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Psychotic experiences (PE) are common in the general population, in particular in childhood, adolescence and young adulthood. PE have been shown to be associated with an increased risk for later psychotic disorders, mental disorders, and poorer functioning. Recent findings have highlighted the relevance of PE to many fields of healthcare, including treatment response in clinical services for anxiety & depression treatment, healthcare costs and service use. Despite PE relevance to many areas of mental health, and healthcare research, there remains a gap of information between PE researchers and experts in other fields. With this review, we aim to bridge this gap by providing a broad overview of the current state of PE research, and future directions. This narrative review aims to provide an broad overview of the literature on psychotic experiences, under the following headings: (1) Definition and Measurement of PE; (2) Risk Factors for PE; (3) PE and Health; (4) PE and Psychosocial Functioning; (5) Interventions for PE, (6) Future Directions.
To estimate the prevalence of DSM-V mental disorders in a population of Irish emerging adults
Mental disorders are the leading cause of years lived with disability in youth worldwide. Few studies use gold standard of face to face semi-structured standardized interview tools, and this is a limitation in the estimates of prevalence rates of mental disorder in the extant literature.
Briefly, we recruited a representative sample of 212 adolescents and followed them up over ten years. In this wave of the adolescent brain development study, 103 of the initial 212 participants took part, 50 males and 53 females, with a mean age of 20.87 years (SD = 1.3). Psychopathology was assessed in all participants by trained research psychologists and mental health professionals using the Structured Clinical Interview for DSM-V (SCID).
52.4% of participants had one lifetime mental disorder, the prevalence rates were highest for Major Depressive Episode (25.3%), Social Anxiety (12.6%) and Generalized Anxiety (8.7%). 50.5% had a history of a mental disorder. 27.2% had 1 lifetime diagnosis, 15.5% had 2 and 7.8% had >2.
Rates of mental disorder rapidly increase during emerging adulthood. In a similar Irish study, 55% of young adults met the criteria for lifetime mental disorder. Whilst the rates of mental disorder are high in young people, previous longitudinal research has suggested that many common mental disorders remit by the late twenties. We suggest a need for further research investigating the comparative later functional and economic outcomes of these young people. Research to date is supportive of a need to expand capacity of youth friendly services for prevention and treatment.
Ethical approval for the study protocols, including interviews and assessments, along with informed consent documents, was granted by the Beaumont Hospital Medical Ethics Committee in 2016.
1. European Research Council Consolidator Award and Health Research Board Ireland Award to Mary Cannon
2. Health Professionals Fellowship from the Health Research Board Ireland to Helen Coughlan.
Psychotic experiences (PE) are highly prevalent in childhood and are known to be associated with co-morbid mental health disorders and functional difficulties in adolescence. However, little is known about the long-term outcomes of young people who report PE.
As part of the Adolescent Brain Development Study, 211 young people were recruited in childhood (mean age 11.7 years) and underwent detailed clinical interviews, with 25% reporting PE. A 10 year follow-up study was completed and 103 participants returned (mean age 20.9 years). Structured clinical interviews for DSM-5 (SCID-5) and interviewer-rated assessments of functioning were conducted. A detailed neuropsychological battery was also administered. Analyses investigated group differences between those who had ever reported PE and controls in early adulthood.
The PE group was at a significantly higher risk of meeting DSM-5 criteria for a current (OR 4.08, CI 1.16–14.29, p = 0.03) and lifetime psychiatric disorder (OR 3.27, CI 1.43–7.47, p = 0.005). They were also at a significantly higher risk of multi-morbid lifetime psychiatric disorders. Significantly lower scores on current social and global functioning measures were observed for the PE group. Overall, there were no differences in neuropsychological performance between groups apart from significantly lower scores on the Stroop Word task and the Purdue Pegboard task for the PE group.
Our findings suggest that reports of PE are associated with poorer mental health and functional outcomes in early adulthood, with some persisting cognitive and motor deficits. Young people who report such symptoms could be considered a target group for interventions to aid functional outcomes.
Psychotic experiences (PEs) are reported by a significant minority of adolescents and are associated with the development of psychiatric disorders. The aims of this study were to examine associations between PEs and a range of factors including psychopathology, adversity and lifestyle, and to investigate mediating effects of coping style and parental support on associations between adversity and PEs in a general population adolescent sample.
Cross-sectional data were drawn from the Irish centre of the Saving and Empowering Young Lives in Europe study. Students completed a self-report questionnaire and 973 adolescents, of whom 522 (53.6%) were boys, participated. PEs were assessed using the 7-item Adolescent Psychotic Symptom Screener.
Of the total sample, 81 (8.7%) of the sample were found to be at risk of PEs. In multivariate analysis, associations were found between PEs and number of adverse events reported (OR 4.48, CI 1.41–14.25; p < 0.011), maladaptive/pathological internet use (OR 2.70, CI 1.30–5.58; p = 0.007), alcohol intoxication (OR 2.12, CI 1.10–4.12; p = 0.025) and anxiety symptoms (OR 4.03, CI 1.57–10.33; p = 0.004). There were small mediating effects of parental supervision, parental support and maladaptive coping on associations between adversity and PEs.
We have identified potential risk factors for PEs from multiple domains including adversity, mental health and lifestyle factors. The mediating effect of parental support on associations between adversity and PEs suggests that poor family relationships may account for some of this mechanism. These findings can inform the development of interventions for adolescents at risk.
Psychotic experiences (PEs) are common in childhood and adolescence and their association with mental disorders is well-established. We aim to conduct a quantitative synthesis the literature on the relationship between childhood and adolescent PEs and (i) any mental disorder; and (ii) specific categories of mental disorder, while stratifying by study design.
Three electronic databases (PUBMED, PsycINFO and EMBASE) were searched from inception to August 2017 for all the published literature on childhood and adolescent PEs and mental disorder (outcome) in non-help-seeking community samples. Study quality was assessed using a recognised quality assessment tool for observational studies. Two authors conducted independent data extraction. Pooled odds ratios were calculated for mental disorders using random-effects models. Additional analyses were conducted investigating different categories of mental disorder while stratifying by study design.
Fourteen studies from 13 community samples (n = 29 517) were identified with 9.8% of participants reporting PEs. PEs were associated with a three-fold increased risk of any mental disorder [odds ratio (OR) 3.08, confidence interval (CI) 2.26–4.21, k = 12]. PEs were associated with four-fold increase risk of psychotic disorder (OR 3.96, CI 2.03–7.73, population-attributable-fraction: 23.2%, k = 5). In addition, PEs were associated with an increased risk of affective disorders, anxiety disorders, behavioural disorders and substance-use disorders. Few longitudinal studies have investigated childhood and adolescent PEs and subsequent non-psychotic disorders which limited a meaningful synthesis and interpretation of these results.
This meta-analysis confirms that PEs are prevalent in childhood and adolescent community samples and are associated with a variety of mental disorders beyond psychotic disorders. Further longitudinal research is necessary to fully determine the longitudinal relationship between PEs and non-psychotic disorders.
There has been a resurgence of interest in the role of childhood trauma in the aetiology of psychosis. In this review, recent findings on the association between childhood trauma and a continuum of psychotic symptoms are presented. Evidence of the association between specific childhood trauma subtypes and psychotic symptoms is examined, with a brief discussion of some current hypotheses about the potential mechanisms underlying the associations that have been found. Some practice implications of these findings are also highlighted.
• Identify findings from recent meta-analyses on the association between childhood trauma and a range of psychotic outcomes, from non-clinical psychotic experiences to psychotic disorders
• Consider which childhood traumas are the most potent in the context of psychotic outcomes
• Recognise that the relationships between childhood trauma, psychotic symptoms and other psychopathology are complex, dynamic and multidimensional
In the frame of the COST ACTION ‘EMBOS’ (Development and implementation of a pan-European Marine Biodiversity Observatory System), coverage of intertidal macroalgae was estimated at a range of marine stations along the European coastline (Subarctic, Baltic, Atlantic, Mediterranean). Based on these data, we tested whether patterns in macroalgal diversity and distribution along European intertidal rocky shores could be explained by a set of meteo-oceanographic variables. The variables considered were salinity, sea surface temperature, photosynthetically active radiation, significant wave height and tidal range and were compiled from three different sources: remote sensing, reanalysis technique and in situ measurement. These variables were parameterized to represent average conditions (mean values), variability (standard deviation) and extreme events (minimum and maximum values). The results obtained in this study contribute to reinforce the EMBOS network approach and highlight the necessity of considering meteo-oceanographic variables in long-term assessments. The broad spatial distribution of pilot sites has allowed identification of latitudinal and longitudinal gradients manifested through species composition, diversity and dominance structure of intertidal macroalgae. These patterns follow a latitudinal gradient mainly explained by sea surface temperature, but also by photosynthetically active radiation, salinity and tidal range. Additionally, a longitudinal gradient was also detected and could be linked to wave height.
Examining how variability in population abundance and distribution is allotted among different spatial scales can inform of processes that are likely to generate that variability. Results of studies dealing with scale issues in marine benthic communities suggest that variability is concentrated at small spatial scales (from tens of centimetres to few metres) and that spatial patterns of variation are consistent across ecosystems characterized by contrasting physical and biotic conditions, but this has not been formally tested. Here we quantified the variability in the distribution of intertidal rocky shore communities at a range of spatial scales, from tens of centimetres to thousands of kilometres, both in the NE Atlantic and the Mediterranean, and tested whether the observed patterns differed between the two basins. We focused on canopy-forming macroalgae and associated understorey assemblages in the low intertidal, and on the distribution of Patella limpets at mid intertidal levels. Our results highlight that patterns of spatial variation, at each scale investigated, were consistent between the Atlantic and the Mediterranean, suggesting that similar ecological processes operate in these regions. In contrast with former studies, variability in canopy cover, species richness and limpet abundance was equally distributed among spatial scales, possibly reflecting the fingerprint of multiple processes. Variability in community structure of low intertidal assemblages, instead, peaked at the largest scale, suggesting that oceanographic processes and climatic gradients may be important. We conclude that formal comparisons of variability across scales nested in contrasting systems are needed, before any generalization on patterns and processes can be made.
Coastal ecosystems are highly complex and driven by multiple environmental factors. To date we lack scientific evidence for the relative contribution of natural and anthropogenic drivers for the majority of marine habitats in order to adequately assess the role of different stressors across the European seas. Such relationship can be investigated by analysing the correlation between environmental variables and biotic patterns in multivariate space and taking into account non-linearities. Within the framework of the EMBOS (European Marine Biodiversity Observatory System) programme, hard bottom intertidal communities were sampled in a standardized way across European seas. Links between key natural and anthropogenic drivers and hard bottom communities were analysed using Boosted Regression Trees modelling. The study identified strong interregional variability and showed that patterns of hard bottom macroalgal and invertebrate communities were primarily a function of tidal regime, nutrient loading and water temperature (anomalies). The strength and shape of functional form relationships varied widely however among types of organisms (understorey algae composing mostly filamentous species, canopy-forming algae or sessile invertebrates) and aggregated community variables (cover or richness). Tidal regime significantly modulated the effect of nutrient load on the cover and richness of understorey algae and sessile invertebrates. In contrast, hydroclimate was more important for canopy algae and temperature anomalies and hydroclimate separately or interactively contributed to the observed patterns. The analyses also suggested that climate-induced shifts in weather patterns may result in the loss of algal richness and thereby in the loss of functional diversity in European hard bottom intertidal areas.
Within the COST action EMBOS (European Marine Biodiversity Observatory System) the degree and variation of the diversity and densities of soft-bottom communities from the lower intertidal or the shallow subtidal was measured at 28 marine sites along the European coastline (Baltic, Atlantic, Mediterranean) using jointly agreed and harmonized protocols, tools and indicators. The hypothesis tested was that the diversity for all taxonomic groups would decrease with increasing latitude. The EMBOS system delivered accurate and comparable data on the diversity and densities of the soft sediment macrozoobenthic community over a large-scale gradient along the European coastline. In contrast to general biogeographic theory, species diversity showed no linear relationship with latitude, yet a bell-shaped relation was found. The diversity and densities of benthos were mostly positively correlated with environmental factors such as temperature, salinity, mud and organic matter content in sediment, or wave height, and related with location characteristics such as system type (lagoons, estuaries, open coast) or stratum (intertidal, subtidal). For some relationships, a maximum (e.g. temperature from 15–20°C; mud content of sediment around 40%) or bimodal curve (e.g. salinity) was found. In lagoons the densities were twice higher than in other locations, and at open coasts the diversity was much lower than in other locations. We conclude that latitudinal trends and regional differences in diversity and densities are strongly influenced by, i.e. merely the result of, particular sets and ranges of environmental factors and location characteristics specific to certain areas, such as the Baltic, with typical salinity clines (favouring insects) and the Mediterranean, with higher temperatures (favouring crustaceans). Therefore, eventual trends with latitude are primarily indirect and so can be overcome by local variation of environmental factors.
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