Psychotic-like experiences in a community sample of adolescents: implications for the continuum model of psychosis and prediction of schizophrenia

Brief screening for psychosis-like experiences

OBJECTIVE

Psychotic-like experiences (PLEs) are common, and are markers of poor mental health. This study examined the internal structure of a screening test, the Community Assessment of Psychic Experiences-Positive scale (CAPE-P) in a young Australian sample.

METHOD

A cross-sectional online survey, which included the CAPE-P, was completed by 1610 university students aged between 18 and 25 years. Confirmatory factor analyses compared 1-, 4-, and 5-factor models, and examined effects of omitting selected items.

RESULTS

A 3-factor model, omitting items on magical thinking, grandiosity, paranormal beliefs and a cross-loading item produced the best fit. The resultant 15-item CAPE (CAPE-P15) had three subscales - Persecutory Ideation, Perceptual Abnormalities and Bizarre Experiences, all with high levels of internal consistency.

CONCLUSION

The CAPE-P15 shows promise as a measure of positive, psychosis-like experiences, but further validation of this measure is required in community samples.

Neurocognition in the extended psychosis phenotype: performance of a community sample of adolescents with psychotic symptoms on the MATRICS neurocognitive battery

Neurocognitive dysfunction is well established in psychosis, but recent work suggests that processing speed deficits might represent a particularly important cognitive deficit. A number of significant confounds, however, such as disease chronicity and antipsychotic medication use, have been shown to affect processing speed, causing debate as to the core cognitive features of psychosis. We adopted a novel strategy of testing neurocognitive performance in the "extended psychosis phenotype," involving community-based adolescents who are not clinically psychotic but who report psychotic symptoms and who are at increased risk of psychosis in adulthood. This allows investigation of the earliest cognitive factors associated with psychosis risk, while excluding potential confounds such as disease chronicity and antipsychotic use. A population sample of 212 school-going adolescents aged 11-13 years took part in this study. Psychotic symptoms were assessed using the psychosis section of the Schedule for Affective Disorders and Schizophrenia. Neurocognition was assessed using the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) consensus neurocognitive battery. Adolescents with psychotic symptoms performed significantly more poorly on 3 processing speed tasks: Trail Making Test-A (F = 3.3, P < .05), Trail Making Test-B (F = 3.1, P < .05), and digit symbol coding task (F = 7.0, P < .001)-as well as on a nonverbal working memory (spatial span) task (F = 3.2, P < .05). Our findings support the idea that neurocognitive impairment, and processing speed impairment in particular, is a core feature of psychosis risk. This group likely demonstrates some of the earliest cognitive impairments associated with psychosis vulnerability.

Knowledge of psychiatric terms and concepts among Kenyan youth: analysis of focus group discussions

Psychiatric disorders and symptoms are common worldwide. However, cultural differences in symptom manifestation and knowledge of psychiatric terms and concepts represent a challenge to accurate clinical assessment. Our previous youth surveys revealed higher rates of psychotic experiences in Kenya compared to several other countries, suggesting culture may influence psychosis risk assessment survey results. The goal of the present investigation is to evaluate understanding of general mental health related terms and concepts and specific items from the Structured Interview for Psychosis-Risk Symptoms (SIPS), a commonly used psychosis risk assessment instrument. Six focus groups were conducted in Nairobi, Kenya and surrounding areas with young adults from the community, university and secondary school students, and mental health professionals. Analysis of the information obtained from participants indicated that adolescents and young adults in Kenya were aware of mental illness in their communities, but had very limited knowledge of the meaning of specific psychiatric disorders and symptoms. Many believed that the cause of mental illness was spiritual in nature. These results suggest that in order to obtain accurate reported rates of psychiatric symptoms, assessment of Kenyan adolescents and young adults requires elaboration of assessment questions and use of simplified terms.

An updated and conservative systematic review and meta-analysis of epidemiological evidence on psychotic experiences in children and adults: on the pathway from proneness to persistence to dimensional expression across mental disorders

BACKGROUND

The psychosis-proneness-persistence-impairment model of psychotic disorder incorporates notions of both phenomenological and temporal continuity (persistence) of psychotic experiences (PE), but not structural continuity. Specific testable propositions of phenomenological continuity and persistence are identified. Method Propositions are tested by systematic reviews of the epidemiology of PE, persistence of PE and disorder outcomes, and meta-analyses (including Monte Carlo permutation sampling, MCPS) of reported rates and odds ratios (ORs).

RESULTS

Estimates of the incidence and prevalence of PE obtained from 61 cohorts revealed a median annual incidence of 2.5% and a prevalence of 7.2%. Meta-analysis of risk factors identified age, minority or migrant status, income, education, employment, marital status, alcohol use, cannabis use, stress, urbanicity and family history of mental illness as important predictors of PE. The mode of assessment accounted for significant variance in the observed rates. Across cohorts, the probability of persistence was very strongly related to the rate of PE at baseline. Of those who report PE, ∼20% go on to experience persistent PE whereas for ∼80%, PE remit over time. Of those with baseline PE, 7.4% develop a psychotic disorder outcome.

CONCLUSIONS

Compelling support is found for the phenomenological and temporal continuity between PE and psychotic disorder and for the fundamental proposition that this relationship is probabilistic. However, imprecision in epidemiological research design, measurement limitations and the epiphenomenological nature of PE invite further robust scrutiny of the continuity theory.

Classes of psychotic experiences in Kenyan children and adolescents

Psychotic-like experiences (PLEs) have been observed worldwide in both adults and children outside the context of a clinical disorder. In the current study, we investigate the prevalence and patterns of PLEs among children and adolescents in Kenya. Among 1,971 students from primary and secondary schools around Nairobi (aged 8-19), 22.1 % reported a lifetime history of a psychotic experience, and 16.3 % reported this unrelated to sleep or drugs. Psychotic experiences were more common in males compared to females. LCA resulted in a three-class model comprised of a normative class (83.3 %), a predominately hallucinatory class (Type 1 psychosis: 9.6 %), and a pan-psychotic class (Type 2 psychosis: 7.2 %). These results indicate that PLEs are prevalent in children and adolescents, and the distributions of symptom clusters are similar to that found in adulthood. The relationship of specific PLEs to the future development of psychotic disorder, functional impairment or distress will require further study.

Psychometric properties of Peters et al. delusions inventory-21 in adolescence

We explored the psychometric properties of the Korean version of the Peters et al. delusions inventory-21 (PDI-21) and evaluated the item characteristics of the PDI-21 compared with the Magical Ideation Scale (MIS) in Korean community adolescents. Survey participants comprised 310 Year 10 students who were assessed with the following instruments: the PDI-21, the MIS, the Schizotypal Personality Scale (STA) and the symptom checklist-90-R (SCL-90-R). The item characteristics of the PDI-21 and MIS were also explored using item response theory (IRT). The PDI-21 exhibited good internal consistency and demonstrated significant correlations with the MIS, STA and all subscale scores of the SCL-90-R, indicating psychological distress in adolescents with high PDI-21 scores. We also found through IRT analysis that the PDI-21 provides more information at the lower range and the MIS at the higher range of delusion proneness. Our findings suggest that the PDI-21 is an effective and reliable self-report measure for assessment of delusion proneness and that the PDI-21 and the MIS may be used complementarily to assess a broad range of delusion proneness among community adolescents.

Psychotic-like symptoms and positive schizotypy are associated with mixed and ambiguous handedness in an adolescent community sample

The objective of this study was to replicate the association between atypical handedness and psychosis-proneness in a representative sample of adolescents from the general population. It expands previous studies by (1) analyzing a variety of atypical handedness indexes (left, mixed, ambiguous, and inconsistent), (2) measuring comprehensively the multidimensionality of psychosis-proneness, and (3) analyzing the association of different patterns of atypical handedness with nonclinical dimensions of both trait (schizotypy) and sub-clinical symptom (psychotic-like experiences) levels. Seven hundred and twenty-eight adolescents were assessed for handedness by the 12-item self-report Annett Hand Preference Questionnaire and for psychosis-proneness by the Oxford-Liverpool Inventory of Feelings and Experiences and the Community Assessment of Psychic Experiences scales. Writing-hand alone did not detect associations between laterality and psychosis-proneness. Mixed- rather than left-handedness was related to psychosis-proneness, and this was more evident when analyzing subjects with ambiguous handedness exclusively. When analysis was restricted to subjects with non-ambiguous handedness, strong left-handedness was related to psychosis-proneness. The positive dimension showed a stronger association than the negative one with atypical handedness. Results partially support mixed-handedness as a marker of developmental disorders underlying both atypical lateralization and psychosis-proneness. Among various possible mixed-handedness patterns, inconsistent hand use across primary actions, and for the same action across time, seems particularly related to psychosis-proneness and thus requires further exploration.

Cannabis use and vulnerability for psychosis in early adolescence--a TRAILS study

AIMS

To examine the direction of the longitudinal association between vulnerability for psychosis and cannabis use throughout adolescence.

DESIGN

Cross-lagged path analysis was used to identify the temporal order of vulnerability for psychosis and cannabis use, while controlling for gender, family psychopathology, alcohol use and tobacco use.

SETTING

A large prospective population study of Dutch adolescents [the TRacking Adolescents' Individual Lives Survey (TRAILS) study].

PARTICIPANTS

A total of 2120 adolescents with assessments at (mean) age 13.6, age 16.3 and age 19.1.

MEASUREMENTS

Vulnerability for psychosis at the three assessment points was represented by latent factors derived from scores on three scales of the Youth Self-Report and the Adult Self-Report, i.e. thought problems, social problems and attention problems. Participants self-reported on cannabis use during the past year at all three waves.

FINDINGS

Significant associations (r = 0.12-0.23) were observed between psychosis vulnerability and cannabis use at all assessments. Also, cannabis use at age 16 predicted psychosis vulnerability at age 19 (Z = 2.6, P < 0.05). Furthermore, psychosis vulnerability at ages 13 (Z = 2.0, P < 0.05) and 16 (Z = 3.0, P < 0.05) predicted cannabis use at, respectively, ages 16 and 19.

CONCLUSIONS

Cannabis use predicts psychosis vulnerability in adolescents and vice versa, which suggests that there is a bidirectional causal association between the two.

Depressive symptoms are associated with (sub)clinical psychotic symptoms in patients with non-affective psychotic disorder, siblings and healthy controls

BACKGROUND

Depression is a clinically relevant dimension, associated with both positive and negative symptoms, in patients with schizophrenia. However, in siblings it is unknown whether depression is associated with subclinical positive and negative symptoms. Method Depressive symptoms and their association with positive and negative symptoms were examined in 813 healthy siblings of patients with a non-affective psychotic disorder, 822 patients and 527 healthy controls. Depressive episodes meeting DSM-IV-TR criteria (lifetime) and depressed mood (lifetime) were assessed with the Comprehensive Assessment of Symptoms and History (CASH) in all three groups. In the patient group, the severity of positive and negative psychosis symptoms was assessed with the CASH. In the siblings and healthy controls, the severity of subclinical psychosis symptoms was assessed with the Community Assessment of Psychic Experiences (CAPE).

RESULTS

Patients reported more lifetime depressed mood and more depressive episodes than both siblings and controls. Siblings had a higher chance of meeting lifetime depressive episodes than the controls; no significant differences in depressed mood were found between siblings and controls. In all three groups the number and duration of depressive symptoms were associated with (sub)clinical negative symptoms. In the patients and siblings the number of depressive symptoms was furthermore associated with (sub)clinical positive symptoms. Finally, lifetime depressed mood showed familial clustering but this clustering was absent for lifetime depressive episodes.

CONCLUSIONS

These findings suggest that a co-occurring genetic vulnerability for both depressive and psychotic symptomatology exists on a clinical and a subclinical level.

Does specific psychopathology predict development of psychosis in ultra high-risk (UHR) patients?

OBJECTIVES

Studies have attempted to identify additional risk factors within the group identified as 'ultra high risk' (UHR) for developing psychotic disorders in order to characterise those at highest risk. However, these studies have often neglected clinical symptom types as additional risk factors. We aimed to investigate the relationship between baseline clinical psychotic or psychotic-like symptoms and the subsequent transition to a psychotic disorder in a UHR sample.

METHOD

A retrospective 'case-control' methodology was used. We identified all individuals from a UHR clinic who had subsequently developed a psychotic disorder (cases) and compared these to a random sample of individuals from the clinic who did not become psychotic within the sampling time frame (controls). The sample consisted of 120 patients (60 cases, 60 controls). An audit tool was used to identify clinical symptoms reported at entry to the clinic (baseline) using the clinical file. Diagnosis at transition was assessed using the Operational Criteria for Psychotic Illness (OPCRIT) computer program. The relationship between transition to a psychotic disorder and baseline symptoms was explored using survival analysis.

RESULTS

Presence of thought disorder, any delusions and elevated mood significantly predicted transition to a psychotic disorder. When other symptoms were adjusted for, only the presence of elevated mood significantly predicted subsequent transition (hazard ratio 2.69, p = 0.002). Thought disorder was a predictor of transition to a schizophrenia-like psychotic disorder (hazard ratio 3.69, p = 0.008).

CONCLUSIONS

Few individual clinical symptoms appear to be predictive of transition to a psychotic disorder in the UHR group. Clinicians should be cautious about the use of clinical profile alone in such individuals when determining who is at highest risk.

Persisting psychotic-like experiences are associated with both externalising and internalising psychopathology in a longitudinal general population child cohort

BACKGROUND

Persisting psychotic-like experiences (PLEs) are associated with an increased risk of internalising symptoms in adolescence. Whether this association holds similarly for externalising symptoms, and from mid-childhood, is unclear. This prospective study investigated the extent to which PLE persistence was associated with internalising and externalising psychopathology in a community sample of children aged 9-11years at study commencement.

METHODS

8099 children (mean age 10.4years) completed questionnaires assessing PLEs, externalising and internalising symptoms. A subsample of 547 children completed reassessment, on average, two years later.

RESULTS

Two-thirds (66%) of children reported PLEs at baseline. Approximately two years later, PLEs persisted in 39% of those children. After adjustment for previous psychopathology and other potential confounds, children with persisting PLEs were at higher risk for internalising (odds ratio [OR]=1.94; 95% confidence interval [CI] 1.13-3.34) and externalising (OR=1.97; 95% CI 1.19-3.26) psychopathology than children whose PLEs remitted; and, than children who never presented PLEs.

CONCLUSIONS

Persistent PLEs from mid-childhood are associated with later internalising and externalising psychopathology in the general population, whereas transitory PLEs may be part of a spectrum of normative childhood development. Interventions that target persistent PLEs may contribute to a reduction in common childhood psychopathology.

Dynamic association between interpersonal functioning and positive symptom dimensions of psychosis over time: a longitudinal study of healthy adolescents

BACKGROUND

Cross-sectional studies have indicated that alterations in social functioning, particularly interpersonal functioning, are associated with the occurrence of psychotic symptoms and experiences at different levels of the extended psychosis phenotype (ranging from population psychometric expression of liability to overt psychotic disorder). However, more research is needed on the development of this association over time.

METHODS

Cross-lagged path modeling was used to analyze bidirectional, longitudinal associations between 4 dimensions of subclinical psychotic experiences (persecutory ideation, bizarre experiences, perceptual abnormalities, and magical thinking) and interpersonal functioning in an adolescent general population sample (N = 881 at T1, N = 652 at T2, and N = 512 at T3) assessed 3 times in 3 years.

RESULTS

All symptom dimensions showed some association with interpersonal functioning over time, but only bizarre experiences and persecutory ideation were consistently and longitudinally associated with interpersonal functioning. Poorer interpersonal functioning predicted higher levels of bizarre experiences and persecutory ideation at later measurement points (both T1 to T2 and T2 to T3).

CONCLUSIONS

Poor interpersonal functioning in adolescence may reflect the earliest expression of neurodevelopmental alterations preceding expression of psychotic experiences in a symptom-specific fashion.

The ultra-high risk concept-a review

Attempts to identify people at imminent risk of psychotic disorder have been made during the past 20 years. High-risk criteria have been developed, and despite findings of a recent decline in the rate of onset of psychosis associated with these criteria, people identified still have a significantly greater risk, compared with the general population. Intervention studies in this group indicate that psychological treatments and fish oil appear to be just as effective as antipsychotics. Future research should refine risk factors for psychosis and examine outcomes other than psychosis. Research is also needed into what harms and benefits are associated with making the high-risk criteria into a formal diagnosis.

Working memory capacity and psychotic-like experiences in a general population sample of adolescents and young adults

Working memory (WM) impairment is a common feature in individuals with schizophrenia and high-risk for psychosis and a promising target for early intervention strategies. However, it is unclear to what extent WM impairment parallels specific behavioral symptoms along the psychosis continuum. To address this issue, the current study investigated the relation of WM capacity with psychotic-like experiences (PLEs) in a large Swedish population sample (N = 1012) of adolescents and young adults (M = 24.4 years, range 12-35). WM was assessed with two online computer tasks: a task where participants had to identify and remember the location of an odd shape and a task of remembering and following instructions. PLE scores were derived from a translated symptom questionnaire (Community Assessment of Psychic Experiences), which includes positive, negative, and depressive symptom scales. Positive and negative symptom scales were further subdivided into symptom clusters based on factor analyses. The results showed that low WM capacity was modestly associated with increased reports of bizarre experiences (BE) and depressive symptoms, after controlling for age, gender, and global symptom scores. Interestingly, when analyses were repeated for separate age groups, low WM was exclusively associated with a higher frequency of BE for young adults (20-27 years) and with depressive symptoms for older adults (28-35 years). These findings suggest that specific PLEs can be indicative of reduced WM capacity in early adulthood, which in turn may reflect an increased risk for psychosis and a greater need for targeted intervention. In contrast, during adolescence individual differences in cognitive development may influence the strength of the relationships and thereby mask potential vulnerabilities for psychopathology.

Identification of young people in the early stages of psychosis: validation of a checklist for use in primary care

The study aims to establish the concordant validity of the Early Detection Primary Care Checklist (PCCL); a 20 item tool designed to help primary care practitioners identify young people in the early stages of psychosis. The checklist was completed by the referring practitioners of 176 young people referred to early detection teams across the UK. The concordant validity of the checklist was established by comparing screen results with a standardised psychiatric assessment for identifying young people who may be at a risk of developing psychosis (CAARMS). Preliminary analysis found that the simple checklist as originally conceived had excellent sensitivity (96%) but poor specificity (10%). Subsequent exploratory analysis led to the development of two better performing models for the combination of item responses to predict CAARMS outcomes. The first retained the use of all 20 checklist items and achieved sensitivity of 89% and specificity of 60%. The second retained six checklist items with p-values of 0.2 or above and achieved sensitivity of 88% and specificity of 47%. Although the initial checklist did not perform well as a screening tool the two models perform well in comparison to other, much longer, screening tools for this population. These tools are not intended as a diagnostic instrument; rather it has been designed as a bridge between primary care and specialist services and to build on the skills and knowledge already held by primary care practitioners. Following a consideration of the limitations of this study, the continued evaluation of the tools performance in practice is recommended.

Basic self-disturbance predicts psychosis onset in the ultra high risk for psychosis "prodromal" population

INTRODUCTION

Phenomenological research indicates that disturbance of the basic sense of self may be a core phenotypic marker of schizophrenia spectrum disorders. Basic self-disturbance refers to a disruption of the sense of ownership of experience and agency of action and is associated with a variety of anomalous subjective experiences. In this study, we investigated the presence of basic self-disturbance in an "ultra high risk" (UHR) for psychosis sample compared with a healthy control sample and whether it predicted transition to psychotic disorder.

METHODS

Forty-nine UHR patients and 52 matched healthy control participants were recruited to the study. Participants were assessed for basic self-disturbance using the Examination of Anomalous Self-Experience (EASE) instrument. UHR participants were followed for a mean of 569 days.

RESULTS

Levels of self-disturbance were significantly higher in the UHR sample compared with the healthy control sample (P < .001). Cox regression indicated that total EASE score significantly predicted time to transition (P < .05) when other significant predictors were controlled for. Exploratory analyses indicated that basic self-disturbance scores were higher in schizophrenia spectrum cases, irrespective of transition to psychosis, than nonschizophrenia spectrum cases.

DISCUSSION

The results indicate that identifying basic self-disturbance in the UHR population may provide a means of further "closing in" on individuals truly at high risk of psychotic disorder, particularly of schizophrenia spectrum disorders. This may be of practical value by reducing inclusion of "false positive" cases in UHR samples and of theoretical value by shedding light on core phenotypic features of schizophrenia spectrum pathology.

Facial emotion recognition in adolescents with psychotic-like experiences: a school-based sample from the general population

BACKGROUND

Psychotic symptoms, also termed psychotic-like experiences (PLEs) in the absence of psychotic disorder, are common in adolescents and are associated with increased risk of schizophrenia-spectrum illness in adulthood. At the same time, schizophrenia is associated with deficits in social cognition, with deficits particularly documented in facial emotion recognition (FER). However, little is known about the relationship between PLEs and FER abilities, with only one previous prospective study examining the association between these abilities in childhood and reported PLEs in adolescence. The current study was a cross-sectional investigation of the association between PLEs and FER in a sample of Irish adolescents.

METHOD

The Adolescent Psychotic-Like Symptom Screener (APSS), a self-report measure of PLEs, and the Penn Emotion Recognition-40 Test (Penn ER-40), a measure of facial emotion recognition, were completed by 793 children aged 10-13 years.

RESULTS

Children who reported PLEs performed significantly more poorly on FER (β=-0.03, p=0.035). Recognition of sad faces was the major driver of effects, with children performing particularly poorly when identifying this expression (β=-0.08, p=0.032).

CONCLUSIONS

The current findings show that PLEs are associated with poorer FER. Further work is needed to elucidate causal relationships with implications for the design of future interventions for those at risk of developing psychosis.

Prevalence of psychotic symptoms in childhood and adolescence: a systematic review and meta-analysis of population-based studies

BACKGROUND

Psychotic symptoms occur more frequently in the general population than psychotic disorder and index risk for psychopathology. Multiple studies have reported on the prevalence of these symptoms using self-report questionnaires or clinical interviews but there is a lack of consensus about the prevalence of psychotic symptoms among children and adolescents.

METHOD

We conducted a systematic review of all published literature on psychotic symptom prevalence in two age groups, children aged 9-12 years and adolescents aged 13-18 years, searching through electronic databases PubMed, Ovid Medline, PsycINFO and EMBASE up to June 2011, and extracted prevalence rates.

RESULTS

We identified 19 population studies that reported on psychotic symptom prevalence among children and adolescents. The median prevalence of psychotic symptoms was 17% among children aged 9-12 years and 7.5% among adolescents aged 13-18 years.

CONCLUSIONS

Psychotic symptoms are relatively common in young people, especially in childhood. Prevalence is higher in younger (9-12 years) compared to older (13-18 years) children.

Etiopathogenic perspectives on chronic psycho traumatic and chronic psychotic symptoms: the hypothesis of a hyperdopaminergic endophenotype of PTSD

Post traumatic stress disorder (PTSD) is a complex and heterogeneous disorder, which specific symptoms are re-experiencing, increased arousal and avoidance of stimuli associated with the trauma. PTSD has much comorbidity like depression, substance abuse, somatic complaints, repeated dissociative phenomena and transitory or chronic psychotic reactions. PTSD can manifest itself in different clinical forms: some patients present higher symptoms in one domain as compared to another, probably because of abnormalities in different neurobiological systems. Hyposerotonergic and hypernoradrenergic PTSD endophenotypes have been previously identified and the purpose of this paper is to focus on the hypothesis of a hyperdopaminergic endophenotype. The current review discusses several entities: PTSD with psychotic features with or without depression, the comorbide use of psychoactive substances that increase psychotic symptoms and traumatic brain injuries as agents of psycho traumatic and psychotic features. For all of these nosographic entities, the dopaminergic neuromodulation may play a central role. The hypothesis of a hyperdopaminergic endophenotype of PTSD opens up new research and therapeutic perspectives. Although antipsychotics are frequently used for people with PTSD further studies are needed to develop a consensus on the guidelines for treating the psychotic forms of PTSD.

Young people at ultra high risk for psychosis: research from the PACE clinic

Over the last fifteen years, attempts have been made to prospectively identify individuals in the prodromal phase of schizophrenia and other psychotic disorders. The ultra high risk approach, based on a combination of known trait and state risk factors, has been the main strategy used. The validation of the ultra high risk criteria allowed for predictive research in this population in an attempt to identify clinical, neurocognitive and neurobiological risk factors for psychosis onset. It also led to a series of intervention studies in this population, which have included the use of low dose antipsychotic medication, cognitive therapy, and omega-3 fatty acids. Although there is moderate evidence for the effectiveness of specific intervention strategies in this population, the most effective type and duration of intervention is yet to be determined. A current controversy in the field is whether to include an adaption of the ultra high risk criteria (the attenuated psychosis syndrome) in the next version of the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition).

Prevalence and clinical features of Thought-Perception-Sensitivity Symptoms: results from a community survey of Korean high school students

Epidemiologic research indicates that psychosis and depression most frequently develop during adolescence. Hence, an efficient strategy for improving youth mental health would be to focus on detection of early-stage psychosis and depression in adolescence. In this study, 1461 high school students were surveyed using self-report scales. Students who scored equal to or above the cut-off value on any of the scales and who agreed to a further examination proceeded to a second assessment, using the Kiddie Schedule for Affective Disorders and Schizophrenia and Comprehensive Assessment of At-Risk Mental States along with self-reporting scales. The estimated prevalence of adolescents at ultra-high risk (UHR) for psychosis and of depression-spectrum disorders was 1.26 and 3.69% respectively. Compared with the normal group, experiences of bullying, suicidal ideation, and suicide attempts were significantly higher in these two groups; the subjects at UHR for psychosis were found to have significantly lower academic performance and lower ratings on SCRS; and submissive behavior was more prevalent in the depression-spectrum group. Our results reveal several clinical features of adolescents at UHR for psychosis and with depression-spectrum disorder and underscore the importance of accurate assessment of and early appropriate care for these adolescents.

Psychotic experience subtypes, poor mental health status and help-seeking behaviour in a community sample of young adults

BACKGROUND

Different subtypes of psychotic experiences (PEs) have been identified in clinical and non-clinical samples. Researchers have considered these PEs to either be variations of personality or expressions of vulnerability to psychotic disorder. This study aimed to determine which particular subtypes of PEs were more likely to be associated with poor mental health status and help-seeking behaviour in a non-clinical sample of young adults.

METHODS

The study was conducted on a community sample of 997 young adults. The prevalence of PEs and distress was measured using the community assessment of psychic experiences (CAPE), depressive and anxiety symptoms were measured using Beck depression inventory-II and Beck anxiety inventory, and general functioning was measured using the general health questionnaire-12. Factorial analysis of the CAPE positive dimension was conducted and correlations between factors and clinical variables were analysed.

RESULTS

Four PE subtypes were identified: perceptual abnormalities, persecutory ideas (PI), bizarre experiences, and magical thinking. At least one high frequency PI was endorsed by 60.8% (n = 606) of the sample and proved to be significantly associated both with poor mental health status and help-seeking behaviour.

CONCLUSION

PEs subtypes are differentially associated with various markers of poor mental health status. PI seem to have stronger psychopathological significance than other subtypes of PEs. Further longitudinal studies are required to extend these findings.

Distress, defiance or adaptation? A review paper of at-risk mental health states in young offenders

AIM

This paper firstly aims to explore the prevalence of mental health problems in young offenders and secondly, to review the factors which mean a young offender is at risk of developing more serious and chronic mental health problems, including psychosis.

METHODS

The literature in this field will be reviewed, and the highlighted risk factors explored in detail.

RESULTS

Reviewing the evidence base highlights the complex needs of this population, as the prevalence of mental health problems in both detained and community-based young offenders is high, with the presence of at least one mental health problem found in up to 92%. There is much data to suggest that young offenders have many of the risk indicators that would place them at risk of significant mental health problems according to previously identified criteria. Factors such as intellectual level, difficulties in school, substance abuse problems, exposure to trauma and problems understood within an attachment framework are explored.

CONCLUSION

The main conclusion is that this population have many risk factors which increase the possibility of developing serious mental health problems, therefore highlighting the need for early intervention.

Reliability and sources of validity evidence of the Oviedo Schizotypy Assessment Questionnaire-Abbreviated (ESQUIZO-Q-A)

The main goal of this research was to examine the reliability and different sources of validity evidence of the Oviedo Schizotypy Assessment Questionnaire-Abbreviated (ESQUIZO-Q-A) in nonclinical adolescents. The final sample was made up of 1,455 participants, 705 males (48.5%), with a mean age of 15.92 years (SD = 1.18). The internal consistency of the subscales ranged from .62 to .75. The analysis of its internal structure yielded a three-dimensional solution based on the dimensions: Reality Distortion, Anhedonia, and Interpersonal Disorganization. Likewise, the goodness-of-fit indices derived from the Confirmatory Factor Analysis for the hypothesized three-factor model were adequate. The three dimensions of the ESQUIZO-Q-A were significantly correlated with the subscales of the Strengths and Difficulties Questionnaire. The ESQUIZO-Q is a brief and simple self-report with adequate psychometric properties for the assessment of schizotypal traits in nonclinical adolescent populations. Future research should continue to explore the metric quality of the ESQUIZO-Q-A (e.g., sensitivity and specificity) and incorporate the new advances in psychological and educational assessment such as Computerized Adaptive Testing.

Replication of the five-dimensional structure of positive psychotic experiences in young adulthood

Previous work has examined the structure of subclinical positive psychotic experiences. The current study, using confirmatory factor analysis in a general population sample of young adult females, replicated a five-dimensional model, which showed excellent model fit. The results suggest stability of the five-dimensional model across adolescent and young adult life.

Prevalence and characteristics of psychotic-like experiences in Kenyan youth

Current evidence suggests that there may be significant differences in psychotic symptom prevalence in Africa compared with other cultures. However, there have been few studies evaluating these symptoms in the continent. We conducted a cross-sectional survey of psychotic-like experiences (PLEs) in 2963 Kenyan students from seven tertiary academic institutions spread across Kenya, using a self-administered psychosis questionnaire evaluating psychotic experiences and demographic variables. Logistic regression was used to evaluate relationship between PLEs and demographic variables. Latent class analysis (LCA) was used to determine specific classes of psychotic experiences. Twenty-three percent of respondents reported having at least one PLE, and 19% reported this unrelated to drug use or sleep. Compared to students identifying as Protestant Christians, Catholics had a lower likelihood of having any PLE or visual hallucinations. Other demographic variables were not significantly associated with PLEs. LCA of PLEs resulted in a three-class model that comprised 1) a non-psychotic class (83.8%), 2) a predominantly hallucinatory class ("type I PLE"; 12.7%), and 3) a multiple symptom class ("type II PLE"; 3.5%). Both psychotic classes had a predominance of male students. Further studies are required to clarify functionality and clinical progression associated with observed patterns of psychosis, as well as the generalizability of our findings.

Analysis of the multidimensionality of hallucination-like experiences in clinical and nonclinical Spanish samples and their relation to clinical symptoms: implications for the model of continuity

Numerous studies have found that hallucinatory experiences occur in the general population. But to date, few studies have been conducted to compare clinical and nonclinical groups across a broad array of clinical symptoms that may co-occur with hallucinations. Likewise, hallucination-like experiences are measured as a multidimensional construct, with clinical and subclinical components related to vivid daydreams, intrusive thoughts, perceptual disturbance, and clinical hallucinatory experiences. Nevertheless, these individual subcomponents have not been examined across a broad spectrum of clinically disordered and nonclinical groups. The goal of the present study was to analyze the differences and similarities in the distribution of responses to hallucination-like experience in clinical and nonclinical populations and to determine the relation of these hallucination-like experiences with various clinical symptoms. These groups included patients with schizophrenia, non-psychotic clinically disordered patients, and a group of individuals with no psychiatric diagnoses. The results revealed that hallucination-like experiences are related to various clinical symptoms across diverse groups of individuals. Regression analysis found that the Psychoticism dimension of the Symptom Check List (SCL-90-R) was the most important predictor of hallucination-like experiences. Additionally, increased auditory and visual hallucination was the only subcomponent that differentiated schizophrenic patients from other groups. This distribution of responses in the dimensions of hallucination-like experiences suggests that not all the dimensions are characteristic of people hearing voices. Vivid daydreams, intrusive thoughts, and auditory distortions and visual perceptual distortions may represent a state of general vulnerability that does not denote a specific risk for clinical hallucinations. Overall, these results support the notion that hallucination-like experiences are closer to a quasi-continuum approach and that total scores on these scales explain a state of vulnerability to general perceptual disturbance.

Identification and characterization of prodromal risk syndromes in young adolescents in the community: a population-based clinical interview study

While a great deal of research has been conducted on prodromal risk syndromes in relation to help-seeking individuals who present to the clinic, there is a lack of research on prodromal risk syndromes in the general population. The current study aimed first to establish whether prodromal risk syndromes could be detected in non-help-seeking community-based adolescents and secondly to characterize this group in terms of Axis-1 psychopathology and general functioning. We conducted in-depth clinical interviews with a population sample of 212 school-going adolescents in order to assess for prodromal risk syndromes, Axis-1 psychopathology, and global (social/occupational) functioning. Between 0.9% and 8% of the community sample met criteria for a risk syndrome, depending on varying disability criteria. The risk syndrome group had a higher prevalence of co-occurring nonpsychotic Axis-1 psychiatric disorders (OR = 4.77, 95% CI = 1.81-12.52; P < .01) and poorer global functioning (F = 24.5, df = 1, P < .0001) compared with controls. Individuals in the community who fulfill criteria for prodromal risk syndromes demonstrate strong similarities with clinically presenting risk syndrome patients not just in terms of psychotic symptom criteria but also in terms of co-occurring psychopathology and global functioning.

Mindfulness-Based Intervention on Distressing Hallucination-Like Experiences in a Nonclinical Sample

The presence of psychotic-like experiences in the general population has been amply reported. Nevertheless, the degree of concern or anxiety that such experiences may generate is an aspect that has not received as much appraisal. In this sense, mindfulness is an approach to intervention based on the modification of the individual's relationship with the symptoms, instead of their elimination. The goal of the present study is to compare the effect of mindfulness training on distressing hallucination-like experiences. Eighteen participants were assigned to the experimental group, and they received 8 sessions of mindfulness training; 20 participants were assigned to a control group that viewed 8 sessions of a video forum. The results showed that upon completing the mindfulness training, there was a significant and large effect on the decrease of anxiety caused by hallucination-like experiences. These results were maintained at the 16-week follow-up. The repercussions of these results are underlined.

Schizotypy, emotional-behavioural problems and personality disorder traits in a non-clinical adolescent population

The main goal of the present study was to examine the relationship between the schizotypy dimensions, emotional-behavioural problems and personality disorder traits in non-clinical general adolescent population. A total of 1455 participants (M=15.9years; S.D.=1.2) were administered the Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q), the Strengths and Difficulties Questionnaire (SDQ) and the Personality Diagnostic Questionnaire-4+ (PDQ-4+). Correlation analyses revealed significant associations between the schizotypy and emotional-behavioural problems self-reported by adolescents. Participants with high scores in schizotypy dimensions, reported higher rates of affective and behavioural problems than those with low scores. Also, schizotypy dimensions and personality disorder traits were closely related in adolescent population. These data indicate, as occurs in clinical samples, the high overlap between schizotypy and personality disorder traits. Affective dysregulation and behavioural problems are present at the subclinical level in non-clinical adolescent population. These results have implications for the integration of schizotypy studies within the paradigms of developmental psychology and dimensional models of personality.

Measurement invariance of the Schizotypal Personality Questionnaire-Brief across gender and age

The purpose of this study was to examine the dimensional structure and measurement invariance of the Schizotypal Personality Questionnaire-Brief (SPQ-B) (Raine and Benishay, 1995) across sex and age in a representative sample of nonclinical adolescents and young adults. The sample consisted of 1789 adolescents and young adults (42.1% males), with a mean age of 17.1years (S.D.=2.9). The results indicated that the Likert version of the SPQ-B showed adequate psychometric properties (α total score 0.89). The schizotypal personality models that presented the best fit indices were Raine et al.'s (1994) three-factor model and Stefanis et al.'s (2004) four-factor model. In addition, the results support the measurement invariance of the SPQ-B across sex and age. When the latent means of the schizotypal dimensions were compared across sex and age, statistically significant differences were found. Consistent with previous literature, schizotypal personality is a multidimensional construct whose structure appears invariant across sex and age. Future studies should examine the invariance of schizotypal personality across cultures, as well as using the SPQ-B as a screening method in the general population to detect individuals at risk for schizophrenia-spectrum disorders, given its rapid and easy administration.

The relationship between coping and subclinical psychotic experiences in adolescents from the general population--a longitudinal study

BACKGROUND

Subclinical psychotic experiences during adolescence may represent liability for developing psychotic disorder. Both coping style and the degree of persistence of psychotic experiences may play a role in the progression to clinical psychotic disorder, but little is known about the causal relationship between the two.

METHOD

Path modelling was used to examine longitudinal relationships between subclinical positive psychotic experiences and three styles of coping (task-, emotion- and avoidance-oriented) in an adolescent general population sample (n=813) assessed three times in 3 years. Distinct developmental trajectories of psychotic experiences, identified with growth mixture modelling, were compared on the use of these coping styles.

RESULTS

Over time, emotion-oriented coping in general was bi-directionally related to psychotic experiences. No meaningful results were found for task- or avoidance-oriented coping. Females reported using a wider range of coping styles than males, but the paths between coping and psychotic experiences did not differ by gender. Persistence of psychotic experiences was associated with a greater use of emotion-oriented coping, whereas a decrease in experiences over time was associated with an increased use of task-orientated coping.

CONCLUSIONS

Emotion-oriented coping is the most important coping style in relation to psychotic experiences, as it may contribute to a 'vicious cycle' and is associated with persistence of experiences. In addition, more task-oriented coping may result in a decrease in psychotic experiences. Results suggest that opportunities for intervention may already be present at the level of subclinical psychosis.

Evidence for a persistent, environment-dependent and deteriorating subtype of subclinical psychotic experiences: a 6-year longitudinal general population study

BACKGROUND

Research suggests that subclinical psychotic experiences during adolescence represent the behavioral expression of liability for psychosis. Little is known, however, about the longitudinal trajectory of liability in general population samples.

METHOD

Growth mixture modeling was used to examine longitudinal trajectories of self-reported positive psychotic experiences in the Youth Self Report (YSR), completed three times over a period of 6 years by a general population cohort of adolescents aged 10-11 years at baseline (n=2230).

RESULTS

Four groups with distinct developmental trajectories of low, decreasing, increasing and persistent levels of mild positive psychotic experiences were revealed. The persistent trajectory was associated strongly with cannabis use, childhood trauma, developmental problems and ethnic minority status, and consistently displayed strong associations with factors known to predict transition from subclinical psychotic experience to clinical psychotic disorder (severity of and secondary distress due to psychotic experiences, social and attentional problems and affective dysregulation) and also with high levels of parental-reported psychotic experiences and use of mental health care at the end of the follow-up period. Progressively weaker associations were found for the increasing, decreasing and low trajectories respectively.

CONCLUSIONS

The results suggest that the outcome of early developmental deviation associated with later expression of psychotic experiences is contingent on the degree of later interaction with environmental risks inducing, first, persistence of psychotic experiences and, second, progression to onset of need for care and service use. Insight into the longitudinal dynamics of risk states in representative samples may contribute to the development of targeted early intervention in psychosis.

Improving cognitive treatments for delusions

A clear challenge for schizophrenia research is to improve markedly the efficacy of psychological treatments for delusional beliefs. Effect sizes for the first generation of cognitive approaches are weak to moderate. These therapies now lag behind the transformation over the past ten years in understanding the causes of delusions. This paper advocates an interventionist-causal model approach: to focus on one putative causal factor at a time, show that an intervention can change it, and examine the subsequent effects on the delusional beliefs. A number of new studies that illustrate this approach with patients with schizophrenia spectrum disorders who have not responded to previous treatment are reviewed. These early stage studies show great promise in terms of efficacy, although remain to be subjected to methodologically rigorous evaluation. The advantages and difficulties of the interventionist approach applied to psychosis are considered, and future studies are highlighted. The importance for clinical services of cognitive approaches to psychosis will increase further if the theoretical advances can be translated into treatment.

Differential results between self-report and interview-based ratings of risk symptoms of psychosis

AIM

Assessing potential risk of developing psychosis has gained growing attention in recent literature. The selection of suitable assessment methods is the central question for this research endeavour. Whereas prodromal detection instruments are mostly interview-based instruments, there are short screening instruments for self-report use.

METHODS

Difference in psychosis risk scores was tested between self-report results and interview results, with risk symptoms of psychosis included in PROD screening instrument. Subjects were recruited by an early intervention team in Finland.

RESULTS

There was a significant difference between psychosis risk scores based on self-report versus interview in a sample of adolescents (n=87; P<0.001).

CONCLUSIONS

Results suggest that when using screening instruments, risk scores and risk status may vary by the method the information is collected. Checking self-report results by an additional interview is recommended for both clinical and scientific uses.

Symptoms associated with psychosis risk in an adolescent birth cohort: improving questionnaire utility with a multidimensional approach

AIM

Specialized self-report questionnaires have been developed for detection of symptoms indicative of psychosis risk. The identification of at-risk individuals is typically based on sum scores, which assume equal severity and discriminability of all symptoms, and a single dimension of illness. Our aim was to test whether separable dimensions of risk could be identified in the general population.

METHODS

We explored the latent structure of one such questionnaire using full-information item factor analysis, deriving exploratory models from the PROD-Screen questionnaire responses of the adolescent general population based on the Northern Finland 1986 Birth Cohort (n=6611).

RESULTS

A three-dimensional factor structure of positive, negative and general symptoms emerged. The factor structure, the appropriateness of the statistical model and the application of the results to the detection of heightened psychosis risk are discussed.

CONCLUSIONS

In explicitly taking into account the multidimensionality and varying symptom severity of the included items, the current model provides an improvement in questionnaire-based assessment of psychosis risk.

Subclinical psychosis and depression: co-occurring phenomena that do not predict each other over time

BACKGROUND

The path from subclinical psychotic experiences to clinical disorder is thought to be mediated by the persistence of subclinical psychotic experiences. One of the factors that is likely associated with this persistence is depression. Although commonly viewed as interrelated concepts, the exact relationship between subclinical psychosis and depression is not clear.

METHODS

Cross-lagged path modeling was used to explore the relationship between subclinical psychosis and depression across and over time in an adolescent population seeking assistance for non-psychotic disorders (N=138), measured at four occasions over a two-year period.

RESULTS

Subclinical psychosis and depression were related to each other at every cross-sectional measurement, but did not predict each other over time. Subclinical psychotic experiences and depressive symptom levels were highest at baseline, when participants presented to the clinical service for help. In addition, the relationship between them was also strongest at baseline and decreased significantly over time.

CONCLUSION

The results suggest that psychosis and depression are interrelated phenomena that strongly co-occur in time, but longitudinally, one does not predict change in the other. Both psychopathological dimensions should be addressed when treatment is provided to adolescent help-seekers.

The structure of the extended psychosis phenotype in early adolescence--a cross-sample replication

The extended psychosis phenotype, or the expression of nonclinical positive psychotic experiences, is already prevalent in adolescence and has a dose-response risk relationship with later psychotic disorder. In 2 large adolescent general population samples (n = 5422 and n = 2230), prevalence and structure of the extended psychosis phenotype was investigated. Positive psychotic experiences, broadly defined, were reported by the majority of adolescents. Exploratory analysis with Structural Equation Modelling (Exploratory Factor Analysis followed by Confirmatory Factor Analysis [CFA]) in sample 1 suggested that psychotic experiences were best represented by 5 underlying dimensions; CFA in sample 2 provided a replication of this model. Dimensions were labeled Hallucinations, Delusions, Paranoia, Grandiosity, and Paranormal beliefs. Prevalences differed strongly, Hallucinations having the lowest and Paranoia having the highest rates. Girls reported more experiences on all dimensions, except Grandiosity, and from age 12 to 16 years rates increased. Hallucinations, Delusions, and Paranoia, but not Grandiosity and Paranormal beliefs, were associated with distress and general measures of psychopathology. Thus, only some of the dimensions of the extended psychosis phenotype in young people may represent a continuum with more severe psychopathology and predict later psychiatric disorder.

Cannabis use at a young age is associated with psychotic experiences

BACKGROUND

Cannabis use is associated with psychosis and a range of subclinical psychiatric symptoms. The strength of this association depends on dosage and age at first use. The current study investigates whether level of cannabis exposure and starting age are associated with specific profiles of subclinical symptoms.

METHOD

We collected cross-sectional data from a young adult population sample by administering an online version of the Community Assessment of Psychic Experiences (CAPE). Cannabis exposure was quantified as the amount of Euros spent on cannabis per week and the age of initial cannabis use. The primary outcome measure was the odds ratio (OR) to belong to the highest 10% of scores on the total CAPE and the positive-, negative- and depressive symptom dimensions.

RESULTS

In 17 698 adolescents (mean age 21.6, s.d.=4.2 years), cannabis use at age 12 years or younger was strongly associated with a top 10% score on psychotic experiences [OR 3.1, 95% confidence interval (CI) 2.1-4.3] and to a lesser degree with negative symptoms (OR 1.7, 95% CI 1.1-2.5). The OR of heavy users (>€25/week) for negative symptoms was 3.4 (95% CI 2.9-4.1), for psychotic experiences 3.0 (95% CI 2.4-3.6), and for depressive symptoms 2.8 (95% CI 2.3-3.3).

CONCLUSIONS

Early start of cannabis use is strongly associated with subclinical psychotic symptoms and to a lesser degree with negative symptoms, while smoking high amounts of cannabis is associated with increased levels of all three symptom dimensions: psychotic, negative and depressive. These results support the hypothesis that the impact of cannabis use is age specific.

Antibodies to infectious agents and the positive symptom dimension of subclinical psychosis: The TRAILS study

Infections have been suggested to play a role in the etiology of schizophrenia, but the evidence for this has been inconsistent. Schizophrenia patients have an increased risk of infections as a result of hospitalizations or life style factors. Therefore a study on early subclinical manifestations of psychosis in relation to virus infections is warranted. We examined whether serum antibodies against human Herpes viruses and Toxoplasma gondii were associated with subclinical symptoms of psychosis in adolescents. Data were collected as part of the TRacking Adolescents' Individual Lives Survey (TRAILS) cohort, a large prospective cohort of Dutch adolescents. A total of 1176 participants with an available Community Assessment of Psychic Experiences (CAPE) and an available blood sample were included in this analysis. Solid-enzyme immunoassay methods were used to measure the presence of immunoglobulin G (IgG) antibodies in serum to the Herpes virus family and to T. gondii. There was no significant association between serologic evidence of infection with human Herpes viruses or T. gondii and the risk of subclinical positive experience of psychosis. Subjects with a positive serological reaction to Epstein-Barr Virus (EBV) had higher scores on the positive dimension of psychosis measured by CAPE (b=0.03, P=0.02). This significant association was observed in males, but not in females. The current study suggests that there is no significant association between serological evidence of infection to human Herpes viruses and positive subclinical experience of psychosis, whereas there was an association between EBV infection and subclinical psychotic symptoms in boys.

The association between family history of mental disorder and delusional-like experiences: a general population study

Recent studies have indicated that isolated delusional-like experiences (DLE) are common in the general population. Furthermore, there is preliminary evidence to suggest that these experiences are more common in those with a family history of mental disorders. We had the opportunity to explore the association between family history of a wide range of mental disorders and DLE in an Australian general population survey. The Australian National Survey of Mental Health and Wellbeing 2007 examined 8,841 adult community residents. The Composite International Diagnostic Interview was used to generate various DSM-IV lifetime diagnoses and to assess DLE. The participants were asked to report mental disorders in their first-degree relatives. The influence of family history of mental disorders on DLE endorsement was assessed with logistic regression, with adjustments for age, sex, and the presence of comorbid psychiatric diagnoses in the respondents. A family history of anxiety, depression, schizophrenia, bipolar disorder, or alcohol or illicit drug abuse/dependence was each significantly associated with endorsement of DLE, and these associations remained significant when we adjusted for the presence of mental illness in the respondents. When we examined a more restrictive definition of DLE, only a family history of depression and schizophrenia remained significantly associated with DLE. DLE are associated with a family history of a wide range of mental disorders. These findings suggest that familial factors associated with DLE may be shared with a wide range of common mental disorders.

Validity of the 12-item General Health Questionnaire (GHQ-12) in detecting depressive and anxiety disorders among high school students

Despite the common use of the 12-item General Health Questionnaire (GHQ-12) with adolescents, there is limited data supporting its validity with this population. The aims of the study were to investigate the psychometric properties of the GHQ-12 among high school students, to validate the GHQ-12 against the gold standard of a diagnostic interview, and to suggest a threshold score for detecting depressive and anxiety disorders. Six hundred and fifty-four high school students from years 10 to 12 (ages 15-18) completed the GHQ-12 (Likert scored) and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-IV-Test Revision (DSM-IV-TR). Receiver operating characteristic (ROC) curves were plotted. The mean GHQ-12 score for the total sample was 9.9 (S.D.=5.4). Results from the ROC curve indicated that the GHQ-12 performed better than chance at identifying depressive and anxiety disorders (area under the curve (AUC)=0.781). A GHQ-12 threshold score of 9/10 for males and 10/11 for females was found to be optimal. Given the significant proportion of mental illness among high school students, there may be a need to introduce screening for mental illnesses as part of the school curriculum. This can assist with the early identification and enable low stigma preventive intervention within the school environment.

Schizotypal traits and depressive symptoms in nonclinical adolescents

The main goal of this study was to examine the relationship between schizotypal personality traits and depressive symptoms in a sample of nonclinical adolescents. The Schizotypal Personality Questionnaire-Brief (J Personal Disord 1995;9:346-355) and the Reynolds Depression Adolescent Scale (Reynolds WM. Reynolds Adolescent Depression Scale. Professional Manual. Odessa: Psychological Assessment Resources, Inc; 1987) were administered. The sample was made up of 1384 adolescents (48.6% boys), with a mean (SD) age of 15.7 (1.0) years. The results of the study indicate a high degree of overlap between schizotypal experiences and depressive symptoms at a nonclinical level. Canonical correlation between the Schizotypal Personality Questionnaire-Brief scales and the Reynolds Adolescent Depression Scale scales was 0.63, which represents 39.69% of the associated variance between the 2 sets of variables. Confirmatory factor analysis showed that the 4-dimensional model made up of the Positive, Interpersonal, Disorganized, and Depressive dimensions was that which best fit the data. Moreover, the dimensional structure underlying the schizotypal traits and depressive symptoms was found to be invariant across sex and age. These findings converge with data found in previous studies of both patients with schizophrenia and nonclinical adults and suggest that affective dysregulation is also present at a subclinical level. Future research should continue to make progress in the early detection of participants at risk of developing schizophrenia-spectrum disorders based on the early identification of these types of subclinical traits.

'Theory of Mind', psychotic-like experiences and psychometric schizotypy in adolescents from the general population

This study examined 'Theory of Mind' (ToM) functioning, its association with psychometric schizotypy and with self-reported psychotic-like experiences (PLEs) and depressive symptoms, in a community sample of adolescents. Seventy-two adolescents (mean age 14.51years) from Barcelona, Spain, completed questionnaires assessing PLEs, depressive symptoms, and schizotypy. A verbal ToM task and a vocabulary test were administered. The effect of symptomatology, vocabulary ability, age, and gender on task performance was explored. Neither total score on schizotypy nor PLEs were associated with ToM performance. A significant effect of vocabulary on adolescent's performance of both ToM and control stories was found. ToM showed significant negative associations with positive schizotypy, and with one cluster of positive PLEs: first-rank experiences. Positive significant associations between ToM and persecutory delusions and the impulsive aspects of schizotypy were found. Depressive symptoms did not affect ToM performance. Positive schizotypal traits and first-rank symptoms are associated with ToM deficits in adolescents. Results support the trait-(versus state-) dependent notion of ToM impairments in schizophrenia. ToM may be a developmental impairment associated with positive schizotypy and PLEs.

Psychotic-like experiences and depressive symptoms in a community sample of adolescents

PURPOSE

Studies of psychotic-like experiences (PLEs) within community samples of adolescents have explored predominantly positive experiences. There is a paucity of research examining the prevalence and correlates of negative PLEs, and whether particular subtypes of negative PLEs can be identified among the general population of adolescents. This study examined the association of both positive and negative PLEs with depressive symptoms, including detailed analysis of subtypes of positive and negative psychosis dimensions.

METHOD

A community sample of 777 adolescents (50.9% girls: mean age 14.4 years) completed a questionnaire assessing positive and negative PLEs and depressive symptoms.

RESULTS

Principal component factor analysis identified four factors of positive symptoms (persecutory ideation, grandiose thinking, first-rank/hallucinatory experiences and self-referential thinking), and three factors of negative symptoms (social withdrawal, affective flattening, and avolition). Depressive symptoms were associated positively with persecutory ideation, first-rank/hallucinatory experiences, social withdrawal, and avolition, whereas grandiose thinking related negatively with depressive symptoms. Neither self-referential thinking nor affective flattening related to self-reported depression.

CONCLUSIONS

These findings support the view that not all types of positive and negative PLEs in adolescence are associated with depression and, therefore, they may not confer the same vulnerability for psychotic disorders.

Young people at ultra high risk for psychosis: a research update

AIM

Over the last fifteen years attempts have been made to prospectively identify individuals in the prodromal phase of schizophrenia and other psychotic disorders. The 'ultra high risk' approach, based on a combination of known trait and state risk factors, has been the main strategy used. The validation of the ultra high risk criteria led to a series of intervention studies in this population. The aim of this paper is to provide an overview of ultra high risk research.

METHOD

We review studies in this area, focusing on intervention research. Intervention studies have included the use of low dose antipsychotic medication, cognitive therapy, and omega-3 fatty acids.

RESULTS

The evidence for specific intervention strategies for this population is moderate and requires replication with larger samples.

CONCLUSION

Recently, it has been proposed to include an adaption of the ultra high risk criteria in the next version of the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition). This has raised some controversy in the field. The authors conclude that it would be premature to include the Risk Syndrome in the Diagnostic and Statistical Manual of Mental Disorders at this stage.