Persistence Of Psychotic Experiences Research Articles

10.G. Workshop: Investigating risk and protective factors for youth mental health using population-based datasets

Abstract Mental health problems are increasing among young people both in Ireland and worldwide and the causes of this increase are not known. This workshop will focus on large population based datasets which provide recent and comprehensive information on the mental health of young people, including the Growing Up in Ireland study, the Planet Youth study and the ALSPAC cohort. We will present recent data on prevalence of mental health disorders among adolescents and we will present data on possible risk factors and protective factors for mental health problems in youth. We will focus on the possible role played by the COVID pandemic in this observed increase. We will also present data relating to substance use including cannabis use and diet . We will explore trajectories of psychopathology between childhood and adolescence and incidence and persistence of psychotic experiences in youth. This workshop will be a chance to bring together researchers and clinicians working in this important area to discuss the issue of youth mental health which will have importance not just for Ireland but for other countries worldwide. Key messages • An increase in mental health problems among young people has been observed over recent years but the causes for this increase are not known. • There is an urgent need to identify risk and protective factors for mental health problems among youth and how these are changing over time.

Incidence and persistence of psychotic experiences among young people

Abstract Background and Hypothesis Psychotic experiences (PEs) are associated with increased risk for mental disorders, in particular persistent PEs. PEs therefore might be useful within intervention research. We sought to systematically determine the incidence and persistence of PEs in the general population. Study Design: A double-blind search of databases (Embase, Pubmed PMC, Psychinfo, Medline, and Web of Science) from inception to January 2023 and data extraction, were conducted. Study quality was assessed using the NIH assessment tool. Random effects models were conducted to calculate pooled incidence rate per personyear and proportion of persistent PEs per year. Age and study design were all examined using subgroup analyses. Demographic, risk factors, and outcomes for incidence and persistence of PEs were reported in a narrative synthesis. Results Using a double-blind screening method for abstract (k = 5763) and full text (k = 250) were screened. In total 91 samples from 71 studies were included, of which 39 were included in a meta-analysis (incidence: k = 17, n = 56 089; persistence: k = 22, n = 81 847). Incidence rate was 0.023 per person-year (95% CI [0.0129;0.0322]). That is, for every 100 people, 2 reported first onset PEs in a year. This was highest in adolescence at 5 per 100(13-17 years). The pooled persistence rate for PEs was 31.0% (95% CI [26.65,35.35]) This was highest in adolescence at 35.8%. Cannabis was particularly associated with incidence of PEs, and persistence of PEs were associated with multiple mental disorders. Conclusions Each year incidence of PEs is 2 of every 100 people, and persists each year in 31% of cases, this risk is highest in adolescents.

Incidence and Persistence of Psychotic Experiences in the General Population: Systematic Review and Meta-Analysis.

Psychotic experiences (PEs) are associated with increased risk for mental disorders, in particular persistent PEs. PEs therefore might be useful within intervention research. We sought to systematically determine the incidence and persistence of PEs in the general population. A double-blind search of databases (Embase, Pubmed PMC, Psychinfo, Medline, and Web of Science) from inception to January 2023 and data extraction, were conducted. Study quality was assessed using the NIH assessment tool. Random effects models were conducted to calculate pooled incidence rate per person-year and proportion of persistent PEs per year. Age and study design were all examined using subgroup analyses. Demographic, risk factors, and outcomes for incidence and persistence of PEs were reported in a narrative synthesis. Using a double-blind screening method for abstract (k = 5763) and full text (k = 250) were screened. In total 91 samples from 71 studies were included, of which 39 were included in a meta-analysis (incidence: k = 17, n = 56 089; persistence: k = 22, n = 81 847). Incidence rate was 0.023 per person-year (95% CI [0.0129;0.0322]). That is, for every 100 people, 2 reported first onset PEs in a year. This was highest in adolescence at 5 per 100(13-17 years). The pooled persistence rate for PEs was 31.0% (95% CI [26.65,35.35]) This was highest in adolescence at 35.8%. Cannabis was particularly associated with incidence of PEs, and persistence of PEs were associated with multiple mental disorders. Each year incidence of PEs is 2 of every 100 people, and persists each year in 31% of cases, this risk is highest in adolescents.

Prevalence, incidence, and persistence of psychotic experiences in the general population: results of a 9-year follow-up study - CORRIGENDUM.

Prevalence, incidence, and persistence of psychotic experiences in the general population: results of a 9-year follow-up study - CORRIGENDUM.

Prevalence, incidence, and persistence of psychotic experiences in the general population: results of a 9-year follow-up study.

Psychotic experiences (PEs) frequently occur and are associated with a range of negative health outcomes. Prospective studies on PEs are scarce, and to date no study investigated PE prevalence, incidence, persistence, their risk indicators, and psychiatric comorbidity, in one dataset. Furthermore, most studies are based on self-report, and it is unclear how this compares to clinical interviews. Data are used from the Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2), a psychiatric cohort study among a representative sample of adults (baseline characteristics: N = 6646; 49.6% female; 18-64 years). Results are presented for self-reported and clinically validated PEs. Associations are assessed for mental disorders, socio-demographic, vulnerability, physical health, and substance use factors. Based on self-report, at baseline 16.5% of respondents had at least one PE in their lifetime, of those, 30.1% also reported a PE at 3-year follow-up. 4.8% had a first PE at 3-year follow up. The 3-year prevalence of PE was associated with almost all studied risk indicators. Generally, the strongest associations were found for mental health disorders. Prevalence and incidence rates were two to three times higher in self-report than in clinical interview but results on associated factors were similar. Validated prevalence and incidence estimates of PE are substantially lower than self-reported figures but results on associated factors were similar. Therefore, future studies on associations of PEs can rely on relatively inexpensive self-reports of PEs. The associations between PE and mental disorders underline the importance of assessment of PE in general practice.

A 6-year follow-up study in a community-based population: Is neighbourhood-level social capital associated with the risk of emergence and persistence of psychotic experiences and transition to psychotic disorder?

Social capital is thought to represent an environmental factor associated with the risk of psychotic disorder (PD). This study aims to investigate the association between neighbourhood-level social capital and clinical transitions within the spectrum of psychosis. In total, 2175 participants, representative of a community-based population, were assessed twice (6 years apart) to determine their position within an extended psychosis spectrum: no symptoms, subclinical psychotic experiences (PE), clinical PE, PD. A variable representing change between baseline (T1) and follow-up (T2) assessment was constructed. Four dimensions of social capital (informal social control, social disorganisation, social cohesion and trust, cognitive social capital) were assessed at baseline in an independent sample, and the measures were aggregated to the neighbourhood level. Associations between the variable representing psychosis spectrum change from T1 to T2 and the social capital variables were investigated. Lower levels of neighbourhood-level social disorganisation, meaning higher levels of social capital, reduced the risk of clinical PE onset (OR 0.300; z = -2.75; p = 0.006), persistence of clinical PE (OR 0.314; z = -2.36; p = 0.018) and also the transition to PD (OR 0.136; z = -2.12; p = 0.034). The other social capital variables were not associated with changes from T1 to T2. Neighbourhood-level social disorganisation may be associated with the risk of psychosis expression. Whilst replication of this finding is required, it may point to level of social disorganisation as a public health target moderating population psychosis risk.

Precursors and correlates of transient and persistent longitudinal profiles of psychotic experiences from late childhood through early adulthood.

Psychotic experiences are reported by 5-10% of young people, although only a minority persist and develop into psychotic disorders. It is unclear what characteristics differentiate those with transient psychotic experiences from those with persistent psychotic experiences that are more likely to be of clinical relevance. To investigate how longitudinal profiles of psychotic experiences, created from assessments at three different time points, are influenced by early life and co-occurring factors. Using data from 8045 individuals from a birth cohort study, longitudinal profiles of psychotic experiences based on semi-structured interviews conducted at 12, 18 and 24 years were defined. Environmental, cognitive, psychopathological and genetic determinants of these profiles were investigated, along with concurrent changes in psychopathology and cognition. Following multiple imputations, the distribution of longitudinal profiles of psychotic experiences was none (65.7%), transient (24.1%), low-frequency persistent (8.4%) and high-frequency persistent (1.7%). Individuals with high-frequency persistent psychotic experiences were more likely to report traumatic experiences, other psychopathology, a more externalised locus of control, reduced emotional stability and conscientious personality traits in childhood, compared with those with transient psychotic experiences. These characteristics also differed between those who had any psychotic experiences and those who did not. These findings indicate that the same risk factors are associated with incidence as with persistence of psychotic experiences. Thus, it might be that the severity of exposure, rather than the presence of specific disease-modifying factors, is most likely to determine whether psychotic experiences are transient or persist, and potentially develop into a clinical disorder over time.

Treating sleep problems in young people at ultra-high-risk of psychosis: study protocol for a single-blind parallel group randomised controlled feasibility trial (SleepWell)

BackgroundEffective interventions, targeting key contributory causal factors, are needed to prevent the emergence of severe mental health problems in young people. Insomnia is a common clinical issue that is problematic...

Sleep and schizophrenia: From epiphenomenon to treatable causal target

BackgroundSleep disturbance is a common clinical issue for patients with psychosis. It has been identified as a putative causal factor in the onset and persistence of psychotic experiences (paranoia and hallucinations). Hence sleep disruption may be a potential treatment target to prevent the onset of psychosis and reduce persistent psychotic experiences. The aim of this review is to describe developments in understanding the nature, causal role, and treatment of sleep disruption in psychosis. MethodA systematic literature search was conducted to identify studies, published in the last five years, investigating subjective sleep disruption and psychotic experiences. ResultsFifty-eight papers were identified: 37 clinical and 21 non-clinical studies. The studies were correlational (n = 38; 20 clinical, 18 non-clinical), treatment (n = 7; 1 non-clinical), qualitative accounts (n = 6 clinical), prevalence estimates (n = 5 clinical), and experimental tests (n = 2 non-clinical). Insomnia (50%) and nightmare disorder (48%) are the most prevalent sleep problems found in patients. Sleep disruption predicts the onset and persistence of psychotic experiences such as paranoia and hallucinations, with negative affect identified as a partial mediator of this relationship. Patients recognise the detrimental effects of disrupted sleep and are keen for treatment. All psychological intervention studies reported large effect size improvements in sleep and there may be modest resultant improvements in psychotic experiences. ConclusionsSleep disruption is a treatable clinical problem in patients with psychosis. It is important to treat in its own right but may also lessen psychotic experiences. Research is required on how this knowledge can be implemented in clinical services.

ApoE elevation is associated with the persistence of psychotic experiences from age 12 to age 18: Evidence from the ALSPAC birth cohort

Apolipoproteins, which play important roles in lipid metabolism, innate immunity and synaptic signalling, have been implicated in first episode psychosis and schizophrenia. This is the first study to investigate plasma apolipoprotein expression in children with psychotic experiences that persist into adulthood. Here, using semi-targeted proteomic analysis we compared plasma apolipoprotein expression levels in age 12 subjects who reported psychotic experiences at both age 12 and age 18 (n = 37) with age-matched subjects who only experienced psychotic experiences (PEs) at age 12 (n = 38). Participants were recruited from the UK Avon Longitudinal Study of Parents and Children (ALSPAC) cohort who participated in psychiatric assessment interviews at ages 12 and 18. We identified apoE, a protein with significant regulatory activity on cholesterol metabolism in the brain, to be significantly up regulated (p < 0.003) in those with persistent psychotic experiences. We confirmed this finding in these samples using ELISA. Our findings indicate elevated plasma apoE in age 12 children who experience PEs is associated with persistence psychotic experiences.

Childhood trauma and adolescent psychotic experiences in a community-based cohort: The potential role of positive attributes as a protective factor

ObjectiveTo investigate how a set of positive social and personality characteristics called ‘positive attributes’ affects the emergence and persistence of Psychotic Experiences (PE) in adolescence. MethodWe used data from a community-based Brazilian High-Risk Cohort (HRC). 2511 6–12 year-old children were evaluated at baseline, and 80.05% completed a 3-year follow-up interview. At baseline, childhood trauma was assessed using parent- and self-report, and positive attributes were assessed by parent-report. Trained psychologists rated self-reported PE at both time points. Linear models evaluated the effect of childhood trauma and positive attributes on PE at follow-up. Mediation models tested i.) the indirect effect of positive attributes on the association between childhood trauma and follow-up PE and, ii.) the indirect effect of childhood trauma and positive attributes on the relationship between PE at baseline and follow-up. ResultsHigher levels of baseline PE (B = 0.157, p < .001) and higher childhood trauma (B = 0.110, p < .001) were associated with increased follow-up PE. Higher positive attributes predicted lower PE after 3 years, adjusting for the prevalence of baseline PE and childhood trauma (B = −0.042, p < .022). Positive attributes partially mediated the relationship between childhood trauma and follow-up PE. The indirect pathway of childhood trauma and positive attributes mediated the association between baseline and follow-up PE. ConclusionsHigher levels of positive social and behavioral traits in childhood may diminish the subsequent emergence of PE. As these attributes can be promoted, our findings suggest that positive attributes may represent a novel target for preventive interventions in children at risk of developing PE.

O1.1 ALTERED COMPLEMENT PATHWAY PROTEIN EXPRESSION IS ASSOCIATED WITH PSYCHOTIC EXPERIENCES AT AGE 11 WHICH PERSIST AT AGE 18

BackgroundThe identification of early biomarkers of psychotic disorder is important because early treatment is associated with improved outcome. We have previously shown that altered complement and coagulation pathway associated proteins are associated pathway with psychotic disorder at age 18. In the current study we test the hypothesis that altered complement pathway proteins are associated with persisting psychotic experiences from age 11 to age 18.MethodsThe Avon Longitudinal Study of Parents and Children (ALSPAC) is a prospective general population cohort, and a rich resource of demographic, environmental, and clinical data on the individuals involved. We studied a subsample of the cohort who participated in psychiatric assessment interviews at age 11 and 18, and who provided plasma samples at age 11. Semi-targeted proteomic profiling was used to specifically assess the complement pathway proteins in age 11 children who experienced psychotic experiences (but not disorder) at age 11 and age 18 (n=39) compared to age 11 children who only experienced psychotic experiences at age 11.Results11 of 34 proteins assessed were significantly differentially expressed at p<0.05 and of these 8 remained significant following correction for multiple comparisons. Protein changes were in keeping with increased proteins expression of most complement pathway proteins. Several protein changes represented specific replications of the changes observed in age 11 samples prior to psychotic disorder at age 18, namely increased plasminogen, complement factor H, and complement factor 1r.DiscussionOur findings implicate the blood complement system in the persistence of psychotic experiences from age 11 to age 18. Considering that psychotic experiences are predictive of many psychiatric disorders our findings implicate the complement system not just in psychotic disorders, but more broadly in the vulnerability to a range of adult psychiatric disorders.

32.4 ALTERED COMPLEMENT PATHWAY PROTEIN EXPRESSION IS ASSOCIATED WITH PSYCHOTIC EXPERIENCES AT AGE 11 WHICH PERSIST AT AGE 18

BackgroundThe identification of early biomarkers of psychotic disorder is important because early treatment is associated with improved outcome. We have previously shown that altered complement and coagulation pathway associated proteins are associated pathway with psychotic disorder at age 18. In the current study we test the hypothesis that altered complement pathway proteins are associated with persisting psychotic experiences from age 11 to age 18.MethodsThe Avon Longitudinal Study of Parents and Children (ALSPAC) is a prospective general population cohort, and a rich resource of demographic, environmental, and clinical data on the individuals involved. We studied a subsample of the cohort who participated in psychiatric assessment interviews at age 11 and 18, and who provided plasma samples at age 11. Semi-targeted proteomic profiling was used to specifically assess the complement pathway proteins in age 11 children who experienced psychotic experiences (but not disorder) at age 11 and age 18 (n=39) compared to age 11 children who only experienced psychotic experiences at age 11.Results11 of 34 proteins assessed were significantly differentially expressed at p<0.05 and of these 8 remained significant following correction for multiple comparisons. Protein changes were in keeping with increased proteins expression of most complement pathway proteins. Several protein changes represented specific replications of the changes observed in age 11 samples prior to psychotic disorder at age 18, namely increased plasminogen, complement factor H, and complement factor 1r.DiscussionOur findings implicate the blood complement system in the persistence of psychotic experiences from age 11 to age 18. Considering that psychotic experiences are predictive of many psychiatric disorders our findings implicate the complement system not just in psychotic disorders, but more broadly in the vulnerability to a range of adult psychiatric disorders.

Which social environment is more important in the persistence of psychotic experiences? Differential impact of neighbourhood and family context in a six-year longitudinal population-based cohort

Introduction Social environment may lead to emergence and persistence of psychotic experiences. Objectives Testing differential impact of social environments on emergence and persistence of subclinical psychotic experiences. Aims To assess different social environments that predicts emergence and persistence of subclinical psychotic experiences in a 6-year follow-up of a representative general population sample. Methods A longitudinal prospective cohort study (the TurkSch - The Izmir Mental Health Survey for Gene-Environment in Psychoses) was conducted with a general population sample ( n =4011) from Izmir-Turkey, who were 15-64 years of age at baseline. Sociodemographic factors, social environmental exposures (deprivation and social capital of neighbourhoods, and familial dysfunction and relationships), and measures of psychopathology (subclinical psychotic experiences) were assessed across two waves (T 1 -2008 and T 2 -2014; n =2192) using the Composite International Diagnostic Interview. Results Measures of wider social environment at T 1 (high social control and social deprivation within neighbourhoods) was associated with emergence (OR=1.6; 95% CI=0.6-2.4) and persistence (OR=1.8; 95% CI=0.6-2.4) of psychotic experiences at T 2 . Also, measures of familial dysfunction and relationships were associated with emergence (OR=2.1; 95% CI=1.2-3.3) and persistence (OR=3.3; 95% CI=1.4-6.7) at T 2 . The associations between wider social environment and psychotic experiences were not significant after adjusting for measures of family dysfunction relationship. Conclusions The association between wider social environment and psychosis may be partially a result of dysfunctional relationships within the narrow environment including family. Current and past difficult family relationships may be an important contributing factor.

Subthreshold depression as a predictor of emergence and persistence of psychotic experiences: A six-year longitudinal population-based cohort

Introduction Subthreshold depression is prevalent in general population and is associated with poorer quality of life, higher health care use and increased risk of mental disorders mainly depression. Objectives Testing predictive impact of subthreshold depression on emergence and persistence of subclinical psychotic experiences. Aims To assess association between subthreshold depression and persistence of subclinical psychotic experiences in a 6-year follow-up of a representative general population sample. Methods A longitudinal prospective cohort study (the TurkSch The Izmir Mental Health Survey for Gene–Environment in Psychoses) was conducted with a general population sample ( n =4011) from Izmir, Turkey, who were 15–64 years of age at baseline. Sociodemographic factors, subthreshold depression (based on responses to systematic screening questions of the relevant questions with having less than five symptoms or having symptoms less than two weeks or having non-interfering impairment due to symptoms), and measures of psychopathology (subclinical psychotic experiences) were assessed across two waves (T 1 -2008 and T 2 -2014; n =2192) using the Composite International Diagnostic Interview. Results Prevalence estimates of subthreshold depression at T 1 and persisted psychotic experiences were 4.2% and 8.3%, respectively. Subthreshold depression at T 1 was associated with persistence (OR=1.6; 95% CI=0.6–2.9) of psychotic experiences at T 2 . Conclusions Psychosis may be a poor outcome of subthreshold extended phenotypes in the general population with early expression of sets of symptoms blending from depressive, anxious and psychotic states. Assessing the early dynamics of symptoms that affect each other over time may facilitate the understanding of the dynamic circuit of early psychopathology.

Testing the hypothesis that psychotic illness begins when subthreshold hallucinations combine with delusional ideation

While hallucinations and delusions are often considered as a single class of 'positive symptoms', little is known about their dynamic cooccurrence in relation to clinical outcome in non-help-seeking people. The Netherlands Mental Health and Incidence Study (NEMESIS-1) is a longitudinal study of mental disorders (n = 7075) with three measurements over a 3-year period. Risk factors, persistence of psychotic experiences, and clinical outcome were analyzed for groups with: i) no psychotic experiences, ii) only delusions, iii) only hallucinations, and iv) both delusions and hallucinations. Hallucinations and delusions occurred together more often (T0, 3.5%; T1, 1.0%; T2, 0.9%) than that predicted by chance (T0, 1.0%; T1, 0.1%; T2, 0.04%). The group with both symptoms showed more 'first-rank'-like delusions compared with the group with only delusions. Having both hallucinations and delusions, compared to isolated symptoms, was associated more strongly with risk factors, comorbid affective symptoms, negative symptoms, and persistence of psychotic experiences. This was not an artifact of having more symptoms in general. Experiencing both delusions and hallucinations is an indicator of greater etiological load resulting in more clinical outcome. A specific 'hallucinatory-delusional state' may represent an early phase of exacerbation of aberrant attribution of salience, increasing risk for clinical outcome.

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

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. 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). 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. 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.

Affective Dysregulation and Reality Distortion: A 10-Year Prospective Study of Their Association and Clinical Relevance

Evidence from clinical patient populations indicates that affective dysregulation is strongly associated with reality distortion, suggesting that a process of misassignment of emotional salience may underlie this connection. To examine this in more detail without clinical confounds, affective regulation-reality distortion relationships, and their clinical relevance, were examined in a German prospective cohort community study. A cohort of 2524 adolescents and young adults aged 14-24 years at baseline was examined by experienced psychologists. Presence of psychotic experiences and (hypo)manic and depressive symptoms was assessed at 2 time points (3.5 and up to 10 years after baseline) using the Munich-Composite International Diagnostic Interview. Associations were tested between level of affective dysregulation on the one hand and incidence of psychotic experiences, persistence of these experiences, and psychotic Impairment on the other. Most psychotic experiences occurred in a context of affective dysregulation, and bidirectional dose-response was apparent with greater level of both affective dysregulation and psychotic experiences. Persistence of psychotic experiences was progressively more likely with greater level of (hypo)manic symptoms (odds ratio [OR] trend=1.51, P<.001) and depressive symptoms (OR trend=1.15, P=.012). Similarly, psychotic experiences of clinical relevance were progressively more likely to occur with greater level of affective dysregulation (depressive symptoms: OR trend=1.28, P=.002; (hypo)manic symptoms: OR trend=1.37, P=.036). Correlated genetic liabilities underlying affective and nonaffective psychotic syndromes may be expressed as correlated dimensions in the general population. Also, affective dysregulation may contribute causally to the persistence and clinical relevance of reality distortion, possibly by facilitating a mechanism of aberrant salience attribution.

Does normal developmental expression of psychosis combine with environmental risk to cause persistence of psychosis? A psychosis proneness–persistence model

Research suggests that low-grade psychotic experiences in the general population are a common but transitory developmental phenomenon. Using two independent general population samples, the hypothesis was examined that common, non-clinical developmental expression of psychosis may become abnormally persistent when synergistically combined with developmental exposures that may impact on behavioural and neurotransmitter sensitization such as cannabis, trauma and urbanicity. The amount of synergism was estimated from the additive statistical interaction between baseline cannabis use, childhood trauma and urbanicity on the one hand, and baseline psychotic experiences on the other, in predicting 3-year follow-up psychotic experiences, using data from two large, longitudinal, random population samples from the Netherlands [The Netherlands Mental Health Survey and Incidence Study (NEMESIS)] and Germany [The Early Developmental Stages of Psychopathology (EDSP) study]. The 3-year persistence rates of psychotic experiences were low at 26% in NEMESIS and 31% in EDSP. However, persistence rates were progressively higher with greater baseline number of environmental exposures in predicting follow-up psychotic experiences (chi2=6.9, df=1, p=0.009 in NEMESIS and chi2=4.2, df=1, p=0.04 in EDSP). Between 21% and 83% (NEMESIS) and 29% and 51% (EDSP) of the subjects exposed to both environmental exposures and psychotic experiences at baseline had persistence of psychotic experiences at follow-up because of the synergistic action of the two factors. The findings suggest that environmental risks for psychosis act additively, and that the level of environmental risk combines synergistically with non-clinical developmental expression of psychosis to cause abnormal persistence and, eventually, need for care.

Do life events have their effect on psychosis by influencing the emotional reactivity to daily life stress?

Life events (LE) have consistently been found to influence course and outcome of psychotic disorders. However, the mechanism through which they operate is not known. The present study investigated whether LE have their effect by impacting on the emotional sensitivity for daily hassles. Patients with clinically remitted psychotic illness (N=42) were studied with the Experience Sampling Method (a structured diary technique assessing current context and mood in daily life) to assess: (1) appraised subjective stress related to daily events and activities; and (2) emotional reactivity conceptualized as changes in both negative affect (NA) and positive affect (PA). LE were assessed with the Brown & Harris Life Event and Difficulties Schedule. Multilevel regression analyses showed that previous exposure to LE influenced the appraised stressfulness of neither daily events nor the activities in which the subjects were involved. However, a history of LE did modify the emotional reaction to daily life stress, both in models predicting NA and in models predicting PA. By their cumulative effect on emotional reactivity to daily activities and events, LE may render individuals more vulnerable to the onset or persistence of psychotic experiences.