risk and Resilience Study, VIA 11

OBJECTIVE

Psychotic experiences are common in children and adolescents and are associated with concurrent and subsequent psychopathology. Most findings originate from general population studies, whereas little is known of the clinical outcomes of psychotic experiences in children and adolescents at familial high risk of psychosis. We examined the prevalence of psychotic experiences in middle childhood and whether early childhood psychotic experiences and developmental pathways of psychotic experiences predicted mental disorders in middle childhood in children at familial high risk of schizophrenia (FHR-SZ), bipolar disorder (FHR-BP), and a population-based control group.

METHODS

In a longitudinal population-based cohort study children at FHR-SZ (N=170), FHR-BP (N=103), and the control group (N=174) were assessed for psychotic experiences and axis I disorders with face-to-face interviews in early and middle childhood (at 7 and 11 years of age).

RESULTS

Psychotic experiences were more prevalent in children at FHR-SZ (31.8%, odds ratio 2.1, 95% CI 1.3-3.4) than in the control group (18.4%) in middle childhood. Early childhood psychotic experiences predicted mental disorders in middle childhood after adjusting for early childhood disorders and familial risk (odds ratio 2.0, 95% CI 1.2-3.1). Having three or more psychotic experiences increased odds the most (odds ratio 2.5, 95% CI 1.1-5.7). Persistent psychotic experiences were associated with increased odds of middle childhood disorders (odds ratio 4.1, 95% CI 2.1-8.4). Psychotic experiences were nondifferentially associated with mental disorders across the three familial risk groups.

CONCLUSIONS

Early childhood psychotic experiences predict mental disorders in middle childhood. Psychotic experiences index vulnerability for psychopathology nondifferentially in children at familial high risk and the control group. Psychotic experiences should be included in mental health screenings including children at familial high risk.

Family history of psychosis in youth at clinical high risk: A replication study

Having a first-degree relative with a psychotic disorder increases an individual's risk for developing psychosis to 10% compared to 1% in the general population. The impact of being at family high-risk for psychosis (FHR) has been examined in samples of youth who are at clinical high-risk for psychosis (CHR). The second North American Prodrome Longitudinal Study (NAPLS-2) identified very few clinical differences between CHR individuals with and without FHR. This paper aims to confirm these results in a new CHR sample, NAPLS-3. The NAPLS-3 sample consisted of 703 CHR participants, of whom 82 were at FHR (CHR+FHR), and 621 were not (CHR+FHRneg). The Family Interview for Genetic Studies was used to determine the presence of a first-degree relative with a psychotic disorder. The groups were compared on social and role functioning, positive and negative symptoms, IQ, cannabis use, and trauma. At baseline, the CHR+FHR group reported a statistically significant increased severity of positive and negative symptoms, lower IQ scores, and increased reports of trauma, psychological and physical abuse. There were no differences in transition rates between the two groups. This study supports some of the already reported differences in trauma, physical and psychological abuse between CHR individuals with and without FHR.

Subjective Cognitive Complaints in Unaffected First-Degree Relatives of Schizophrenia Patients: Relation to Cognitive Performance, Psychotic Experiences, and Social Functioning

Background

Neurocognitive deficits are well-documented in patients of schizophrenia and their first-degree relatives (FDRs). Metacognitive awareness of these deficits, called neurocognitive insight (NI), has been found to be poor in schizophrenia patients but has not been assessed in their FDRs. This study evaluated NI and its relationship with objective cognitive performance, a history of psychotic experiences (PEs), and social functioning in unaffected FDRs.

Methods

This cross-sectional study was conducted at the outpatient department of a tertiary care teaching hospital. A total of 100 FDRs were assessed for PEs and evaluated for subjective cognitive complaints (SCC), objective cognitive performance, and social functioning using the Subjective Scale to Investigate Cognition in Schizophrenia, neurocognitive tests from the National Institute of Mental Health and Neurosciences battery, and SCARF Social Functioning Index, respectively.

Results

Compared to normative data, episodic memory was the most commonly impaired domain (up to 72% of participants), followed by working memory, attention, and executive function. There was no correlation between SCC and neuropsychological test scores in the corresponding cognitive domains, implying poor NI. 15% of participants had a lifetime history of PEs. This group had significantly higher SCC as compared to those without PEs (U = 0.366, P = 0.009, r = 0.26). A regression analysis showed that the FDRs' social functioning reduced by 0.178 units for each unit increase in SCC [F (1,98) = 5.198, P = 0.025].

Conclusion

Similar to schizophrenia patients, FDRs also have poor NI. The severity and progression of SCC could be explored as a possible marker for screening and monitoring FDRs at an ultrahigh risk for psychosis. Importantly, even in unaffected FDRs, SCC could affect socio-occupational functioning and need further research.

Biomarker Profiles in Psychosis Risk Groups Within Unaffected Relatives Based on Familiality and Age

Investigating biomarkers in unaffected relatives (UR) of individuals with psychotic disorders has already proven productive in research on psychosis neurobiology. However, there is considerable heterogeneity among UR based on features linked to psychosis vulnerability. Here, using the Bipolar-Schizophrenia Network for Intermediate Phenotypes (B-SNIP) dataset, we examined cognitive and neurophysiologic biomarkers in first-degree UR of psychosis probands, stratified by 2 widely used risk factors: familiality status of the respective proband (the presence or absence of a first- or second-degree relative with a history of psychotic disorder) and age (within or older than the common age range for developing psychosis). We investigated biomarkers that best differentiate the above specific risk subgroups. Additionally, we examined the relationship of biomarkers with Polygenic Risk Scores for Schizophrenia (PRSSCZ) in a subsample of Caucasian probands and healthy controls (HC). Our results demonstrate that the Brief Assessment of Cognition in Schizophrenia (BACS) score, antisaccade error (ASE) factor, and stop-signal task (SST) factor best differentiate UR (n = 169) from HC (n = 137) (P = .013). Biomarker profiles of UR of familial (n = 82) and non-familial (n = 83) probands were not significantly different. Furthermore, ASE and SST factors best differentiated younger UR (age ≤ 30) (n = 59) from older UR (n = 110) and HC from both age groups (age ≤ 30 years, n=49; age > 30 years, n = 88) (P < .001). In addition, BACS (r = -0.175, P = .006) and ASE factor (r = 0.188, P = .006) showed associations with PRSSCZ. Taken together, our findings indicate that cognitive biomarkers-"top-down inhibition" impairments in particular-may be of critical importance as indicators of psychosis vulnerability.

A multivariate analysis of the association between corticostriatal functional connectivity and psychosis-like experiences in the general community

Dysfunction of dorsal corticostriatal (CST) circuitry is thought to play an important role in psychosis. Here, we use multivariate analysis to characterize covariance between CST functional connectivity and psychosis-like experiences (PLEs) in non-clinical individuals. In 353 healthy adults (155 males), we use partial least squares (PLS) to identify latent variables (LV) describing covariance between seven PLE questionnaire measures and functional connectivity estimated between each of six striatal seed regions and the rest of the brain using multiband resting-state fMRI. Hypothesis-driven PLS of the dorsal caudate (DC) seed identified one significant LV, accounting for 23.88% of covariance, with loadings from nearly all PLE subscales. Cortical regions implicated in this LV comprise anterior cingulate and left dorsolateral prefrontal cortex. Lower connectivity between these cortical areas and the DC seed was associated with more severe PLEs. Using multivariate modeling, we identified an association between dorsal CST connectivity and PLEs in the general community that implicates similar brain regions to those identified in patient groups. Our results highlight that the severity of both positive/negative symptom-like PLEs is related with functional coupling between the DC and dorsolateral PFC, suggesting this neural circuit may play a role in mediating risk for general psychosis-related psychopathology.

Psychotic-Like Experiences: A Challenge in Definition and Assessment

Assuming a continuum between psychotic experiences and psychotic symptoms aligned between healthy individuals and patients with non-psychotic and psychotic disorders, recent research has focused on subclinical psychotic experiences. The wide variety of definitions, assessment tools, and concepts of psychotic-like experiences (PLEs) might contribute to the mixed findings concerning prevalence and persistence rates and clinical impact. In this narrative review, we address the panoply of terminology, definitions, and assessment tools of PLEs and associated concerns with this multitude. Moreover, the ambiguous results of previous studies regarding the clinical relevance of PLEs are described. In conclusion, we address clinical implications and highly suggest conceptual clarity and consensus concerning the terminology and definition of PLEs. The development of an agreed upon use of a "gold standard" assessment tool seems essential for more comparable findings in future research.

Lifetime psychopathology in child and adolescent offspring of parents diagnosed with schizophrenia or bipolar disorder: a 2-year follow-up study

Having one parent diagnosed with a severe mental disorder is considered one of the main risk factors for developing that disorder in adulthood, and it also increases the risk of a wide range of mental disorders in the offspring. The aim of this study is to compare the prevalence of several psychopathological diagnoses, the presence of prodromal symptoms, and global functioning in offspring of parents with schizophrenia or bipolar disorder and in offspring of controls at baseline and 2-year follow-up. This study included 41 offspring of parents with schizophrenia, 90 offspring of parents with bipolar disorder, and 107 offspring of controls (mean age 11.7 ± 3.2 at baseline and 13.9 ± 3.2 at follow-up). The prevalence of psychopathology and comorbidity was higher in offspring of parents with schizophrenia and offspring of parents with bipolar disorder than in offspring of controls at baseline and at 2-year follow-up. Interestingly, mood disorders were more prevalent in offspring of parents with bipolar disorder and disruptive disorders were more prevalent in offspring of parents with schizophrenia. Prodromal symptoms were more frequent in offspring of parents with schizophrenia than in offspring of controls, while the offspring of parents with bipolar disorder showed an intermediate pattern. Finally, global functioning was lower in the offspring of parents with schizophrenia than the offspring of parents with bipolar disorder and the offspring of controls. Screening patients' children is clinically relevant, since, as a group, they have an elevated risk of developing a psychiatric disorder and of experiencing their first symptoms during childhood and adolescence.

Prevalence and Correlates of Psychotic Like Experiences in a Large Community Sample of Young Adults in Tunisia

Despite the increased focus on non-clinical psychosis populations, no community surveys have properly investigated the phenotypal expression of Psychotic like experiences (PLEs) in the Arab-Muslim world. We aimed to examine the prevalence and correlates of PLEs in a large sample of Tunisian college students. A total of 1489 students (64.3% female, aged 18-40) participated in a cross-sectional survey. The Positive Subscale of Community Assessment of Psychotic Experiences was used to measure PLEs. The rates of PLEs found in our work were relatively high compared with those found in previous international studies, with 51.4% of the participants reporting at least one positive PLE 'nearly-always'. After controling for confounding variables, other drug use in the past year represented the only substance use variable among the significant predictors in the final model. Our findings should raise awareness of the need for implementing an early intervention programs in our region.

Abnormal Bodily Phenomena in First Episode Psychosis: A Preliminary Exploratory Cohort Study

Schizophrenia patients frequently display an array of abnormal bodily phenomena (ABPs). There is literature to suggest that the presence of ABPs may be representative of a fundamental disruption of the embodied and prereflexive state of selfhood and hence be relevant for the development of schizophrenia spectrum disorders. ABPs have been considered as trait features of vulnerability to psychosis and may have value as potential markers for early detection, target symptoms for prevention and predictors of clinical outcomes. This longitudinal cohort study aimed to explore: (1) the prevalence of ABPs in first episode psychosis, (2) their longitudinal stability, (3) how ABPs compare with data from patients with enduring psychosis, and (4) how aspects of disorders of self-experience (DSEs) and ABPs and the corresponding instruments relate to each other. Sixteen patients were recruited from an early intervention in psychosis service. They were assessed with a series of structured and semi-structured interviews at point of entry, after 6 months and 12 months of follow-up. A variety of ABPs and DSEs were displayed in all study subjects, associated with high levels of core psychotic symptoms and reduced with treatment over time. Compared with findings of both acute and chronic schizophrenia patients, the prevalence of ABPs seems to be representative of severity and acuteness of the illness. Two factors were identified with stable trait characteristics and might be of predictive value for the course of the illness. Further studies with bigger samples are needed to further test the value of ABPs as early markers of detection and predictors of clinical course. The association between DSEs and ABPs warrants further investigation.

Characterization of children and adolescents with psychosis risk syndrome: The Children and Adolescents Psychosis Risk Syndrome (CAPRIS) study

AIM

Despite the interest in psychosis risk syndrome (PRS) in children and adolescents, information on the syndrome in this population is scarce.

METHODS

Prospective naturalistic multi-site study in which 10- to 17-year-old help-seeking subjects who met PRS criteria (positive or negative attenuated symptoms; brief limited intermittent psychotic symptoms; genetic risk or schizotypal personality disorder plus impairment in functioning) were included, along with 45 age and sex-matched healthy controls (HC). All subjects were clinically and functionally assessed.

RESULTS

Ninety-one PRS subjects (PRSS) with a mean age of 15.5 ± 1.4 met inclusion criteria (IC). Compared with HC, PRSS presented worse global and academic functioning in the previous year, had experienced more psychiatric and psychological problems, and presented gestational ages outside the normal range. More than 80% of PRSS met ≥2 IC, with 65.9% having one Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision diagnosis, and 61.7% of those having ≥2 diagnoses. Some 49.5% of PRSS had a first- or second-degree family history (FH) of psychosis. Patients with first- and second-degree FH do not differ in their clinical expression.

CONCLUSIONS

Children and adolescents with PRS are a patient group with a pattern of neurodevelopmental impairment and clinical complexity similar to patients with schizophrenia spectrum disorders, highlighting the importance of assessing these variables in child and adolescent samples. PRSS with first- and second-degree relatives with FH do not present differences in their clinical presentation, suggesting that including these two groups of patients in the genetic risk criteria would enrich knowledge of these criteria.

Does hallucination perceptual modality impact psychosis risk?

OBJECTIVE

Subthreshold perceptual abnormalities are commonly used to identify individuals at clinical high risk (CHR) for developing a psychotic disorder. Predictive validity for modality-specific perceptual abnormality severity on psychosis risk is unknown.

METHODS

We examined prospectively collected data from 164 individuals age 12-35 meeting criteria for CHR followed for 6-24 months or until conversion to psychosis. Using intake interview notes, baseline perceptual abnormality scores were split into auditory, visual, somatic/tactile, and olfactory/gustatory components, and auditory scores were further split into those for verbal vs non-verbal content. Relationships between perceptual abnormality characteristics and conversion were assessed with Cox proportional hazards regression and logistic regression.

RESULTS

Unusual thought content and paranoia were predictive of conversion, but no modality-specific perceptual abnormality score predicted conversion status or days to conversion. However, when auditory perceptual abnormalities were further categorized as verbal vs non-verbal, the severity of verbal experiences was predictive of conversion to psychosis (P = 0.007).

CONCLUSIONS

Perceptual abnormality scores failed to meaningfully predict conversion to psychosis in either direction in this CHR sample. However, verbal auditory experiences may identify a group of CHR individuals at elevated risk of conversion. Further exploration of the relationship between phenomenological aspects of perceptual abnormalities and conversion risk is warranted.

The interrelationship between schizotypy, clinical high risk for psychosis and related symptoms: Cognitive disturbances matter

Schizotypy and clinical high risk (CHR) criteria can identify individuals who are at increased risk for developing psychosis in community and patient samples. However, both approaches have rarely been combined, and very little is known about their associations. Therefore, we examined the factorial structure of CHR and related symptoms and schizotypy features as well as their interrelationship for the first time in a comprehensive approach. In a sample of 277 patients (22 ± 6 years) from two early detection services, structural equation modeling including confirmatory factor analysis was performed to test a theory-driven model using four Wisconsin Schizotypy Scales, 14 predictive basic symptoms (BS) of the Schizophrenia Proneness Instrument, and positive, negative, and disorganized symptoms from the Structured Interview for Psychosis-Risk Syndromes. The data fitted well to the six hypothesized latent factors consisting of negative schizotypy, positive schizotypy including perceptual BS, negative symptoms, positive symptoms, disorganized symptoms and cognitive disturbances. As postulated, schizotypy features were significantly associated with positive, negative and disorganized symptoms through cognitive disturbances. Additionally, positive and negative schizotypy also had a direct association with the respective symptom-domain. While the identified factorial structure corresponds well to dimensional models of schizotypy and psychoses, our model extends earlier models by indicating that schizotypy features are associated with positive, negative and disorganized symptoms directly or indirectly via subjective cognitive disturbances. This calls for more attention to subjective cognitive deficits in combination with heightened schizotypy in the early detection and intervention of psychoses - or even of an Attenuated Psychosis Syndrome.

Clinical psychopathology in youth at familial high risk for psychosis

AIM

While the course of psychopathology has been explored from an index mental health diagnosis onwards, there are few detailed, prospective studies of the occurrence of clinical psychopathology in youth with familial risk for severe mental illnesses such as psychosis. We sought to describe the appearance of Axis I psychopathology in a unique sample of adolescents with a family history of schizophrenia (FHR).

METHODS

One hundred and sixty two first- and second-degree relatives (mean age 15.7 ± 3.6; range 8-25) of probands with schizophrenia or schizoaffective disorder were assessed at baseline and annual intervals for up to 3 years, focusing on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) Axis I psychopathology.

RESULTS

Fourteen individuals (8.6%) developed a psychotic disorder. One hundred and five subjects (65%) met criteria for an Axis I disorder over the course of the study, the most common of which was a depressive episode (40 subjects; 25%). Of the 148 individuals who did not develop psychosis, 91 (61%) had one or more Axis I disorders compared with 10/14 converters who had a comorbid Axis I disorder (71%). Ordered by increasing age of onset, diagnoses included cognitive and externalizing disorders, anxiety disorders, affective disorders, substance use disorders and psychotic disorders.

CONCLUSIONS

In addition to an elevated risk of psychosis, young FHR relatives manifest a broad range of non-psychotic Axis I psychopathology in childhood and adolescence. This breadth of diagnoses has implications for the structure and function of mental health services for young people.

The role of a family history of psychosis for youth at clinical high risk of psychosis

AIM

On average, there is a 10% to 12% likelihood of developing a psychotic disorder solely based on being at familial high risk. However, the introduction of the criteria for clinical high risk (CHR) of psychosis suggested for CHR individuals, 20% to 30% will go on to develop a full-blown psychotic illness within 3 years. Several studies suggest a role for family history in conversion to psychosis among those at CHR. However, we know very little about those who meet the CHR criteria and have a positive family history for psychosis compared to those at CHR with no known family history. The aim of this study was to compare these 2 groups on demographics, clinical symptoms, social and role functioning, IQ, environmental factors and conversion to psychosis.

METHOD

A total of 762 participants met criteria for being at CHR, 119 of whom had a family history (CHR + FH) and 643 without (CHR-FH). Groups were compared on attenuated symptoms, role and social functioning, IQ, past trauma, perceived discrimination and cannabis use. Survival analysis was used to compare groups on conversion rates.

RESULTS

There were no major differences between the groups in symptoms, functioning, IQ, cannabis use or in the rate of conversion between the groups. The CHR + FH group reported increased amounts of early trauma.

CONCLUSION

There is a possibility that CHR + FH individuals believe that it is more difficult for them to cope with circumstances such as abuse or potential abuse. Future research on this subject should investigate family environment and its role in conversion to psychosis among CHR + FH individuals.

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

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

The Network Structure of Schizotypal Personality Traits

Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.

Psychosis Risk Syndrome: What Now?

BACKGROUND

Schizophrenia is a chronic psychiatric disorder that generally begins in late adolescence or early adulthood. This early onset is often linked with a devastating lifelong impact on both the social network and work capacities of the affected subjects. Beginning in the mid-1990s, several sets of diagnostic criteria aiming to identify "high-risk" patients were developed and applied in clinical studies. Short-term rates of onset of psychosis in this subgroup of subjects ranged from 20% to 40%. However, 20 years later, the proposal to introduce "psychosis risk syndrome" as a coded diagnostic category in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders remained controversial and was finally rejected. Instead, "attenuated psychosis syndrome" was included in section III of the newly published manual as a condition for further studies.

OBJECTIVE

The goal of this article is to review the extant literature concerning the advantages and risks of early assessment of psychotic symptoms ("prodrome" and "psychosis-risk syndrome") and concerning available therapeutic options, both psychosocial and pharmacological.

CONCLUSIONS

"Attenuated psychosis syndrome" is a clinically useful concept. It identifies help-seeking individuals with mental health problems who need an intervention and who, if no treatment strategy is proposed, present a higher likelihood of developing a psychosis spectrum disorder in the years following their first contact with a mental health facility. In parallel with the clinical utility of this concept, additional research focused on this group of patients is warranted to further understand the emerging phase of psychotic disorders and to develop effective and efficient evidence-based prevention strategies.

Subcortical surface shape in youth at familial high risk for schizophrenia

Abnormalities in the subcortical brain regions that support cognitive functions have been reported in schizophrenia. Relatives of those with schizophrenia often present with psychosis-like traits (schizotypy) and similar cognition as those with schizophrenia. To evaluate the relationships between subcortical structure, schizotypy, and cognitive function, we assessed shape and volume of the hippocampus, amygdala and thalamus in untreated youth at familial high risk for schizophrenia (HRSZ). The sample consisted of 66 HRSZ and 69 age-matched healthy controls (HC). Subjects' cognitive functions and schizotypy were assessed, and T1-weighted brain MRI were analyzed using the FSL software FIRST. The right hippocampus and right amygdala showed significantly increased concavity (inward displacement) in HRSZ compared to HC. While regional subcortical shape displacements were significantly correlated with sustained attention and executive function scores in HC, fewer correlations were seen in HRSZ. This suggests a possible alteration of the local structure-function relationship in subcortical brain regions of HRSZ for these cognitive domains, which could be related to anomalous plasticity.

Psychotic-Like Experiences at the Healthy End of the Psychosis Continuum

There is increasing evidence pointing toward a continuous distribution of psychotic symptoms and accompanying factors between subclinical and clinical populations. However, for the construction of continuum models, a more detailed knowledge of different types of psychotic-like experiences (PLE) and their associations with distress, functional impairment, and demographic variables is needed. We investigated PLE in a sample of healthy adults (N = 206) incorporating the recently developed revised Exceptional Experiences Questionnaire (PAGE-R). For the first time, the PAGE-R was cross validated with PLE, disorganized-, and negative-like symptoms [Schizotypal Personality Questionnaire (SPQ), Physical Anhedonia Scale (PAS)]. We subjected the PAGE-R to exploratory factor analyses and examined the resulting subtypes of EE for specific associations with contextual factors, valence ratings, socio-demographic variables, and general psychological burden (Revised Symptom-Checklist-90). Correlational cross-validation suggested that the PAGE-R measures facets of PLE. Importantly, we (1) identified three types of exceptional experiences (EE): Odd beliefs, dissociative anomalous perceptions, and hallucinatory anomalous perceptions. Further, the results suggested that even in healthy individuals (2) PLE and EE are indicative of reduced functioning, as reflected by increased psychological burden and lower educational achievement. Moreover, (3) similar sex-differences might exist as in psychotic patients with women reporting more positive-like symptoms and EE but less disorganized-like symptoms than men. Importantly, (4) EE might be differentially implicated in psychological functioning. We suggest that the PAGE-R holds the potential to complement the current assessment of sub-clinical psychosis. However, whereas our results might point toward a continuity of psychotic symptoms with EE and normal experiences, they require replication in larger samples as well as equivalence testing across the psychosis continuum. Future analyses incorporating the PAGE-R might shed more light onto mechanisms that are implicated in the progress or resilience toward clinical illness.

The "polyenviromic risk score": Aggregating environmental risk factors predicts conversion to psychosis in familial high-risk subjects

BACKGROUND

Young relatives of individuals with schizophrenia (i.e. youth at familial high-risk, FHR) are at increased risk of developing psychotic disorders, and show higher rates of psychiatric symptoms, cognitive and neurobiological abnormalities than non-relatives. It is not known whether overall exposure to environmental risk factors increases risk of conversion to psychosis in FHR subjects.

METHODS

Subjects consisted of a pilot longitudinal sample of 83 young FHR subjects. As a proof of principle, we examined whether an aggregate score of exposure to environmental risk factors, which we term a 'polyenviromic risk score' (PERS), could predict conversion to psychosis. The PERS combines known environmental risk factors including cannabis use, urbanicity, season of birth, paternal age, obstetric and perinatal complications, and various types of childhood adversity, each weighted by its odds ratio for association with psychosis in the literature.

RESULTS

A higher PERS was significantly associated with conversion to psychosis in young, familial high-risk subjects (OR=1.97, p=0.009). A model combining the PERS and clinical predictors had a sensitivity of 27% and specificity of 96%.

CONCLUSION

An aggregate index of environmental risk may help predict conversion to psychosis in FHR subjects.

Pituitary volume and clinical trajectory in young relatives at risk for schizophrenia

BACKGROUND

Stress and vulnerability likely interact to play a major role in psychosis. While much has been written about the neural diathesis-stress model in psychosis and its clinical risk states, little is known about HPA axis biomarkers in non-help-seeking individuals at familial high risk (FHR). We sought to prospectively measure pituitary volume (PV) in adolescents and young adults at FHR for schizophrenia and to follow their emerging sub-clinical psychotic symptoms and clinical trajectories.

METHOD

Forty healthy controls and 38 relatives of patients with schizophrenia or schizoaffective disorder were identified in Pittsburgh, USA. PV was derived from baseline 1.5 T magnetic resonance imaging. Chapman's schizotypy scales were acquired at baseline, and structured clinical interviews for DSM-IV-TR Axis I diagnoses were attempted annually for up to 3 years.

RESULTS

Seven individuals converted to psychosis. PV did not differ between FHR and control groups overall. Within the FHR group, PV was positively correlated with Chapman's positive schizotypy (Magical Ideation and Perceptual Aberration) scores, and there was a significant group × PV interaction with schizotypy. PV was significantly higher in FHR subjects carrying any baseline Axis I diagnosis (p = 0.004), and higher still in individuals who went on to convert to psychosis (p = 0.0007).

CONCLUSIONS

Increased PV is a correlate of early positive schizotypy, and may predict trait vulnerability to subsequent psychosis in FHR relatives. These preliminary findings support a model of stress-vulnerability and HPA axis activation in the early phases of psychosis.

Screening schizotypal personality disorder for detection of clinical high risk of psychosis in Chinese mental health services

Schizotypal personality disorder (SPD) is viewed as a marker of prodromal psychosis. However, information regarding genetic risk (e.g. SPD) is often overlooked in the identification process. This study assessed whether SPD screening questionnaire help the prodromal psychosis (also widely applied "clinical high risk" (CHR) for clinical sample) detection in Chinese mental health service. This work also examined whether SPD had higher frequency in genetic risk population and CHR subjects. Two wave studies concerning the SPD identification was used for analysis. Wave 1 survey: 3075 subjects were assessed by Personality Diagnostic Questionnaire for SPD (PDQ-SPD) and Structured Clinical Interview for DSM-IV Axis II (SCID-II). Wave 2 survey: 2113 subjects screened with the prodromal questionnaire -brief version (PQ-B), PDQ-SPD, and interviewed by Structured Interview for Prodromal Symptoms (SIPS). Subjects with family history of mental disorders or with psychosis reported significantly higher scores in SPD. Receiver operating characteristic curves suggested that PDQ-SPD had moderate sensitivity and specificity for identifying CHR subjects. There was significant higher on SPD features in subjects with early stage (Course less than 1 year) of psychosis. Identifying SPD may be useful in early detection of psychosis especially in detecting the genetic risk syndromes and can be integrated with existing prodromal screen tools to improve its efficiency.

Predicting psychosis in a general adolescent psychiatric sample

INTRODUCTION

Current psychosis risk criteria have often been studied on a pre-selected population at specialized clinics. We investigated whether the Structured Interview for Prodromal Syndromes (SIPS) is a useful tool for psychosis risk screening among adolescents in general psychiatric care.

METHODS

161 adolescents aged 15-18 with first admission to adolescent psychiatric services in Helsinki were interviewed with the SIPS to ascertain Clinical High-Risk (CHR) state. The participants were followed via the national hospital discharge register, patient files, and follow-up interviews. DSM-IV Axis I diagnoses were made at baseline and 12 months. Register follow-up spanned 2.8-8.9 years, and hospital care for a primary psychotic disorder and any psychiatric disorder were used as outcomes.

RESULTS

CHR criteria were met by 54 (33.5%) of the adolescents. Three conversions of psychosis as defined by SIPS emerged during follow-up, two of whom belonged to the CHR group. The positive predictive value of the CHR status was weak (1.9%) but its negative predictive value was 98.0%. Using the DSM-IV definition of psychosis, there were five conversions, three of which were in the CHR group. In regression analyses, hospital admissions for primary psychotic disorder were predicted by positive symptom intensity in the baseline SIPS. In addition, CHR status and SIPS positive and general symptoms predicted hospitalization for psychiatric disorder.

DISCUSSION

Psychosis incidence was low in our unselected sample of adolescent psychiatric patients. CHR status failed to predict SIPS or DSM-IV psychoses significantly at 12 months. However, in a longer follow-up, CHR did predict psychiatric hospitalization.

Correspondence between psychometric and clinical high risk for psychosis in an undergraduate population

Despite the common use of either psychometric or clinical methods for identifying individuals at risk for psychosis, previous research has not examined the correspondence and extent of convergence of these 2 approaches. Undergraduates (n = 160), selected from a larger pool, completed 3 self-report schizotypy scales: the Magical Ideation Scale, the Perceptual Aberration Scale, and the Revised Social Anhedonia Scale. They were administered the Structured Interview for Prodromal Syndromes. First, high correlations were observed for self-report and interview-rated psychotic-like experiences (rs between .48 and .61, p < .001). Second, 77% of individuals who identified as having a risk for psychosis with the self-report measures reported at least 1 clinically meaningful psychotic-like experience on the Structured Interview for Prodromal Syndromes. Third, receiver operating characteristic curve analyses showed that the self-report scales can be used to identify which participants report clinically meaningful positive symptoms. These results suggest that mostly White undergraduate participants who identify as at risk with the psychometric schizotypy approach report clinically meaningful psychotic-like experiences in an interview format and that the schizotypy scales are moderately to strongly correlated with interview-rated psychotic-like experiences. The results of the current research provide a baseline for comparing research between these 2 approaches.

Epigenetics, stress, and their potential impact on brain network function: a focus on the schizophrenia diatheses

The recent sociodevelopmental cognitive model of schizophrenia/psychosis is a highly influential and compelling compendium of research findings. Here, we present logical extensions to this model incorporating ideas drawn from epigenetic mediation of psychiatric disease, and the plausible effects of epigenetics on the emergence of brain network function and dysfunction in adolescence. We discuss how gene-environment interactions, effected by epigenetic mechanisms, might in particular mediate the stress response (itself heavily implicated in the emergence of schizophrenia). Next, we discuss the plausible relevance of this framework for adolescent genetic risk populations, a risk group characterized by vexing and difficult-to-explain heterogeneity. We then discuss how exploring relationships between epigenetics and brain network dysfunction (a strongly validated finding in risk populations) can enhance understanding of the relationship between stress, epigenetics, and functional neurobiology, and the relevance of this relationship for the eventual emergence of schizophrenia/psychosis. We suggest that these considerations can expand the impact of models such as the sociodevelopmental cognitive model, increasing their explanatory reach. Ultimately, integration of these lines of research may enhance efforts of early identification, intervention, and treatment in adolescents at-risk for schizophrenia.

Psychosis prediction and clinical utility in familial high-risk studies: selective review, synthesis, and implications for early detection and intervention

AIM

Accurate prediction of which high-risk individuals will go on to develop psychosis would assist early intervention and prevention paradigms. We sought to review investigations of prospective psychosis prediction based on markers and variables examined in longitudinal familial high-risk (FHR) studies.

METHODS

We performed literature searches in MedLine, PubMed and PsycINFO for articles assessing performance characteristics of predictive clinical tests in FHR studies of psychosis. Studies were included if they reported on one or more predictive variables in subjects at FHR for psychosis. We complemented this search strategy with references drawn from articles, reviews, book chapters and monographs.

RESULTS

Across generations of FHR projects, predictive studies have investigated behavioural, cognitive, psychometric, clinical, neuroimaging and other markers. Recent analyses have incorporated multivariate and multi-domain approaches to risk ascertainment, with generally modest results.

CONCLUSIONS

Although a broad range of risk factors has been identified, no individual marker or combination of markers can at this time enable accurate prospective prediction of emerging psychosis for individuals at FHR. We outline the complex and multi-level nature of psychotic illness, the myriad of factors influencing its development, and methodological hurdles to accurate and reliable prediction. Prospects and challenges for future generations of FHR studies are discussed in the context of early detection and intervention strategies.

Brain metabolite alterations in young adults at familial high risk for schizophrenia using proton magnetic resonance spectroscopy

BACKGROUND

Proton magnetic resonance spectroscopy ((1)H MRS) enables in-vivo measurement of several relevant brain metabolites and has provided evidence of a range of neurochemical abnormalities in schizophrenia, especially in glutamate and N-acetyl-aspartate (NAA). While individuals at high familial risk for schizophrenia (HR) exhibit some neurobiological findings observed in the disorder, (1)H MRS findings and their clinical correlates are not well characterized in this population.

METHODS

We compared 23 adolescent and young adult offspring of schizophrenia patients with 24 age- and sex-matched healthy controls using (1)H MRS. We acquired multi-voxel, short TE (1)H MRS measurements at 1.5T and obtained metabolite concentrations of N-acetyl-aspartate (NAA), combined glutamate and glutamine (Glu+Gln) and choline-containing compounds (GPC+PC) for the left and right thalamus, anterior cingulate gyrus, and caudate. We also assessed the relationship between regional metabolite levels, clinical measures and brain volume in a subset of 16 high-risk and 15 control subjects.

RESULTS

Compared to healthy controls, high-risk subjects showed reductions in NAA levels in all three regions (thalamus, caudate, and anterior cingulate cortex), increases in Glu+Gln in the thalamus and caudate, and increases in GPC+PC in the anterior cingulate. In HR, thalamic Glu+Gln concentration was positively correlated and thalamic NAA inversely correlated with measures of schizotypy. Anterior cingulate GPC+PC and caudate Glu+Gln were significantly correlated with attenuated psychotic symptom severity. Anterior cingulate NAA was correlated with executive function.

CONCLUSIONS

Our data suggest the occurrence of metabolic alterations in young relatives of schizophrenia patients similar to those seen in patients with established illness. The observed correlations with cognitive deficits and psychosis-related psychopathology suggest that these metabolic measures may have value as biomarkers of risk for schizophrenia.

Schizotypal traits are associated with poorer identification of emotions from dynamic stimuli

Recent research suggests that the emotion recognition difficulties seen in schizophrenia may also be present to a lesser degree in non-clinical individuals who report attenuated expressions of schizophrenia-like symptoms (schizotypy). However, evidence in non-clinical samples primarily comes from studies employing static facial emotion tasks, and it is not clear whether poorer emotion recognition in schizotypy persists when people have access to a broader range of emotional cues more representative of typical face-to-face social interactions. A community sample of 151 adults completed measures of schizotypal traits, IQ, and a task that assessed emotion recognition using dynamic video-based stimuli. Global schizotypy and positive schizotypal traits were each associated with poorer emotion recognition. Negative schizotypy was not associated with emotion recognition overall, but was associated with errors in recognising positive emotions. It appears that poorer emotion recognition in schizotypy is not limited to single-channel stimuli, but can be seen even when multiple emotional cues are available. Thus, individuals with high levels of schizotypal traits, and positive features in particular, may have greater difficulty when it comes to 'reading' the emotions of others in everyday social interactions.

Conceptual issues in the classification of psychosis

PURPOSE OF REVIEW

To provide an update on the conceptual status of attenuated psychosis syndrome (APS) as a psychiatric disorder.

RECENT FINDINGS

In May 2012, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) Task Force announced that the planned introduction of APS as a new diagnosis in DSM-5 was cancelled and that APS was being moved to 'Section III' of the manual as a diagnostic construct requiring more work. Recent studies of APS have reflected this uncertainty and debate over its validity.

SUMMARY

Before and after the decision in May 2012 to remove APS as a new diagnosis in DSM-5, scientific work has proceeded in a robust manner to shore up the validity of APS as a diagnostic construct. Recent work on APS has revolved around a series of unresolved questions: the actual incidence of conversion of APS to full-blown psychosis, the identification of the subgroup that will convert, the appropriate treatment for APS, the ability of treatment to prevent conversion to psychosis, the wide range of long-term outcomes of APS and finally the decision whether to include APS as a formal psychiatric diagnosis. Although the debate continues, a substantial number of the major researchers have argued that APS does not yet enjoy a degree of validity that warrants inclusion as a formal diagnosis.

Facial affect recognition and schizotypal personality characteristics

AIM

Deficits in facial affect recognition are well established in schizophrenia, yet relatively little research has examined facial affect recognition in hypothetically psychosis-prone or 'schizotypal' individuals. Those studies that have examined social cognition in psychosis-prone individuals have paid little attention to the association between facial emotion recognition and particular schizotypal personality features. The present study therefore sought to investigate relationships between facial emotion recognition and the different aspects of schizotypy.

METHODS

Facial affect recognition accuracy was examined in 50 psychiatrically healthy individuals assessed for level of schizotypy using the Schizotypal Personality Questionnaire. This instrument provides a multidimensional measure of schizophrenia proneness, encompassing 'cognitive-perceptual', 'interpersonal' and 'disorganized' features of schizotypy. It was hypothesized that the cognitive-perceptual and interpersonal aspects of schizotypy would be associated with difficulties identifying facial expressions of emotion during a forced-choice recognition task using a standardized series of colour photographs.

RESULTS

As predicted, interpersonal aspects of schizotypy (particularly social anxiety) were associated with reduced accuracy on the facial affect recognition task, but there was no association between affect recognition accuracy and cognitive-perceptual features of schizotypy.

CONCLUSIONS

These results suggest that subtle deficits in facial affect recognition in otherwise psychiatrically healthy individuals may be related to the vulnerability for interpersonal communication difficulties, as seen in schizophrenia.

Multivariate prediction of emerging psychosis in adolescents at high risk for schizophrenia

BACKGROUND

Accurate prediction of psychosis development in high-risk populations is an important but thus far elusive goal. Of the many diverse etiologic and risk factors identified thus far, few have been combined into prospective multivariate risk ascertainment models. We tested the predictive power of familial, neurobiological, socioenvironmental, cognitive and clinical risk factors through an integrative biopsychosocial model for emerging psychosis in young relatives at familial risk for schizophrenia.

METHODS

96 young first- and second- degree relatives of schizophrenia probands were followed for an average of 2.38 (SD=0.98) years to examine their trajectory towards psychosis. Iterative structural equation modelling utilizing multiple etiologic and risk factors was employed to estimate their joint contribution to prediction of psychosis development.

RESULTS

The rate of conversion to psychosis over the study period was 12.5%. In the final model, clinical measures of schizotypy were directly predictive of conversion, with early (familial, biological, socioenvironmental) and cognitive risk factors indirectly predictive of psychosis through increased baseline clinical symptomatology. Our model provided an excellent fit to the observed data, with sensitivity of 0.17, specificity of 0.99, positive predictive value of 0.67 and negative predictive value of 0.89.

CONCLUSIONS

Integrative modeling of multivariate data from familial, neurobiological, socioenvironmental, cognitive and clinical domains represents a powerful approach to prediction of psychosis development. The high specificity and low sensitivity found using a combination of such variables suggests that their utility may be in confirmatory testing among already selected high-risk individuals, rather than for initial screening. These findings also highlight the importance of data from a broad array of etiologic and risk factors, even within a familial high-risk population. With further refinement and validation, such methods could form key components of early detection, intervention and prevention programs.

Sex differences in sub-clinical psychosis--results from a community study over 30 years

Sex differences in schizophrenia have long been reported. They are found within almost all aspects of the disease, from incidence and prevalence, age of onset, symptomatology, and course to its psycho-social outcome. Many sex-related hypotheses have been developed about the biology, psychology, or sociology of that disease. A further approach to study sex differences would be to examine such differences in sub-clinical psychotic states as well. If factors related to full-blown psychosis were equally meaningful over the entire psychosis continuum, we should expect that "true" sex differences could also be identified in sub-clinical psychosis. Here, we studied sex differences in sub-clinical psychosis within a community cohort in Zurich, Switzerland. This population was followed for over 30 years and included males and females between the ages of 20/21 and 49/50. We applied two different measures of sub-clinical psychosis representing schizotypal signs and schizophrenia nuclear symptoms. Using cross-sectional and longitudinal analyses, we found no significant sex differences in sub-clinical psychosis over time with respect to age of onset, symptomatology, course, or psycho-social outcome. Thus it appears that sex differences in psychosis manifest themselves at the high end of the continuum (full-blown schizophrenia) rather than within the sub-threshold range. Possibly males and females have separate thresholds for certain symptoms because they are differently vulnerable or exposed to various risk factors.

Attenuated psychosis and the schizophrenia prodrome: current status of risk identification and psychosis prevention

Recent efforts in the prevention of schizophrenia have focused on defining psychosis-risk syndromes and evaluating treatments that can prevent transition to psychosis in these ultra-high risk groups. In this review, different kinds of prevention approaches are enumerated and necessary conditions for a disease-prevention strategy are summarized. The broad overlap as well as the significant difference between a schizophrenia prodrome and a 'psychosis-risk syndrome' is discussed and the present status of approaches to identify individuals at increased risk for developing psychosis and schizophrenia are critically examined along with evaluations on therapeutic interventions to reduce these risks. Finally, to conclude, recommendations for current best clinical practice and key questions for the future are suggested.