Psychotic-like experiences in major depression and anxiety disorders: a population-based survey in young adults

Attenuated psychosis syndrome: don't jump the gun

Attenuated psychosis syndrome (APS) was introduced in DSM-5 as a condition for further study. A number of concerns have been raised regarding APS, including its validity as a clinical entity, issues relating to stigma, the potential that it is an unnecessary diagnosis of what might be a self-limiting phase of attenuated psychotic symptoms, and treatment implications of the diagnosis. The current paper presents a number of conceptual and practical issues that should be addressed in deciding whether APS should be accepted as an official diagnosis in subsequent editions of DSM. These include the problem of transferring the established validity of 'at-risk' criteria to APS given some non-trivial differences between the criteria sets, the relationship between attenuated psychotic symptoms and other presenting non-psychotic disorders, the difficulties of operationalising the subthreshold or 'attenuated' concept in standard clinical practice, and the likelihood of the diagnosis leading to overprescription of antipsychotic medication for this group of patients.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Self-reported psychotic-like experiences are a poor estimate of clinician-rated attenuated and frank delusions and hallucinations

BACKGROUND

One reason for the decision to delay the introduction of an Attenuated Psychosis Syndrome in the main text of the fifth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders was the concern that attenuated psychotic symptoms (APS) might in fact be common features in adolescents and young adults from the general population of no psychopathological significance in themselves. This concern was based on reports of high prevalence rates of psychotic-like experiences (PLEs) in the general population and the assumption that PLEs are a good estimate of APS. Although the criterion validity of self-reported PLEs had already been studied with respect to clinician-rated psychotic symptoms and found insufficient, it had been argued that PLEs might in fact be more comparable with mild, subclinical expressions of psychotic symptoms and, therefore, with APS. The present paper is the first to specifically study this assumption.

SAMPLING AND METHODS

The sample consisted of 123 persons seeking help at a service for the early detection of psychosis, of whom 54 had an at-risk mental state or psychosis, 55 had a nonpsychotic mental disorder and 14 had no full-blown mental disorder. PLEs were assessed with the Peters Delusion Inventory and the revised Launay-Slade Hallucination Scale, and psychotic symptoms and APS were assessed with the Structured Interview for Prodromal Syndromes.

RESULTS

At a level of agreement between the presence of any PLE (in 98.4% of patients) and any APS (in 40.7%) just exceeding chance (κ = 0.022), the criterion validity of PLEs for APS was insufficient. Even if additional qualifiers (high agreement or distress, preoccupation and conviction) were considered, PLEs (in 52.8%) still tended to significantly overestimate APS, and agreement was only fair (κ = 0.340). Furthermore, the group effect on PLE prevalence was, at most, moderate (Cramer's V ≤ 0.382).

CONCLUSIONS

The prevalence of APS cannot be deduced from studies of PLEs. Thus, the high population prevalence rate of PLEs does not allow the conclusion that APS are common features of no pathological significance and would lack clinical validity as an Attenuated Psychosis Syndrome in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition. Rather, the population prevalence rate of APS has to be assumed to be largely unknown at present but is likely lower than indicated by epidemiological studies of PLEs. Therefore, dedicated studies are warranted, in which APS are assessed in a way that equates to their clinical evaluation.

Comorbid depressive and anxiety disorders in 509 individuals with an at-risk mental state: impact on psychopathology and transition to psychosis

BACKGROUND

The current diagnostic system for subjects at enhanced clinical risk of psychosis allows concurrent comorbid diagnoses of anxiety and depressive disorders. Their impact on the presenting high-risk psychopathology, functioning, and transition outcomes has not been widely researched.

METHODS

In a large sample of subjects with an At-Risk Mental State (ARMS, n = 509), we estimated the prevalence of DSM/SCID anxiety or depressive disorders and their impact on psychopathology, functioning, and psychosis transition. A meta-analytical review of the literature complemented the analysis.

RESULTS

About 73% of ARMS subjects had a comorbid axis I diagnosis in addition to the "at-risk" signs and symptoms. About 40% of ARMS subjects had a comorbid diagnosis of depressive disorder while anxiety disorders were less frequent (8%). The meta-analysis conducted in 1683 high-risk subjects confirmed that baseline prevalence of comorbid depressive and anxiety disorders is respectively 41% and 15%. At a psychopathological level, comorbid diagnoses of anxiety or depression were associated with higher suicidality or self-harm behaviors, disorganized/odd/stigmatizing behavior, and avolition/apathy. Comorbid anxiety and depressive diagnoses were also associated with impaired global functioning but had no effect on risk of transition to frank psychosis. Meta-regression analyses confirmed no effect of baseline anxiety and/or depressive comorbid diagnoses on transition to psychosis.

CONCLUSIONS

The ARMS patients are characterized by high prevalence of anxiety and depressive disorders in addition to their attenuated psychotic symptoms. These symptoms may reflect core emotional dysregulation processes and delusional mood in prodromal psychosis. Anxiety and depressive symptoms are likely to impact the ongoing psychopathology, the global functioning, and the overall longitudinal outcome of these patients.

Lessons learned from the psychosis high-risk state: towards a general staging model of prodromal intervention

BACKGROUND

The past two decades have seen exponential clinical and research interest in help-seeking individuals presenting with potentially prodromal symptoms for psychosis. However, the epidemiological validity of this paradigm has been neglected, limiting future advancements in the field.

METHOD

We undertook a critical review of core epidemiological issues underlying the clinical high-risk (HR) state for psychosis and which model of prodromal intervention is best suited for mental health.

RESULTS

The HR state for psychosis model needs refining, to bring together population-based findings of high levels of psychotic experiences (PEs) and clinical expression of risk. Traditionally, outcome has been attributed to 'HR criteria' alone rather than taking into account sampling strategies. Furthermore, the exclusive focus on variably defined 'transition' obscures true variation in the slow and non-linear progression across stages of psychopathology. Finally, the outcome from HR states is variable, indicating that the underlying paradigm of 'schizophrenia light progressing to schizophrenia' is inadequate.

CONCLUSIONS

In the general population, mixed and non-specific expression of psychosis, depression, anxiety and subthreshold mania is common and mostly transitory. When combined with distress, it may be considered as the first, diagnostically neutral stage of potentially more severe psychopathology, which only later may acquire a degree of diagnostic specificity and possible relative resistance to treatment. Therefore, rather than creating silos of per-disorder ultra-HR syndromes, an early intervention focus on the broad syndrome of early mental distress, requiring phase-specific interventions, may be more profitable.

Striatal abnormalities and spontaneous dyskinesias in non-clinical psychosis

BACKGROUND

Accumulating evidence suggests that individuals experiencing non-clinical psychosis (NCP) represent a critical group for improving understanding of etiological factors underlying the broader psychosis continuum. Although a wealth of evidence supports widespread neural dysfunction in formal psychosis, there has been little empirical evidence to inform our understanding of putative vulnerability markers or brain structure in NCP. In this study, we examined the neural correlates of spontaneous movement abnormalities, a biomarker previously detected in NCP that is linked to abnormalities in the striatal dopamine.

METHODS

We screened a total of 1285 adolescents/young adults, and those scoring in the upper 15th percentile on a NCP scale were invited to participate; 20 of those invited agreed and these individuals were matched with healthy controls. Participants were administered a structural scan, clinical interviews, and an instrumental motor assessment.

RESULTS

The NCP group showed elevated force variability and smaller putamen (but not caudate), and there was a significant relationship between motor dysfunction and striatal abnormalities for the sample. Elevated force variability was associated with both higher positive and negative symptoms, and there was a strong trend (p=.06) to suggest that smaller left putamen volumes were associated with elevated positive symptoms.

CONCLUSIONS

The results are among the first to suggest an association between neural structure and a risk marker in NCP. Findings indicate that vulnerabilities seen in schizophrenia also characterize the lower end of the psychosis spectrum.

Current paranoid thinking in patients with delusions: the presence of cognitive-affective biases

BACKGROUND

There has been renewed interest in the influence of affect on psychosis. Psychological research on persecutory delusions ascribes a prominent role to cognitive processes related to negative affect: anxiety leads to the anticipation of threat within paranoia; depressive negative ideas about the self create a sense of vulnerability in which paranoid thoughts flourish; and self-consciousness enhances feelings of the self as a target. The objective of this study was to examine such affective processes in relation to state paranoia in patients with delusions.

METHODS

130 patients with delusions in the context of a nonaffective psychosis diagnosis (predominately schizophrenia) were assessed for contemporaneous levels of persecutory ideation on 5 visual analog scales. Measures were taken of anxiety, depression, threat anticipation, interpretation of ambiguity, self-focus, and negative ideas about the self.

RESULTS

Of the patients, 85% report paranoid thinking at testing. Symptoms of anxiety and depression were highly prevalent. Current paranoid thinking was associated with anxiety, depression, greater anticipation of threat events, negative interpretations of ambiguous events, a self-focused cognitive style, and negative ideas about the self.

CONCLUSIONS

The study provides a clear demonstration that a range of emotion-related cognitive biases, each of which could plausibly maintain delusions, are associated with current paranoid thinking in patients with psychosis. We identified biases both in the contents of cognition and in the processing of information. Links between affect and psychosis are central to the understanding of schizophrenia. We conclude that treatment of emotional dysfunction should lead to reductions in current psychotic experiences.

The past and future of delusions research: from the inexplicable to the treatable

BACKGROUND

Problems with the diagnosis and treatment of schizophrenia have led for a call to change strategy and focus on individual psychotic experiences. In recent years, research on delusions has led the way.

AIMS

To update our 1999 review of almost 40 studies on delusions.

METHOD

A systematic literature search was conducted of reasoning and affective processes related to delusions.

RESULTS

Over 200 studies were identified. The presence of 'jumping to conclusions' in individuals with delusions has been substantiated, the theory of mind account has not stood up to subsequent testing, and there is a promising new focus on the ways that affective processes contribute to delusional experience.

CONCLUSIONS

Theoretical work rendering delusions understandable can be translated into treatment; future clinical trials should focus on individual psychotic experiences as outcomes.

Moving beyond transition outcomes: meta-analysis of remission rates in individuals at high clinical risk for psychosis

Recent evidence suggests that transition risks from initial clinical high risk (CHR) status to psychosis are decreasing. The role played by remission in this context is mostly unknown. The present study addresses this issue by means of a meta-analysis including eight relevant studies published up to January 2012 that reported remission rates from an initial CHR status. The primary effect size measure was the longitudinal proportion of remissions compared to non-remission in subjects with a baseline CHR state. Random effect models were employed to address the high heterogeneity across studies included. To assess the robustness of the results, we performed sensitivity analyses by sequentially removing each study and rerunning the analysis. Of 773 subjects who met initial CHR criteria, 73% did not convert to psychosis along a 2-year follow. Of these, about 46% fully remitted from the baseline attenuated psychotic symptoms, as evaluated on the psychometric measures usually employed by prodromal services. The corresponding clinical remission was estimated as high as 35% of the baseline CHR sample. The CHR state is associated with a significant proportion of remitting subjects that can be accounted by the effective treatments received, a lead time bias, a dilution effect, a comorbid effect of other psychiatric diagnoses.

Prevalence of psychotic symptoms in those with melancholic and nonmelancholic depression

The best classification of depressive disorders is still to be established. A melancholic subtype has a lengthy history, and recent research demonstrates its relevance. This study compares the prevalence of psychotic symptoms in nonmelancholic and melancholic depression and assesses whether there is a dimensional pattern in the severity of symptoms among the subtypes. Patients with unipolar depression were assessed for melancholic status, psychotic symptoms, and severity of depression. The diagnosis of melancholia was made by both Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), criteria and CORE measure. The DSM criteria assigned a much higher percentage of patients as melancholics (67.4%) than did the CORE (24.9%). Prevalence of psychosis was distinctly higher in the melancholics. Symptoms severity was higher among the melancholics when compared with the nonmelancholics. The presence of psychotic symptoms was not associated with an increase in the intensity of depressive symptoms. Psychotic symptoms are more frequently associated with the melancholic subtype of depression. This suggests clinical contiguity between the melancholic and psychotic subtypes and the clinical relevance of identifying melancholia.

Diagnosis and evaluation of hallucinations and other psychotic symptoms in children and adolescents

Recognizing positive psychotic symptoms and their diagnostic context in youth is challenging. A large minority say they "hear things others do not hear," though they seldom present with complaints of hallucinations or delusions. Few have schizophrenia spectrum disorder, but many have other psychiatric disorders. Frequently, they have psychotic symptoms for an extended period before diagnosis. Clinicians should understand psychotic symptoms and their differential diagnoses. This article reviews the epidemiology, associated diagnoses, and prognosis of hallucinations and delusions in youth. Strategies for optimizing the clinical diagnostic interview, appropriate laboratory tests, indications for psychological testing, and rating scales are reviewed.

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.

Prenatal vitamin D status and risk of psychotic experiences at age 18years-a longitudinal birth cohort

BACKGROUND

Low early life vitamin D status is associated with an increased risk of schizophrenia and psychotic experiences. Here we examine if maternal pregnancy vitamin D concentrations are associated with offspring psychotic experiences as young adults.

METHODS

A community sample of 2047 participants was investigated. Maternal prenatal 25 hydroxyvitamin D (25(OH)D) concentrations were assessed with tandem mass spectroscopy. Psychotic experiences were assessed at age 18years using a semi-structured clinical interview.

RESULTS

177 cohort members reported suspected or definite psychotic experiences, There was no evidence of an association between maternal 25(OH)D concentrations as quartiles (p=0.85 hypothesis test of general association versus no association across the quartiles) or as a continuous variable (p=0.89) versus experience of suspected and definite psychotic experiences at 18years. Within the cohort, only 29 subjects met criteria for a psychotic disorder at age 18. Based on this sample, there was no significant association between maternal 25(OH)D and psychotic disorder at 18years.

DISCUSSION

Maternal vitamin D levels were not associated with risk of psychotic experiences nor psychotic disorders in this birth cohort.

The association between adult attachment style and delusional-like experiences in a community sample of women

Community-based surveys have found that many otherwise well individuals endorse delusional-like experiences (DLEs). There is extensive literature that describes the demographic and psychosocial correlates of DLE; however, we know little about the association between DLE and attachment style. The association between DLEs (assessed by the Peters Delusional Inventory [PDI]) and interpersonal relationship style (as assessed by the Adult Attachment Questionnaire and the Dyadic Adjustment Scale) was examined in 3360 women. When adjusted for the presence of depressive and anxiety symptoms, high scores on the PDI (lowest versus highest quartiles) were associated with a) difficulties in adult attachment style particularly in the discomfort with closeness and preoccupation with relationships subscales and b) conflictual dyadic adjustment (adjusted odds ratios and 95% confidence intervals, 2.43 and 1.94-3.04, 2.50 and 1.99-3.14, and 2.90 and 1.38-6.06, respectively). The association between adult attachment style and DLE provides new clues into the causal pathway underpinning these common experiences.

Mechanisms Underlying Auditory Hallucinations-Understanding Perception without Stimulus

Auditory verbal hallucinations (AVH) are a common phenomenon, occurring in the “healthy” population as well as in several mental illnesses, most notably schizophrenia. Current thinking supports a spectrum conceptualisation of AVH: several neurocognitive hypotheses of AVH have been proposed, including the “feed-forward” model of failure to provide appropriate information to somatosensory cortices so that stimuli appear unbidden, and an “aberrant memory model” implicating deficient memory processes. Neuroimaging and connectivity studies are in broad agreement with these with a general dysconnectivity between frontotemporal regions involved in language, memory and salience properties. Disappointingly many AVH remain resistant to standard treatments and persist for many years. There is a need to develop novel therapies to augment existing pharmacological and psychological therapies: transcranial magnetic stimulation has emerged as a potential treatment, though more recent clinical data has been less encouraging. Our understanding of AVH remains incomplete though much progress has been made in recent years. We herein provide a broad overview and review of this.

Child literacy and psychotic experiences in early adolescence: findings from the ALSPAC study

The aim of this study was to use prospective data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine the differences in literacy skills in children who later completed the psychotic like symptoms (PLIKS) interview at 12 years of age. We further examined the association between literacy skills over time in relation to the likelihood of reporting psychotic experiences (PEs). This study examined data from n=6790 children from the ALSPAC cohort who participated in the PLIKS semi-structured interview. Literacy skills such as spelling, basic real and non-real word reading, and reading skills and comprehension were assessed by an ALSPAC spelling task, Wechsler Objective Reading Dimension, and the revised Neale Analysis of Reading Ability (NARA II) respectively. Relative to the group unaffected by PEs, we found a lower performance in all measurements of child literacy skills in those with suspected or definite PEs. The majority of these differences persisted after adjusting for a range of covariates. In addition, both a consistently low pattern of performance and a decline were associated with suspected or definite PEs. Implications for preventative intervention models focussed on children at risk of developing psychotic disorders are discussed within the context of speech and language development.

Family history of schizophrenia as a risk factor for axis I psychiatric conditions

People with first-degree relatives with schizophrenia are at an elevated risk of developing the disorder themselves. High rates of psychotic symptoms in non-psychotic disorders, high rates of comorbidity in psychotic disorders, and diversity of outcomes following psychosis-risk states together suggest that this vulnerability may be for psychiatric conditions in general, not limited to schizophrenia. In this study, data from the National Survey of American Life (NSAL) were used to examine the association between having a first-degree relative with schizophrenia and the lifetime development of a range of non-psychotic axis I psychiatric disorders using adjusted odds ratios. Having a relative with schizophrenia was associated with increased risk for most non-psychotic psychiatric conditions examined, including those expected to be associated with schizophrenia (affective, anxiety, and substance use disorders) and those not expected (bulimia, disorders of childhood onset), excluding respondents with lifetime psychotic symptoms and controlling for demographic factors. Family history of schizophrenia among this predominantly African-American and Afro-Caribbean sample appears to be a risk factor for a range of axis I diagnoses, supporting a continuous rather than categorical nature of psychiatric vulnerability. Future studies should examine whether these associations are due to genetic or environmental factors, or both.

Prevalence of attenuated psychotic symptoms and their relationship with DSM-IV diagnoses in a general psychiatric outpatient clinic

OBJECTIVE

Attenuated psychosis syndrome (APS) is being proposed for inclusion in Section III of DSM-5 for those impaired by subthreshold psychotic symptoms that are not better accounted for by another diagnosis and not meeting criteria for a psychotic disorder. The rationale is to identify patients who are at high risk for transition to a psychotic disorder in the near future. However, the potential impact of using this new diagnosis in routine clinical practice settings has not been carefully examined.

METHOD

As part of the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, a treatment-seeking psychiatric outpatient sample (n = 1,257) recruited from June 1997 to June 2002 completed a self-report measure of psychiatric symptoms and afterward were administered structured clinical interviews. For the current post hoc study, we investigated the prevalence rate of endorsing attenuated psychotic experiences to identify patients who could potentially meet criteria for APS.

RESULTS

After the exclusion of those with lifetime DSM-IV psychotic disorders, psychotic experiences remained highly prevalent in the sample (28% reported at least 1 psychotic experience during the past 2 weeks), and rates were similar across all major DSM-IV diagnostic categories. Only 1 patient (0.08%) reported psychotic experiences but did not meet criteria for another current DSM disorder; however, this individual endorsed other nonpsychotic symptoms of greater severity. Psychotic experience endorsement was positively correlated with nearly all other nonpsychotic symptom domains, and multivariate analysis showed that general clinical severity predicted endorsement of psychotic experiences (P values < .001).

CONCLUSIONS

We could not identify any patients who clearly met criteria for APS alone in our sample. Psychotic experiences appear to be common in outpatients and represent nonspecific indicators of psychopathology. Diagnosing APS in the community could result in high rates of false-positives or high rates of APS "comorbidity" with other nonpsychotic disorders, leading to the increased use of antipsychotic medications without clear need. Therefore, the clinical utility of adding APS to the diagnostic system remains highly questionable.

Child loss and psychosis onset: evidence for traumatic experience as an etiological factor in psychosis

Previous research suggests that trauma may contribute to psychosis onset. In this study, we examine the effect of parental loss of a child on the onset of psychotic experience using data from the National Comorbidity Survey Replication, hypothesizing that child loss will precede the onset of psychosis and will be associated with a later age of onset. We likewise tested this association for six other psychiatric conditions to demonstrate specificity for psychosis. Individuals with a psychotic disorder who had lost a child had a significantly later age of onset, particularly in males, even when controlling for demographic variables and co-occurring substance abuse and psychiatric disorders. Psychosis onset frequently occurred within a year of child loss. No associations were found between child loss and onset of other psychiatric conditions, supporting specificity of the effect on psychosis. The presented findings implicate child loss as an etiological factor in the onset of psychosis, providing converging evidence with previous studies demonstrating associations between more widely studied trauma exposures (abuse, neglect, and assault) and psychosis.

The heritability of delusional-like experiences

OBJECTIVE

Delusional-like experiences (DLE) are common in the general community and are associated with a family history of mental illness. The aim of this study was to estimate the heritability of DLE.

METHOD

The Peter's Delusional Inventory (PDI) was administered to a population-based cohort of mothers (n = 2861, aged 35-67 years) and their adult offspring (n = 3079, aged 18-23 years). Heritability of DLE was estimated from the sum scores of the 21 item PDI under the assumption that the covariance between mother-offspring scores is attributable to shared additive genetic factors.

RESULTS

The means (medians and standard deviations) for the total PDI scores for the mothers and their offspring were 3.6 (3.0, 3.0) and 5.0 (4.0, 3.5), respectively. The Pearson correlation coefficient between mother and offspring PDI scores was 0.17 (P < 0.001). The heritability was estimated to be 0.35 (standard error 0.04).

CONCLUSION

Heritable factors contribute to over a third of the variance of PDI scores in this population. In light of the association between a family history of a wide range of mental disorders and DLE, these experiences may represent a useful quantitative endophenotype for genetic studies of common mental disorders in population settings.

Emotion recognition and social/role dysfunction in non-clinical psychosis

As researchers continue to understand non-clinical psychosis (NCP-brief psychotic-like experiences occurring in 5-7% of the general population; van Os et al., 2009), it is becoming evident that functioning deficits and facial emotion recognition (FER) impairment characterize this phenomenon. However, the extent to which these domains are related remains unclear. Social/role functioning and FER were assessed in 65 adolescents/young adults exhibiting low and high-NCP. Results indicate that FER and social/role functioning deficits were present in the High-NCP group, and that the domains were associated in this group alone. Taken together, findings suggest that a core emotive deficit is tied to broader social/role dysfunction in NCP.

Preoccupation and distress are relevant dimensions in delusional beliefs

BACKGROUND AND PURPOSE

A large number of subjective experiences and beliefs with some degree of affinity with psychotic symptoms can be found in the general population. However, the appraisal of these psychotic-like experiences in terms of associated distress, raised preoccupation, and the conviction with which the experience is held can be more discriminative in distinguishing people in need for care from those who simply hold unusual or uncommon beliefs because of cultural reasons.

METHOD

In this study, 81 patients with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia or an affective disorder with psychotic features were compared on the Peters et al Delusions Inventory (PDI) to 210 people from the same local area, who had never received a formal diagnosis of a mental disorder.

RESULTS

Patients scored higher than controls on the PDI total score and on its distress, preoccupation, and conviction subscales. A stepwise logistic regression model showed PDI-preoccupation (odds ratio, 2.46; 95% confidence interval, 1.52-3.98) and, marginally, PDI-distress (odds ratio = 1.58; 95% confidence interval, 0.93-2.58) adding discriminative power to PDI total score in distinguishing patients from controls.

CONCLUSIONS

The evaluation of the severity of delusion-like experiences and beliefs is important in discriminating patients diagnosed with psychosis from people who are not in need of care.

Dermatoglyphic asymmetries and fronto-striatal dysfunction in young adults reporting non-clinical psychosis

OBJECTIVE

Growing evidence indicates that non-clinical psychotic-like experiences occur in otherwise healthy individuals, suggesting that psychosis may occur on a continuum. However, little is known about how the diathesis for formal psychosis maps on to individuals at the non-clinical side of this continuum. Our current understanding of the pathophysiology of schizophrenia implicates certain key factors such as early developmental abnormalities and fronto-striatal dysfunction. To date, no studies have examined these core factors in the context of non-clinical psychosis.

METHOD

A total of 221 young adults were assessed for distressing attenuated positive symptoms (DAPS), dermatoglyphic asymmetries (a marker of early developmental insult), and procedural memory (a proxy for fronto-striatal function).

RESULTS

Participants reporting DAPS (n = 16; 7.2%) and no-DAPS (n = 205; 92.7%) were split into two groups. The DAPS group showed significantly elevated depression, elevated dermatoglyphic asymmetries, and a pattern of procedural learning consistent with other studies with formally psychotic patients.

CONCLUSION

The results indicate that the non-clinical side of the psychosis continuum also shares key vulnerability factors implicated in schizophrenia, suggesting that both early developmental disruption and abnormalities in fronto-striatal function are core aspects underlying the disorder.

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.

Trajectories of change in self-reported psychotic-like experiences in childhood and adolescence

BACKGROUND

Psychotic-like experiences (PLEs) during adolescence are not uncommon and potentially represent a clinical and public health concern. A greater understanding of their aetiology and patterns of change over time is needed. We aimed to describe trajectories of PLEs during adolescence, and examine their association with characteristics earlier during development.

METHOD

This was a cohort study of 7387 adolescents from the ALSPAC birth cohort who completed self-reported questionnaires about PLEs at 4 time points over a five-year period (ages 11.5-16.5years). Association between childhood characteristics and latent class membership was examined.

RESULTS

The proportion of children reporting PLEs declined with age. Individuals within decreasing (1.7%), intermittent (16.8%), and persistent (0.9%) PLEs trajectories were more likely to come from adverse backgrounds and have disturbed childhood development compared to the low PLE (80.6%) class. Persistent-class individuals scored highest on most measures though no measure clearly distinguished between persistent, intermittent and decreasing groups.

CONCLUSIONS

A number of early life characteristics and markers of childhood emotional and behavioural development are associated with trajectories of PLEs during adolescence. Despite the increase in cost and time required to collect data at repeated intervals, studies of trajectories are likely to have greater potential for predicting transition into clinical disorder at an earlier stage.

The psychometric properties of the Peters et al. delusions inventory (PDI) in Taiwan: reliability, validity, and utility

PURPOSE

The Peters et al. Delusions Inventory (PDI) is a commonly used instrument to measure delusion proneness in the general population and includes dimensions that measure distress, preoccupation, and conviction of unusual beliefs. This self-report scale has already been translated into several languages. However, there has not been a validated Taiwanese version previously reported. The aims of the present study were to translate and test the cross-cultural reliability and validity of the PDI in Taiwanese as well as to establish its sensitivity, specificity, and discriminative validity.

METHODS

We administered the questionnaire to a consecutive sample of 253 participants with (n = 154; clinical group including schizophrenia and affective psychosis) or without psychotic disorders (n = 99; non-clinical group). In addition to the Taiwanese version of the PDI (PDI-T), the Taiwanese version of the Brief Psychiatric Symptom Rating Scale (BSRS) was used to measure the severity of psychopathology. We tested the psychometric properties of the PDI-T, including its construct validity, internal consistency, test-retest reliability, concurrent, and discriminative validity.

RESULTS

Overall, the PDI-T showed good construct validity, internal consistency, and stability over time, and it was significantly correlated with the BSRS subscales of psychotic symptoms. The convergent and discriminative validity was satisfactory. The area under the receiver operating characteristic curve of the PDI-T was 0.752. This research found that the most appropriate PDI-T yes/no cut-off scores for determining the absence and presence of delusion proneness were 5 and 13.

CONCLUSIONS

The PDI is a reliable and valid instrument for measuring the dimensionality of delusion proneness and appears to complement subclinical psychosis assessment scales for both epidemiological and clinical research in Taiwan.

Childhood cognitive function and adult psychopathology: associations with psychotic and non-psychotic symptoms in the general population

BACKGROUND

Lower cognitive ability in childhood is associated with increased risk of future schizophrenia, but its relationship with adult psychotic-like experiences and other psychopathology is less understood.

AIMS

To investigate whether this childhood risk factor is shared with adult subclinical psychiatric phenotypes including psychotic-like experiences and general psychiatric morbidity.

METHOD

A population-based sample of participants born in Great Britain during 1 week in March 1946 was contacted up to 20 times between ages 6 weeks and 53 years. Cognition was assessed at ages 8, 11 and 15 years using a composite of age-appropriate verbal and non-verbal cognitive tests. At age 53 years, psychotic-like experiences were self-reported by 2918 participants using four items from the Psychosis Screening Questionnaire and general psychiatric morbidity was assessed using the scaled version of the General Health Questionnaire (GHQ-28).

RESULTS

Psychotic-like experiences were reported by 22% of participants, and were highly comorbid with other psychopathology. Their presence in adults was significantly associated with poorer childhood cognitive test scores at ages 8 and 15 years, and marginally so at age 11 years. In contrast, high GHQ scores were not associated with poorer childhood cognition after adjustment for the presence of psychotic-like experiences.

CONCLUSIONS

Psychotic and non-psychotic psychopathologic symptoms are highly comorbid in the general population. Lower childhood cognitive ability is a risk factor for psychotic-like experiences in mid-life; these phenomena may be one end of a continuum of phenotypic expression driven by variation in early neurodevelopment.

Psychotic symptoms in young people without psychotic illness: mechanisms and meaning

Psychotic symptoms are common in the general population. There is evidence for common mechanisms underlying such symptoms in health and illness (such as the functional role of mesocorticostriatal circuitry in error-dependent learning) and differentiating factors (relating to non-psychotic features of psychotic illness and to social and emotional aspects of psychotic symptoms). Clinicians should be aware that psychotic symptoms in young people are more often associated with common mental disorders such as depression and anxiety than with severe psychotic illness.

Clinicopathological significance of psychotic experiences in non-psychotic young people: evidence from four population-based studies

BACKGROUND

Epidemiological research has shown that hallucinations and delusions, the classic symptoms of psychosis, are far more prevalent in the population than actual psychotic disorder. These symptoms are especially prevalent in childhood and adolescence. Longitudinal research has demonstrated that psychotic symptoms in adolescence increase the risk of psychotic disorder in adulthood. There has been a lack of research, however, on the immediate clinicopathological significance of psychotic symptoms in adolescence.

AIMS

To investigate the relationship between psychotic symptoms and non-psychotic psychopathology in community samples of adolescents in terms of prevalence, co-occurring disorders, comorbid (multiple) psychopathology and variation across early v. middle adolescence.

METHOD

Data from four population studies were used: two early adolescence studies (ages 11-13 years) and two mid-adolescence studies (ages 13-16 years). Studies 1 and 2 involved school-based surveys of 2243 children aged 11-16 years for psychotic symptoms and for emotional and behavioural symptoms of psychopathology. Studies 3 and 4 involved in-depth diagnostic interview assessments of psychotic symptoms and lifetime psychiatric disorders in community samples of 423 children aged 11-15 years.

RESULTS

Younger adolescents had a higher prevalence (21-23%) of psychotic symptoms than older adolescents (7%). In both age groups the majority of adolescents who reported psychotic symptoms had at least one diagnosable non-psychotic psychiatric disorder, although associations with psychopathology increased with age: nearly 80% of the mid-adolescence sample who reported psychotic symptoms had at least one diagnosis, compared with 57% of the early adolescence sample. Adolescents who reported psychotic symptoms were at particularly high risk of having multiple co-occurring diagnoses.

CONCLUSIONS

Psychotic symptoms are important risk markers for a wide range of non-psychotic psychopathological disorders, in particular for severe psychopathology characterised by multiple co-occurring diagnoses. These symptoms should be carefully assessed in all patients.

Social support and delusional-like experiences: a nationwide population-based study

BACKGROUND

Population-based studies have identified that delusional-like experiences (DLEs) are common in the general population. While there is a large literature exploring the relationship between poor social support and risk of mental illness, there is a lack of empirical data examining the association of poor social support and DLEs. The aim of the study was to explore the association between social support and DLEs using a large, nationally representative community sample.

METHODS

Subjects were drawn from a national multistage probability survey of 8841 adults aged between 16 and 85 years. The Composite International Diagnostic Interview was used to identify DLEs, common psychiatric disorders and physical disorders. Eight questions assessed various aspects of social support with spouse/partners and other family and friends. We examined the relationship between DLEs and social support using logistic regression, adjusting for potential confounding factors.

RESULTS

Of the sample, 8.4% (n = 776) positively endorsed one or more DLEs. Individuals who (a) had the least contact with friends, or (b) could not rely on or confide in spouse/partner, family or friends were significantly more likely to endorse DLEs. The associations remained significant after adjusting for a range of potential confounding factors.

CONCLUSIONS

DLEs are associated with impoverished social support in the general population. While we cannot exclude the possibility that the presence of isolated DLEs results in a reduction of social support, we speculate that poor social support may contribute in a causal fashion to the risk of DLEs.

Anxiety and depressive disorders are associated with delusional-like experiences: a replication study based on a National Survey of Mental Health and Wellbeing

OBJECTIVES

There is growing evidence that delusional-like experiences (DLE) are associated with common mental disorders. In particular, a National Mental Health Survey conducted in Australia during 2007 reported an association between DLE and both anxiety disorder and major depressive disorder (MDD). However, the previous study did not examine this association with respect to subtypes of anxiety disorder nor with severity of MDD. The aim of this study was to examine the associations between DLE and both anxiety disorder and MDD in more detail based on an independent population sample.

DESIGN

Cross-sectional study.

SETTING

Subjects were drawn from the Australian Survey of Mental Health and Wellbeing 1997 using a stratified multistage area sampling of persons living in private dwellings in all States and Territories of Australia.

PARTICIPANTS

Approximately 13 600 private dwellings were initially selected with one person aged 18 years or older from each dwelling invited to participate. In total, 10 641 individuals participated in the survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

The Composite International Diagnostic Interview was used to identify individuals with DLE and Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition (DSM IV) lifetime diagnoses of anxiety disorders and MDD. The influence of various anxiety disorders and MDD on DLE was assessed with logistic regression.

RESULTS

Having a lifetime diagnosis of either any anxiety disorder or MDD was significantly associated with the endorsement of DLE. The association was found for each of the main anxiety disorders when examined separately. There was a dose-response relationship between increasing severity of MDD and higher odds of DLE endorsement.

CONCLUSIONS

DLE are associated with a wide range of anxiety disorders and are more prevalent in those with MDD. Understanding the relationship between DLE, anxiety disorders and depression may provide insights into shared pathways that underpin both psychotic disorders and common mental disorders.

Early detection and intervention evaluation for people at risk of psychosis: multisite randomised controlled trial

OBJECTIVE

To determine whether cognitive therapy is effective in preventing the worsening of emerging psychotic symptoms experienced by help seeking young people deemed to be at risk for serious conditions such as schizophrenia.

DESIGN

Multisite single blind randomised controlled trial.

SETTING

Diverse services at five UK sites.

PARTICIPANTS

288 participants aged 14-35 years (mean 20.74, SD 4.34 years) at high risk of psychosis: 144 were assigned to cognitive therapy plus monitoring of mental state and 144 to monitoring of mental state only. Participants were followed-up for a minimum of 12 months and a maximum of 24 months.

INTERVENTION

Cognitive therapy (up to 26 (mean 9.1) sessions over six months) plus monitoring of mental state compared with monitoring of mental state only.

MAIN OUTCOME MEASURES

Primary outcome was scores on the comprehensive assessment of at risk mental states (CAARMS), which provides a dichotomous transition to psychosis score and ordinal scores for severity of psychotic symptoms and distress. Secondary outcomes included emotional dysfunction and quality of life.

RESULTS

Transition to psychosis based on intention to treat was analysed using discrete time survival models. Overall, the prevalence of transition was lower than expected (23/288; 8%), with no significant difference between the two groups (proportional odds ratio 0.73, 95% confidence interval 0.32 to 1.68). Changes in severity of symptoms and distress, as well as secondary outcomes, were analysed using random effects regression (analysis of covariance) adjusted for site and baseline symptoms. Distress from psychotic symptoms did not differ (estimated difference at 12 months -3.00, 95% confidence interval -6.95 to 0.94) but their severity was significantly reduced in the group assigned to cognitive therapy (estimated between group effect size at 12 months -3.67, -6.71 to -0.64, P=0.018).

CONCLUSIONS

Cognitive therapy plus monitoring did not significantly reduce transition to psychosis or symptom related distress but reduced the severity of psychotic symptoms in young people at high risk. Most participants in both groups improved over time. The results have important implications for the at risk mental state concept.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN56283883.

Evidence that psychotic symptoms are prevalent in disorders of anxiety and depression, impacting on illness onset, risk, and severity--implications for diagnosis and ultra-high risk research

BACKGROUND

It is commonly assumed that there are clear lines of demarcation between anxiety and depressive disorders on the one hand and psychosis on the other. Recent evidence, however, suggests that this principle may be in need of updating.

METHODS

Depressive and/or anxiety disorders, with no previous history of psychotic disorder, were examined for the presence of psychotic symptoms in a representative community sample of adolescents and young adults (Early Developmental Stages of Psychopathology study; n = 3021). Associations and consequences of psychotic symptomatology in the course of these disorders were examined in terms of demographic distribution, illness severity, onset of service use, and risk factors.

RESULTS

Around 27% of those with disorders of anxiety and depression displayed one or more psychotic symptoms, vs 14% in those without these disorders (OR 2.23, 95% CI 1.89-2.66, P < .001). Presence as compared with nonpresence of psychotic symptomatology was associated with younger age (P < .0001), male sex (P < .0058), and poorer illness course (P < .0002). In addition, there was greater persistence of schizotypal (P < .0001) and negative symptoms (P < .0170), more observable illness behavior (P < .0001), greater likelihood of service use (P < .0069), as well as more evidence of familial liability for mental illness (P < .0100), exposure to trauma (P < .0150), recent and more distant life events (P < .0006-.0244), cannabis use (P < .0009), and any drug use (P < .0008).

CONCLUSION

Copresence of psychotic symptomatology in disorders of anxiety and depression is common and a functionally and etiologically highly relevant feature, reinforcing the view that psychopathology is represented by a network or overlapping and reciprocally impacting dimensional liabilities.

Evidence that genes for depression impact on the pathway from trauma to psychotic-like symptoms by occasioning emotional dysregulation

BACKGROUND

Genes for depression may act by making individuals more sensitive to childhood trauma. Given that childhood adversity is a risk factor for adult psychosis and symptoms of depression and psychosis tend to cluster within individuals and families, the aim was to examine whether the association between childhood adversity and psychotic-like symptoms is moderated by genetic liability for depression. A secondary aim was to determine to what degree a depression-related increase in stress sensitivity or depressive symptoms themselves occasioned the moderating effect.

METHOD

Female twins (n=508) completed both prospective and retrospective questionnaires regarding childhood adversity [the Symptom Checklist-90 - Revised (SCL-90-R) and SCID-I (psychotic symptoms)] and psychotic trait liability [the Community Assessment of Psychic Experiences (CAPE)]. Stress sensitivity was indexed by appraisals of event-related stress and negative affect (NA) in the flow of daily life, assessed with momentary assessment technology for five consecutive days. Multilevel regression analyses were used to examine moderation of childhood adversity by genetic liability for depression in the prediction of follow-up psychotic experiences.

RESULTS

The effect of childhood adversity was significantly moderated by genetic vulnerability for depression in the model of both follow-up psychotic experiences (SCL-90-R) and follow-up psychotic trait liability (CAPE). The moderation by genetic liability was mediated by depressive experience but not by stress sensitivity.

CONCLUSIONS

Genetic liability for depression may potentiate the pathway from childhood adversity to psychotic-like symptoms through dysfunctional emotional processing of anomalous experiences associated with childhood trauma.

The association between delusional-like experiences, and tobacco, alcohol or cannabis use: a nationwide population-based survey

BACKGROUND

Previous population-based studies have found that delusional-like experiences (DLE) are prevalent in the community, and are associated with a wide range of mental health disorders including substance use. The aim of the study was to explore the association between DLE and three commonly used substances--tobacco, alcohol and cannabis.

METHODS

Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007. The Composite International Diagnostic Interview was used to identify DLE, common psychiatric disorders, and substance use. We examined the relationship between the variables of interest using logistic regression, adjusting for potential confounding factors.

RESULTS

Of 8,773 participants, 8.4% (n=776) subjects endorsed one or more DLE. With respect to tobacco use, compared to nonusers, DLE were more common in those who (a) had daily use, (b) commenced usage aged 15 years or less, and (c) those who smoked heavily (23 or more cigarettes per day). Participants with cannabis use disorders were more likely to endorse DLE; this association was most prominent in those with an onset of 16 years or younger. In contrast, the pattern of association between DLE versus alcohol use or dependence was less consistent, however those with early onset alcohol use disorders were more likely to endorse DLE probe items.

CONCLUSIONS

While cannabis use disorders have been previously linked with DLE, our findings linking alcohol and tobacco use and DLE suggest that the influence of these substances on psychosis-related outcomes warrants closer scrutiny in longitudinal prospective studies.

Socio-economic disadvantage and delusional-like experiences: a nationwide population-based study

PURPOSE

Delusional-like experiences (DLE) have been associated with low income, suggesting that more broadly defined socio-economic disadvantage may be associated with these experiences. We had the opportunity to explore the association between DLE and both individual- and area-level measures of socio-economic disadvantage.

METHOD

Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007. The Composite International Diagnostic Interview was used to identify DLE, common psychiatric disorders, and physical disorders. Individual-level and area-level socio-economic disadvantage measures were available based on variables including income, educational attainment, employment status, and housing. We examined the relationship between the variables of interest using logistic regression, adjusting for potential confounding factors.

RESULTS

Of the 8773 subjects, 8.4% (n=776) positively endorsed one or more DLE. DLE screen items were more likely to be endorsed by those who were (a) younger, (b) never married, or widowed, separated or divorced status, (c) migrants, or (d) living in rented houses. There were significant associations between socio-economic disadvantage and increased DLE endorsement, and this was found for both individual-level and area-level measures of socio-economic disadvantage. In general, the associations remained significant after adjusting for a range of potential confounding factors and in planned sensitivity analyses.

CONCLUSIONS

DLE are associated with socio-economic disadvantage in the general population. We speculate that the link between socio-economic disadvantage and DLE may be mediated by psychosocial stress and general psychological distress.

The association between delusional-like experiences and suicidal thoughts and behaviour

BACKGROUND

Delusional-like experiences (DLEs) are common in the general population. Whilst it is well known that psychotic disorders increase the risk of suicide, it is unclear if DLEs are also associated with suicidal thoughts and behaviour. This study aims to explore these variables in a large population-based sample.

METHOD

Participants were drawn from a national survey of mental health (n=8841) in Australia. The Composite International Diagnostic Interview was used to identify DLEs, psychiatric disorders, and information related to suicidal ideation, suicide plan and suicide attempts. We examined the relationship between DLEs and suicidal ideation, plans and attempts using logistic regression, adjusted for a range of potentially confounding variables.

RESULTS

8.4% of subjects endorsed one or more DLEs. 12.9% subjects reported suicidal ideation, 3.8% suicidal plans, and 3.0% a suicide attempt at some point in their lives. Those with any DLE were about two to four times as likely to report suicidal ideation, plans or attempts. There was a dose response relationship between DLEs and endorsement of suicide-related items.

CONCLUSIONS

DLEs are common in the general population and appear to be independently associated with suicidal thoughts and behaviour. DLE may provide a marker of vulnerability to suicide, and thus could be of value in future suicide prevention research.

Might the inability to feel pleasure (anhedonia) explain the symptoms of major depression and schizophrenia, including unmotivated anxiety, delusions and hallucinations?

Inability to enjoy normally pleasurable experiences (anhedonia) is a symptom common both to major depression and schizophrenia. It also regularly accompanies and follows stress, and its presence in the two mental illnesses could depend on the fact that both are facilitated and often preceded by stressful events. Anhedonia might possibly accompany stress because the loss of the pleasure of aiming for a goal and achieving it (including defending oneself and escaping from a danger) could lead to immobility, and immobility (playing dead) offers the extreme chance of safety when an animal is facing the worst possible stressful situation--being seized by a predator--as in this case any movement can further stimulate the predator's aggressiveness. Perceiving and connecting sensory information also gives pleasure, and this appears to enhance the clarity of sensations and is an important factor in learning. We propose that anhedonia, by reducing or eliminating the pleasure, might jeopardize the usual appearance of the environment, which must not only be clearly perceived but also continuously interpreted (for instance a foreshortening, or something far off seen as small, must not be seen as a real deformation; the same holds for words, where the meaning has to be grasped from the single letters, and so on). Consequently, anhedonia could in some cases make the environment's image strange, distorted and frightening, and this could cause anxiety, confusion, and give problems in contacts with people and things. As correct information about images and sounds can inhibit visual and auditory hallucinations (considering them, like delusions, as attempts to reconstruct and make sense again of a world that is becoming confused and alien), we propose that anhedonia, interfering with the correct perceiving and processing of sensations, may facilitate them.

The psychosis continuum in the general population: findings from the São Paulo Epidemiologic Catchment Area Study

The aim of the study was to examine the psychosis continuum in a Latin-American community setting. Data were from the Brazilian São Paulo Epidemiologic Catchment Area Study, a cross-sectional survey conducted in two boroughs of the city of São Paulo. The Composite International Diagnosis Interview (version 1.1) was applied to a probabilistic sample of 1,464 adults, who were interviewed in their household, in order to identify the presence of psychotic symptoms. A subsample was assessed with Schedules for Clinical Assessment in Neuropsychiatry interview. We described the occurrence of psychotic symptoms, categorized into subgroups according to their clinical impact, disability, and help-seeking behavior. The correlation of socio-demographic variables, depressive symptoms, and alcohol and substance use disorders with those psychotic subgroups was analyzed. Polychotomic logistic regression tested the associations between subgroups of psychosis (clinical and subclinical) and the correlates. Of the total sample, 38.0% presented at least one lifetime psychotic symptom, 1.9% met the criteria for an ICD-10 diagnosis of non-affective psychosis, 5.4% presented clinically relevant psychotic symptoms, and 30.7% endorsed clinically non-relevant symptoms. The most common psychotic symptom was delusion with a plausible explanation (in 18.6%). The presence of any psychiatric diagnosis was associated with the presence of psychotic symptoms (OR range, 1.9-8.9). Subclinical psychosis subgroups were found to be associated with the 18-24 year age bracket, chronic depressive mood, and alcohol use disorder. Our results support the concept of a psychosis continuum in Latin-American populations, suggesting that different risk factors influence their manifestation across the continuum.

The association between trauma and delusional-like experiences

Individuals exposed to childhood trauma are more likely to report delusional-like experiences (DLE). This study examined the association between trauma exposure and DLE in a large community sample, investigating different trauma types and age-at-first-exposure to trauma. Subjects were from the Australian National Survey of Mental Health and Wellbeing 2007. Associations between DLE and (i) exposure to different trauma types and (ii) age-at-first-exposure were assessed using logistic regression with adjustments for potential confounding factors. 8.4% of 8773 subjects reported DLE and almost 75% reported at least one traumatic event. Exposure to a traumatic event was significantly associated with more than twice the odds of delusional-like experiences and exposure to more types of trauma increased the likelihood of DLE in a dose dependent fashion. The majority of the individual trauma items were independently associated with any endorsement of DLE. First exposure of trauma in childhood, adolescence and adulthood was all associated with DLE. Further understanding of biological and cognitive pathways is required to unravel the association between trauma exposure and delusional-like experiences.

Sub-clinical psychosis symptoms in young adults are risk factors for subsequent common mental disorders

BACKGROUND

Not all persons identified in the early stages to be at risk for psychosis eventually cross the threshold for a psychotic illness. However, sub-clinical symptoms may not only indicate a specific risk but also suggest a more general, underlying psychopathology that predisposes one to various common mental disorders.

METHODS

Analyzing data from the prospective Zurich Cohort Study, we used two psychosis subscales - "schizotypal signs" and "schizophrenia nuclear symptoms" - derived from the SCL-90-R checklist that measured sub-clinical psychosis symptoms in 1979. We also assessed 10 different diagnoses of common mental disorders through seven interview waves between 1979 and 2008. This 30-year span, covering participant ages of 19/20 to 49/50, encompasses the period of highest risk for the occurrence of such disorders.

RESULTS

Both psychosis scales from 1979, but especially "schizotypal signs", were significantly correlated with most mental disorders over the subsequent test period. Higher values on both subscales were associated with an increasing number of co-occurring disorders.

CONCLUSIONS

Our data demonstrate that sub-clinical psychosis generally represents a risk factor for the development of common mental disorders and a liability for co-occurring disorders. This refers in particular to dysthymia, bipolar disorder, social phobia, and obsessive-compulsive disorder. Proneness to psychosis could signal a fundamental tendency toward common mental disorders.

A twin study of genetic and environmental determinants of abnormal persistence of psychotic experiences in young adulthood

Evidence suggests that subclinical psychotic experiences are more likely to cause transition to psychotic disorder if their expression becomes persistent. The study of longitudinal patterns of subclinical psychotic experiences may help to distinguish subgroups with transient and persistent psychotic symptoms, who may differ in risk of later psychosis. The current study investigated patterns of developmental course of subclinical psychotic experiences in a general population sample of 566 female twins, aged 18-45 years. The positive symptoms subscale of the Community Assessment of Psychic Experiences (CAPE), completed three times in 2 years, was analyzed with growth modeling. Using Latent Class Analysis, two developmental courses were distinguished: a Persistent and a Low (expression of subclinical psychotic experiences) group. The Persistent group reported significantly higher levels of depressive and negative symptoms and worse functioning in daily life. Childhood trauma (OR: 3.26, P < 0.0001) and stressful life events over the study period (OR: 3.15, P = 0.031) predicted membership of the Persistent group. Of the monozygotic (MZ) twins with their co-twin in the Persistent group, 49% also were in the Persistent group themselves (OR: 9.32, P < 0.0001), compared to only 14% in the dizygotic (DZ) co-twins (OR: 1.56, P = 0.42) (χ(2)(2) = 22.97; P < 0.001). The findings suggest that persistence of subclinical psychosis is influenced by both genetic and environmental factors, providing the possibility to study the (possibly modifiable) etiology underlying the longitudinal process of persistence of the early expression of psychosis liability.

The association between physical health and delusional-like experiences: a general population study

OBJECTIVE

Delusional-like experiences (DLE) are prevalent in the community. Recent community based studies have found that DLE are more common in those with depression and anxiety disorders, and in those with subclinical symptoms of depression and anxiety. Chronic physical disorders are associated with comorbid depression and anxiety; however, there is a lack of evidence about the association of DLE with common physical conditions. The aim of this study was to explore associations between the common physical disorders and DLE using a large population sample.

METHODS

Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007, a national household survey of 8841 residents aged between 16 and 85 years. The presence of DLE, selected common physical disorders and symptoms were assessed using a modified World Mental Health Composite International Diagnostic Interview (CIDI) schedule. We examined the relationship between DLE, and physical health-related variables using logistic regression, with adjustments for potential confounding factors.

RESULTS

Of the 8771, 776 (8.4%) subjects positively endorsed one or more DLE. Of the six physical disorders examined, only diabetes and arthritis were significantly associated with the endorsement of DLE. Of the seven broad physical symptoms explored, only hearing problems were consistently associated with DLE.

CONCLUSION

Delusional-like experiences are common in the Australian community, and are associated with selected chronic physical disorders and with impaired hearing. The direction of causality between these variables warrants closer research scrutiny.

The association between general psychological distress and delusional-like experiences: a large population-based study

BACKGROUND

Delusional-like experiences (DLE) are prevalent in the community, and are associated with the both clinical and subclinical depression and anxiety. The aim of this study was to explore the association between general psychological distress and DLE adjusting for the presence of psychiatric disorders in a large population-based sample.

METHODS

Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007 (n=8841). DLE were assessed using a modified World Mental Health Composite International Diagnostic Interview (CIDI) schedule, and psychological distress was measured using the Kessler-10 (K10) short questionnaire. We examined the relationship between DLE and quartiles of K10 scores using logistic regression, adjusting for depression and anxiety disorders, and other potential confounding factors. The analyses were also repeated in the subgroup of the sample who were free of lifetime clinical diagnoses.

RESULTS

Of the participants, 776 (8.4%) endorsed one or more DLE. Individuals with moderate and severe psychological distress were two to three times more likely to endorse DLE. The association remained significant after adjusting for potential confounding factors, and in the subgroup of the population who remained after excluding those who met criteria for lifetime diagnosis for any mental disorder.

CONCLUSION

While DLE have traditionally been associated with psychotic disorders, our results suggest that they are associated with non-specific psychological distress in otherwise-well individuals.

The 2nd Schizophrenia International Research Society Conference, 10-14 April 2010, Florence, Italy: summaries of oral sessions

The 2nd Schizophrenia International Research Society Conference, was held in Florence, Italy, April 10-15, 2010. Student travel awardees served as rapporteurs of each oral session and focused their summaries on the most significant findings that emerged from each session and the discussions that followed. The following report is a composite of these reviews. It is hoped that it will provide an overview for those who were present, but could not participate in all sessions, and those who did not have the opportunity to attend, but who would be interested in an update on current investigations ongoing in the field of schizophrenia research.