Exploring the interplay between psychotic experiences, functional somatic symptoms and health anxiety in childhood and adolescence - A longitudinal cohort study

BACKGROUND

Similarities exist between contemporary explanatory models underlying psychosis development, functional somatic symptoms, and health anxiety. The current study aimed to examine the potential interplay between psychotic experiences (and alternate measures of anomalous self-experiences and aberrant attribution of salience) and functional somatic symptoms on the outcome of health anxiety in youths.

METHODS

In a prospective general-population birth cohort, the Copenhagen Child Cohort 2000 (CCC2000), data from two time-points were available for 1122 individuals. We assessed the associations between psychotic experiences and functional somatic symptoms with health anxiety both cross-sectionally at ages 11- and 16-years, and longitudinally from age 11 to 16. Further, we examined if there was an interaction between these two domains on the outcome of health anxiety using the interaction contrast ratio.

RESULTS

Functional somatic symptoms and psychotic experiences were strongly cross-sectionally associated with health anxiety at both ages 11 and 16, even after adjustment for general psychopathology. In the longitudinal analyses, functional somatic symptoms, and psychotic experiences at age 11 were not individually associated with health anxiety at age 16 but having both functional somatic symptoms and psychotic experiences was: odds ratio 3.90, 95%CI 1.7-8.9, with suggestion of evidence for interaction beyond the additive effects. This association was attenuated after adjustment for general psychopathology: odds ratio 2.6, 95 % CI 1.0-6.4.

CONCLUSION

The strong associations between the domains support the idea of possible overlapping mechanisms underlying psychotic experiences, functional somatic symptoms, and health anxiety.

Cannabis use influences disorganized symptoms severity but not transition in a cohort of non-help-seeking individuals at-risk for psychosis from São Paulo, Brazil

BACKGROUND

Cannabis use is associated with an increased risk of developing a psychotic disorder. However, in individuals with at-risk mental states for psychosis (ARMS) this association is not clear, as well as the impact of cannabis use on symptom severity. The objective of this study was to evaluate the association of cannabis use patterns and ARMS risk status, transition to psychotic and psychiatric disorders, and psychopathology.

METHOD

A sample of 109 ARMS and 197 control individuals was drawn from the general population. Lifetime, maximum and current amount of cannabis use were assessed with the South Westminster modified questionnaire. Participants were followed-up for a mean of 2.5 years and reassessed for transition to any psychiatric disorder.

RESULTS

There were no differences between ARMS and controls regarding lifetime use, current amount of use, or maximum amount of cannabis use. There were also no differences between those who transitioned to a psychiatric disorder and those who did not regarding cannabis use variables. In ARMS individuals, cannabis use was significantly related to disorganization symptoms.

CONCLUSION

The results of this study suggest that cannabis plays a role in the psychopathology of ARMS individuals, leading to more severe symptomatology.

Cross-sectional association between metabolic parameters and psychotic-like experiences in a population-based sample of middle-aged and elderly individuals

BACKGROUND

Metabolic alterations are often found in patients with clinical psychosis early in the course of the disorder. Psychotic-like experiences are observed in the general population, but it is unclear whether these are associated with markers of metabolism.

METHODS

A population-based cohort of 1890 individuals (mean age 58.0 years; 56.3% women) was included. Metabolic parameters were measured by body-mass index (BMI), concentrations of low-density and high-density lipoprotein cholesterol (LDL-C and HDL-C), total cholesterol, triglycerides, and fasting glucose and insulin in blood. Frequency and distress ratings of psychotic-like experiences from the positive symptom dimension of the Community Assessment of Psychic Experience questionnaire were assessed. Cross-sectional associations were analysed using linear regression analyses.

RESULTS

Higher BMI was associated with higher frequency of psychotic-like experiences (adjusted mean difference: 0.04, 95% CI 0.02-0.06) and more distress (adjusted mean difference: 0.02, 95% CI 0.01-0.03). Lower LDL-C was associated with more psychotic-like experiences (adjusted mean difference: -0.23, 95% CI -0.40 to -0.06). When restricting the sample to those not using lipid-lowering medication, the results of BMI and LDL-C remained and an association between lower HDL-C and higher frequency of psychotic-like experiences was found (adjusted mean difference: -0.37, 95% CI -0.69 to -0.05). We observed no significant associations between cholesterol, triglycerides, glucose, insulin or homeostatic model assessment and psychotic-like experiences.

CONCLUSIONS

In a population-based sample of middle-aged and elderly individuals, higher BMI and lower LDL-C were associated with psychotic-like experiences. This suggests that metabolic markers are associated with psychotic-like experiences across the vulnerability spectrum.

The association between perceived racial discrimination and subclinical symptoms of psychosis

BACKGROUND

Schizophrenia is one of the most disabling disorders with the poorest outcomes. Cross-cultural research indicates an association between perceived racial discrimination and depression, anxiety, general psychological distress, and psychotic-spectrum disorders. Studies also find that coping moderates the relationship between discrimination and depression. Assessing subclinical symptoms may be useful in prevention efforts.

AIMS

The study aims to (1) assess if perceived racial discrimination is associated with psychosis subclinical symptoms among a non-clinical sample and (2) examine the role of maladaptive coping and depression, anxiety, and stress.

METHODS

The sample consisted of 261 ethnic minority undergraduate students. A structural equation model using a subclinical psychosis latent variable within a moderated mediation model assessed relationships between racial discrimination, maladaptive coping, depression, anxiety, and stress, and subclinical psychosis.

RESULTS

Perceived racial discrimination was associated with greater subclinical symptoms of psychosis through increased depression, anxiety, and stress at greater levels of maladaptive coping.

CONCLUSIONS

Knowing risk factors that can be targeted, such as perceived discrimination and maladaptive coping, may have implications for vulnerable populations.

Hearing spirits? Religiosity in individuals at risk for psychosis-Results from the Brazilian SSAPP cohort

In the last decades, biological and environmental factors related to psychosis were investigated in individuals at ultra-risk for psychosis (UHR) to predict conversion. Although religion relates to psychosis in a variety of ways, it is understudied in subclinical samples. Therefore, we assessed the interplay between religion and prodromal symptoms in 79 UHR and 110 control individuals. They were interviewed with the Duke University Religion Index and the Structured Interview for Prodromal Syndromes (SIPS). Organizational religious activity, a measure of how often someone attends churches/temples, was positively related to perceptual abnormalities/hallucinations (Spearman's rho = 0.262, p = 0.02). This relationship was replicated in a path analysis model (β = 0.342, SE = 0.108, p = 0.002), as well as a link between organizational religious activity and lower ideational richness (β = 0.401, SE = 0.105, p = 0.000) with no influence of sex, age, religious denomination, or socioeconomic class. Intrinsic religious activity was negatively correlated with suspiciousness (SIPS P2) (β = -0.028, SE = 0.009, p = 0.002), and non-organizational religious activity was correlated with higher ideational richness (N5) (β = -0.220, SE = 0.097, p = 0.023). We hypothesize that subjects with subclinical psychosis may possibly use churches and other religious organizations to cope with hallucinations. Indeed, Brazil is characterized by a religious syncretism and a strong influence of Spiritism in the popular culture. The mediumistic idea that some might be able to hear and/or see spirits is probably employed to explain subclinical hallucinations in the lay knowledge. Our results emphasize the importance of assessing religion and other region-specific aspects of various cultures when studying UHR individuals. This sort of assessment would enhance understanding of differences in conversion rates, and would help to transpose prevention programs from high-income countries to other settings.

Disruptions in White Matter Maturation and Mediation of Cognitive Development in Youths on the Psychosis Spectrum

BACKGROUND

Psychosis onset typically occurs in adolescence, and subclinical psychotic experiences peak in adolescence. Adolescence is also a time of critical neural and cognitive maturation. Using cross-sectional data from the Philadelphia Neurodevelopmental Cohort, we examined whether regional white matter (WM) development is disrupted in youths with psychosis spectrum (PS) features and whether WM maturation mediates the relationship between age and cognition in typically developing (TD) youths and youths with PS features.

METHODS

We examined WM microstructure, as assessed via diffusion tensor imaging, in 670 individuals (age 10-22 years; 499 TD group, 171 PS group) by using tract-based spatial statistics. Multiple regressions were used to evaluate age × group interactions on regional WM indices. Mediation analyses were conducted on four cognitive domains-executive control, complex cognition, episodic memory, and social cognition-using a bootstrapping approach.

RESULTS

There were age × group interactions on fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and retrolenticular internal capsule. Follow-up analyses revealed these effects were significant in both hemispheres. Bilateral SLF FA mediated the relationship between age and complex cognition in the TD group, but not the PS group. Regional FA did not mediate the age-associated increase in any of the other cognitive domains.

CONCLUSIONS

Our results showed aberrant age-related effects in SLF and retrolenticular internal capsule FA in youths with PS features. SLF development supports emergence of specific higher-order cognitive functions in TD youths, but not in youths with PS features. Future mechanistic explanations for these relationships could facilitate development of earlier and refined targets for therapeutic interventions.

Relationship between executive function, attachment style, and psychotic like experiences in typically developing youth

Psychotic like experiences (PLE's) are common in the general population, particularly during adolescence, which has generated interest in how PLE's emerge, and the extent to which they reflect either risk for, or resilience to, psychosis. The "attachment-developmental-cognitive" (ADC) model is one effort to model the effect of risk factors on PLEs. The ADC model proposes attachment insecurity as an early environmental insult that can contribute to altered neurodevelopment, increasing the likelihood of PLE's and psychosis. In particular, early-life attachment disruptions may negatively impact numerous aspects of executive function (EF), including behavioral inhibition and emotion regulation. Yet despite the relationship of disrupted attachment to EF impairments, no studies have examined how these factors may combine to contribute to PLE's in adolescents. Here, we examined the relative contributions of daily-life EF and attachment difficulties (avoidance and anxiety) to PLEs in typically developing youth (N=52; ages 10-21). We found that EF deficits and high attachment insecurity both accounted for a significant proportion of the variance in PLE's, and interacted to predict PLE manifestation. Specifically, positive PLEs were predicted by greater trouble monitoring behavioral impact, less difficulty completing tasks, greater difficulty regulating emotional reactions, greater difficulty controlling impulses and higher attachment anxiety. Negative PLEs were predicted by greater difficulty in alternating attention, transitioning across situations, and regulating emotional reactions as well as higher attachment anxiety. These results are consistent with the ADC model, providing evidence that early-life attachment disruptions may impact behavioral regulation and emotional control, which together may contribute to PLEs.

Subclinical psychosis and pain in an English national sample: The role of common mental disorders

BACKGROUND

Information on the association between subclinical psychosis and pain is scarce, and the role of common mental disorders (CMDs) in this association is largely unknown. The aim of the current study was to therefore assess this association in the general population using nationally representative data from England.

METHODS

Data for 7403 adults aged≥16years were used from the 2007 Adult Psychiatric Morbidity Survey. Five forms of psychotic symptoms were assessed by the Psychosis Screening Questionnaire, while pain was assessed in terms of the level of its interference with work activity in the past four weeks. The Clinical Interview Schedule Revised (CIS-R) was used to assess anxiety disorders, depressive episode, and mixed anxiety-depressive disorder (MADD). Participants with probable or definite psychosis were excluded. The association between psychotic symptoms and pain was assessed by ordinal and binary logistic regression analysis.

RESULTS

When adjusted for confounders other than CMDs, psychotic symptoms were significantly associated with pain [e.g., the OR (95%CI) for the severest form of pain (binary outcome) was 1.78 (1.11-2.85)]. However, this association was no longer significant when CMDs were controlled for in most analyses. Anxiety disorders and depressive episode explained 34.8%-47.1% of the association between psychotic symptoms and pain, while this percentage increased to 62.7%-78.0% when the sub-threshold condition of MADD was also taken into account.

CONCLUSIONS

When coexisting psychotic symptoms and pain are detected, assessing for anxiety and depression (even at sub-threshold levels) may be important for determining treatment options.

Psychotic-like experiences and disordered eating in the English general population

There are no studies on psychotic-like experiences (PLEs) and disordered eating in the general population. We aimed to assess this association in the English adult population. Data from the 2007 Adult Psychiatric Morbidity Survey (APMS) were analyzed. This was a nationally representative survey comprising 7403 English adults aged ≥16 years. The Psychosis Screening Questionnaire was used to identify the past 12-month occurrence of five forms of psychotic symptoms. Questions from the five-item SCOFF screening instrument were used to identify those with eating disorder (ED) symptoms and possible ED in the past year. The prevalence of any PLE was 5.1% (female) and 5.4% (male), while that of possible ED was 9.0% (female) and 3.5% (male). After adjustment for potential confounders, possible ED was associated with hypomania/mania in females (OR=3.23 95%CI=1.002-10.39), strange experiences [females (OR=1.85 95%CI=1.07-3.20) and males (OR=3.54 95%CI=1.65-7.57)], and any PLE in males (OR=3.44 95%CI=1.85-6.39). An interaction analysis revealed that the association was stronger among males for: auditory hallucinations and uncontrolled eating; and any PLE with uncontrolled eating, food dominance, and possible ED. Clinical practitioners should be aware that PLEs and disordered eating behavior often coexist. When one condition is detected, screening for the other may be advisable, especially among males.

The relationship between temperament and character and psychotic-like experiences in healthy children and adolescents

BACKGROUND

Prior work by our group identified personality profiles associated with psychotic-like experiences (PLE's) in healthy adults that were strikingly similar to those found in schizophrenia patients, with the exception of two key differences. Specifically, higher levels of PLE's were linked to higher persistence and cooperativeness, suggesting that these characteristics might represent personality-based resilience factors. Notably, age and personality were significantly correlated in these data, raising questions about whether healthy children and adolescents would show similar results. To date, no study has examined personality profiles associated with both positive and negative PLE's in healthy children and adolescents using Cloninger's Temperament and Character Inventory (TCI). Thus, this study examined the relationship between TCI dimensions and PLE's in healthy children and adolescents.

METHOD

The TCI and the Community Assessment of Psychic Experiences (CAPE) were administered to 123 healthy children and adolescents aged 8-18. Multiple regression models were used to examine personality dimensions associated with overall severity of PLE's as well as severity of positive and negative PLE's separately.

RESULTS

Positive, negative, and overall PLE severity were all associated with a personality pattern of higher harm avoidance and lower self-directedness. Negative PLE severity was also associated with lower persistence.

CONCLUSIONS

Personality correlates of PLE's in healthy children and adolescents were largely consistent with our past work on PLE's in healthy adults. However, our previously identified resilience factors were notably absent in this sample. These findings may suggest that these personality characteristics have not yet crystallized or emerged to aid in coping with PLE's.

Association between processing speed and subclinical psychotic symptoms in the general population: focusing on sex differences

Evidence is growing that persons along the schizophrenia spectrum, i.e., those who also display subclinical psychotic symptoms, exhibit deficits across a broad range of neuropsychological domains. Because sex differences in the association between cognitive deficits and psychosis have thus far been mostly neglected, we believe that ours is the first study specifically focused upon those differences when examining the relationship between subclinical psychosis and processing speed. Using a sample of 213 persons from the general population from Zurich, Switzerland, psychotic symptoms were assessed with three different questionnaires including the Schizotypal Personality Questionnaire, an adaptation of the Structured Interview for Assessing Perceptual Anomalies, and the Paranoia Checklist. Processing speed was assessed with the WAIS digit-symbol coding test. Two higher-order psychosis domains were factor-analytically derived from the various psychosis subscales and then subjected to a series of linear regression analyses. The results demonstrate that in both men and women associations between subclinical psychosis domains and processing speed were weak to moderate (β ranging from -0.18 to -0.27; all p<0.05). However, we found no sex-differences in the interrelation of subclinical psychosis and processing speed (ΔR(2)<0.005; p>0.30). In conclusion, it appears that sex differences in psychosis manifest themselves only at the high end of the continuum (full-blown schizophrenia) and not across the sub-threshold range. The small magnitude of the effects reported herein conforms to the etiopathology of the disorder. Since schizophrenia and related disorders from the spectrum are assumed to be multifactorial diseases, it follows that many etiological components of small effect are involved.

Season of birth and subclinical psychosis: systematic review and meta-analysis of new and existing data

Season of birth (SOB) has been shown to modify the risk of several health outcomes, including a number of neuropsychiatric disorders. Empirical evidence indicates that subclinical forms of psychosis in the general population share some risk factors with categorical diagnoses of psychosis. Hence, by systematically reviewing and meta-analyzing new and existing data, the current work aimed to determine whether there is evidence of an association between winter SOB and subclinical psychosis in the general population. Our meta-analytic results do not indicate an association between winter SOB and schizotypy in adult populations, although they indicate winter SOB may be a risk factor for psychotic experiences or symptoms in children around 12-15 years (OR=1.12, 95%CI:1.03-1.21). In the whole new dataset for adults (n=481, mean age=22.8 years) no association was detected in either an unadjusted model or adjusting for gender and age. Overall, our results indicate that the association between winter SOB and increased subclinical psychosis may hold in children, but does not in the broad general adult population. Nevertheless, the epidemiological and clinicopathological significance of winter SOB as a risk factor for subclinical psychosis would probably be slight due to the small effect sizes indicated by the reports available to date.

Stress sensitivity mediates the relationship between traumatic life events and attenuated positive psychotic symptoms differentially by gender in a college population sample

The purpose of this study was to investigate whether stress sensitivity mediates the relationship between traumatic life events and total attenuated positive psychotic symptoms, as well as the relationship between traumatic life events and endorsement of 8 or more attenuated positive psychotic symptoms as distressing (a threshold that has been associated with higher risk for psychosis in clinical groups). Participants (n = 671, aged 17-35, 29% male) were college students who were administered the Prodromal Questionnaire, the Perceived Stress Scale and the Life Events Checklist. Bootstrapping results indicated that stress sensitivity significantly mediated the relationships between traumatic life events and the number of attenuated positive psychotic symptoms endorsed and between traumatic life events and those who endorsed 8 or more distressing attenuated positive psychotic symptoms. Stratified gender analyses indicated the findings were specific to females. Results suggest that stress sensitivity may represent a specific vulnerability factor for risk of attenuated psychotic symptoms in those previously exposed to traumatic life events and that this liability appears stronger in females.

The relation between childhood maltreatment and psychosis in patients with schizophrenia and non-psychiatric controls

Several lines of evidence suggest that childhood maltreatment is associated with an increased risk for both psychotic disorders and subclinical psychotic-like experiences in the general population. Few studies, however, have sought to examine whether the strength of this relationship is comparable across patient and non-patient groups. The present study sought to compare the strength of the association between childhood maltreatment and self-reported psychotic symptoms in 447 healthy adult volunteers and 184 stable outpatients with schizophrenia or schizoaffective disorder. Strong positive correlations between childhood maltreatment and self-reported symptoms were observed in both groups. Although patients scored significantly higher than controls on both history of childhood maltreatment and self-reported symptoms, the strength of the relationship did not differ between groups. These data provide strong support for etiological continuity between subclinical psychotic symptoms and psychotic disorders.

Impact of childhood adversity on the onset and course of subclinical psychosis symptoms--results from a 30-year prospective community study

The study objective was to examine childhood adversity in association with intra-individual changes and inter-individual differences in subclinical psychosis in a representative community cohort over a 30-year period of observation. We analyzed two psychosis syndromes derived from the SCL-90-R - schizotypal signs and schizophrenia nuclear symptoms - in 335 participants. Participants were repeatedly assessed between 1978 (around age 20) and 2008 (around age 50). We focused specifically on inter-individual differences and intra-individual changes over time by applying structural equation modeling, generalized linear models, and generalized estimating equations. Several weak inter-individual differences revealed that increased schizotypal signs are related to various childhood adversities, such as being repeatedly involved in fights and parents having severe conflicts among themselves. We also found a significant positive association between schizotypal signs and the total number of adversities a subject experienced. This pointed toward a modest dose-response relationship. The intra-individual change in schizotypal signs over time was rather weak, although some adjustment did occur. In contrast, inter-individual schizophrenia nuclear symptoms were mainly unrelated to childhood adversity. However, some striking intra-individual changes in distress were noted over time, especially those linked with severe punishment and the total adversity score. In conclusion, we have confirmed previous positive findings about the association between childhood adversity and subsequent subclinical psychosis symptoms: An increase in adversity is weakly related to an increase of the psychosis symptom load. However, depending on the kind of adversity experienced the psychosis symptom load decreases gradually in adult life.

Latent profile analysis of healthy schizotypy within the extended psychosis phenotype

Converging evidence suggests that psychosis exists on a continuum, and that even mentally "healthy" individuals may experience subclinical psychotic experiences. However, little research has examined the subjective and psychological well-being of individuals in the putatively healthy end of the continuum. This study explored the latent profile structure of schizotypy in a non-clinical sample and compared subjective and psychological well-being across schizotypy profiles. Latent profile analysis was conducted on participants' responses (N=420) to the Oxford-Liverpool Inventory of Feelings and Experiences. Six latent profiles emerged: Low Schizotypy, Average, High Schizotypy, High Unusual Experiences (UE), High Introvertive Anhedonia, and High Introvertive Anhedonia/Cognitive Disorganization. Individuals in the profile characterized by high UE without negative, disorganized or impulsive features tended to endorse similar levels of well-being as the Average and Low Schizotypy profiles. With some exceptions, all three profiles also demonstrated significantly greater subjective and psychological well-being when compared to negative/disorganized schizotypy profiles. The UE profile most closely aligns with previous conceptualizations of "healthy schizotypy." Future research should investigate how individuals in this profile make sense of unusual or ambiguous experiences that may lead to distress in clinical populations.

Sex differences in resilience to childhood maltreatment: effects of trauma history on hippocampal volume, general cognition and subclinical psychosis in healthy adults

Recent data suggests that a history of childhood maltreatment is associated with reductions in hippocampal volume in healthy adults. Because this association is also evident in adults with psychiatric illness, it has been suggested that reductions in hippocampal volume associated with childhood maltreatment may be a risk factor for psychiatric illness. Such an interpretation suggests that healthy adults with a history of childhood maltreatment are more resilient to the effects of maltreatment. Current models of resilience suggest, however, that resiliency should be measured across multiple domains of functioning. The present study sought to investigate childhood maltreatment in relationship to hippocampal volumes in healthy adults and to address the question of whether the putative resiliency extends to other domains of functioning. Sixty-seven healthy Caucasian adults were assessed for a history of childhood emotional abuse, emotional neglect and physical abuse and received high resolution structural MR imaging scans. Participants with and without histories of abuse or neglect were compared on measures of total hippocampal volume, general cognitive ability and subclinical psychopathology. Our results suggest that childhood emotional abuse is associated with reduced hippocampus volume in males, but not in females. However, emotional abuse was associated with higher levels of subclinical psychopathology in both males and females. These data suggest that while females may be more resilient to the neurological effects of childhood maltreatment, they are not more resilient to the psychiatric symptoms associated with childhood maltreatment. Further research is needed to elucidate the mechanisms involved in these different levels of resilience.