Non-clinical Psychotic Symptoms Research Articles

Persistence of psychosis in the population: Τhe cost and the price for humanity

Schizophrenia is a chronic and highly impairing condition that affects around 1% of the human population. Evolutionary theories lend support for the idea of a continuum approach to the diagnosis of psychosis. Subclinical psychotic-like experiences are relatively common in children and adolescents, occurring in about 17% of youths. The prevalence rate of psychotic symptoms in the general population is up to 8%, which is about ten times higher than the prevalence of diagnosed psychotic disorders. Some scientists have argued that there may be a shared genetic variation between illness and non-clinical psychotic- like symptom expression. The high prevalence of non-clinical psychotic symptoms in the population prompt neuroscientists to re-evaluate these symptoms in the light of evolutionary theory. The schizophrenia impaired physical health and reduced probability of reproduction raises an evolutionary puzzle. How does schizophrenia persist in the population at a stable prevalence rate? The question regarding what processes maintain the persistence of high heritable variation in relatively disadvantageous traits, such as schizotypy, in the general population, remains a universal challenge across the domains of psychiatric and evolutionary genetics. Furthermore, is there any link between the evolutionary persistence of psychosis in the population worldwide and the association of creativity with psychoticlike experiences in the general population? There has been a healthy debate on many hypotheses. One possibility is that schizophrenia remains in the human population because of shared genetic linkages to creativity. During last decade many scientists search the explanation for the evolutionary enigma of the persistence of schizophrenia, and the nature of its relation to creativity, although the notion that there is a heritable aspect of at least some aspects of high ability, including creativity, is going back at least to Francis Galton's book Hereditary genius (1869). Neuroscientists also suggested that schizophrenia may emerge as a by-product of social cognition or that certain types of hallucinations could be viewed as evolutionary by-products of a cognitive system designed to detect threat. Some traits, such as schizotypy, may have an optimal level of expression that is advantageous within the community. However, this trait has adverse consequences for the psychotic person, which becomes, as Sebastian Faulks (2006) suggested, "the price we pay for being what we are".

Arousal Predisposition as a Vulnerability Indicator for Psychosis: A General Population Online Stress Induction Study.

Explanatory models ascribe to arousability a central role for the development of psychotic symptoms. Thus, a disposition to hyperarousal (i.e., increased arousal predisposition (AP)) may serve as an underlying vulnerability indicator for psychosis by interacting with stressors to cause symptoms. In this case, AP, stress-response, and psychotic symptoms should be linked before the development of a diagnosable psychotic disorder. We conducted a cross-sectional online study in a population sample (N = 104; M age = 27.7 years, SD = 11.2, range 18–70). Participants rated their AP and subclinical psychotic symptoms. Participants reported their stress-levels before and after two stress inductions including an arithmetic and a social stressor. The participants with an increased AP generally felt more stressed. However, AP was not associated with the specific stress-response. As expected, positive psychotic symptoms were significantly associated with AP, but this was not mediated by general stress-levels. Its association to subtle, nonclinical psychotic symptoms supports our assumption that AP could be a vulnerability indicator for psychosis. The trait is easily accessible via a short self-report and could facilitate the identification of people at risk and be a promising target for early stress-management. Further research is needed to clarify its predictive value for stress-responses.

Effects of Multidimensional Treatment Foster Care on Psychotic Symptoms in Girls

Neurodevelopmental theories of psychosis highlight the potential benefits of early intervention, prevention, and/or preemption. How early intervention should take place has not been established, nor whether interventions based on social learning principles can have preemptive effects. The objective was to test whether a comprehensive psychosocial intervention can significantly alter psychotic symptom trajectories during adolescence-a period of heightened risk for a wide range of psychopathology. This study was a randomized controlled trial (RCT) of Multidimensional Treatment Foster Care (MTFC) for delinquent adolescent girls. Assessment of psychotic symptoms took place at baseline and then 6, 12, 18, and 24 months post-baseline using a standardized self-report instrument (Brief Symptom Inventory). A second source of information about psychotic symptoms was obtained at baseline or 12 months, and again at 24 months using a structured diagnostic interview (the Diagnostic Interview Schedule for Children [DISC]). Significant benefits for MTFC over treatment as usual for psychosis symptoms were observed over a 24-month period. Findings were replicated across both measures. Effects were independent of substance use and initial symptom severity and persisted beyond the initial intervention period. Ameliorating nonclinical psychotic symptoms trajectories beginning in mid-adolescence via a multifaceted psychosocial intervention is possible. Developmental research on nonclinical psychotic symptoms and their prognostic value should be complemented by more psychosocial intervention research aimed at modifying these symptom trajectories early in their natural history. Clinical trial registration information-Juvenile Justice Girls Randomized Control Trial: Young Adult Follow-up; http://clinicaltrials.gov; NCT01341626.

Cortical thickness in individuals with non-clinical and clinical psychotic symptoms.

Symptoms that are linked to psychosis are also experienced by individuals who are not in need of care. In the present study, cortical thickness was investigated in these individuals. Fifty individuals with non-clinical auditory verbal hallucinations (most of them also experienced other non-clinical psychotic symptoms), 50 patients with a psychotic disorder and auditory verbal hallucinations, and 50 healthy control subjects underwent structural magnetic resonance imaging. Data were analysed using FreeSurfer. Cortical thickness in the pars orbitalis, paracentral lobule, fusiform gyrus and inferior temporal gyrus was lowest in patients, intermediate in the non-clinical hallucinating group, and highest in control subjects. The patients also showed thinning in widespread additional areas compared to the two other groups, whereas both hallucinating groups showed similar levels of thinning in the insula. Ranking the levels of cortical thickness per brain region across groups revealed that for 88% of brain regions, cortical thickness was lowest in patients, intermediate in the non-clinical hallucinating group, and highest in controls. These findings show that individuals with non-clinical psychotic symptoms show a similar but less pronounced pattern of cortical thinning as patients with a psychotic disorder, which is suggestive of a similar, but milder underlying pathophysiology in this group compared to the psychosis group.

EPA-1053 – Cortical thickness in individuals with nonclinical and clinical psychotic symptoms

Introduction Symptoms that are linked to schizophrenia and other psychotic disorders, such as auditory verbal hallucinations (AVH), are also commonly reported by individuals who function well in society. These individuals are not in need for care, do not suffer from schizotypal personality disorder or other psychotic disorders, and provide the opportunity to investigate the relationship between nonclinical psychotic symptoms and brain morphology. Methods Fifty individuals with nonclinical AVH, 50 patients with a psychotic disorder and AVH, and 50 healthy controls underwent structural magnetic resonance imaging. The three groups were matched for age, gender, handedness and years of parental education. Cortical thickness was assessed using the FreeSurfer software suite. Results Cortical thickness in the left pars orbitalis, left paracentral gyrus, right fusiform gyrus and right inferior temporal gyrus was lowest in patients, intermediate in the nonclinical AVH group, and highest in controls. The patients also showed additional cortical thinning in widespread frontal, temporal and parietal areas compared to both other groups. In additional analysis, ranking the levels of cortical thickness per brain region across groups revealed that for the large majority of brain regions (88%), the patients had the lowest cortical thickness, the nonclinical individuals with AVH were in between, and the control subjects had the highest cortical thickness. Discussion Individuals with nonclinical psychotic symptoms show a similar but less pronounced pattern of cortical thinning as patients with a psychotic disorder, which is suggestive of a similar, but milder underlying pathophysiology in the nonclinical hallucinating group compared to the psychosis group.

1250 Delusional Ideation in Young Adulthood is Associated with Grey and White Matter Alterations in Adolescence

Background and AimsSeveral studies have described an association between very preterm birth and psychiatric problems later in life. We aimed to investigate whether young adults who were born very preterm...

Childhood bullying and the association with psychosis in non-clinical and clinical samples: a review and meta-analysis

Approximately 11% of schoolchildren are bullied on a regular basis. It has been argued that continuous exposure to stress is related to the development of psychotic symptoms. The current study sought to investigate whether being bullied in childhood is related to the development of psychotic symptoms. A search of PubMed, PsycINFO and EMBASE was conducted. The reference lists of included papers were searched to identify other eligible papers. A meta-analysis was performed on a subgroup of studies. We found four clinical and 10 general population studies that met inclusion criteria. The results of the clinical studies were mixed. However, the results of the non-clinical studies provided more consistent evidence that school bullying is related to the development of non-clinical psychotic symptoms. Stronger associations were found with increased frequency and severity and longer duration of being bullied. We performed a meta-analysis on seven population-based studies, yielding unadjusted and adjusted odds ratios (ORs) of 2.7 [95% confidence interval (CI) 2.1-3.6] and 2.3 (95% CI 1.5-3.4) respectively. Although there is some evidence of an association between bullying and psychosis in clinical samples, the research is too sparse to draw any firm conclusions. However, population-based non-clinical studies support the role of bullying in the development of psychotic symptoms later in life. These findings are consistent with findings of an increased risk of psychotic symptoms among those exposed to other types of abuse.

Childhood facial emotion recognition and psychosis-like symptoms in a nonclinical population at 12 years of age: Results from the ALSPAC birth cohort

Introduction. Nonclinical psychotic symptoms (for example, low intensity or low frequency psychotic symptoms such as ideas of reference or single word auditory hallucinations) are common in adolescents and may be associated with an increased risk of developing a psychotic disorder in adulthood. Those at high risk of developing a psychotic disorder appear to perform poorly on facial emotion recognition tasks but the relationship between facial emotion recognition and nonclinical “psychosis like symptoms” (PLIKS) in children is unclear. We aimed to examine the association between childhood facial emotion recognition and PLIKS in adolescents. Methods. Longitudinal study using a large birth cohort. 6455 subjects completed a semistructured clinical assessment for psychotic symptoms (the PLIKSi) at the mean age of 12.9 (SD=0.23). Facial emotion recognition (using the DANVA) was previously assessed at the age of 8 in the cohort. Results. There was no increase in odds of reporting any PLIKS either in relation to the total score on the measure of facial emotion recognition or for the individual emotion scores of fear, sadness, anger, and happiness. Similar results were also found when examining more intense and/or more frequently experienced psychotic symptoms. Conclusions. Deficits in facial emotion recognition in 8-year-olds do not appear to predict later reporting of nonclinical psychotic symptoms in early adolescence. The results do not support the proposal that recognition of emotion is a trait phenomenon in those individuals at increased risk for psychosis. However, further research is warranted in older children/adolescents when more subtle emotion recognition deficits can be investigated.

Schizophrenia risk factors constitute general risk factors for psychiatric symptoms in the population

BackgroundThe presence of a psychosis continuum is suggested by studies showing that schizophrenia and non-clinical psychotic symptoms in the general population share the same risk factors. However, to our knowledge no large-scale studies have been conducted which examine the specificity of these risk factors in the general population. AimTo investigate whether socio-demographic characteristics associated with non-clinical psychotic symptoms are also associated with other psychiatric symptoms. And secondly, to examine to what extent concomitant psychiatric symptoms explain the relationship between socio-demographic characteristics and non-clinical psychotic symptoms. MethodsIn a general population sample of 4894 subjects (mean age 39years, 45% men) from the Utrecht Health Project we investigated the associations of socio-demographical characteristics with non-clinical psychotic symptoms and other psychiatric symptoms by using the SCL-90. We examined these associations using multivariable logistic regression analyses with and without controlling for the presence of other psychiatric symptoms. ResultsParticipants with non-clinical psychotic symptoms had an 89% probability of concomitant depressive, anxiety or phobic anxiety symptoms, compared to 11% in participants without psychotic symptoms. The risk profiles for non-clinical psychotic symptoms and other psychiatric symptoms were largely similar. Non-Dutch ethnicity was most strongly associated with non-clinical psychotic symptoms. Adjusting for other psychiatric symptoms did not increase the specificity of the risk factors. ConclusionSocio-demographic risk factors for non-clinical psychotic symptoms in the general population are also risk factors for other psychiatric symptoms. The relationship between these risk factors and psychotic symptoms are for a substantial part explained by an increase in other psychiatric symptoms.

Perinatal folate-related exposures and risk of psychotic symptoms in the ALSPAC birth cohort

BackgroundIt is unclear to what extent non-clinical psychotic experiences during childhood and adolescence share underlying aetiological mechanisms with schizophrenia. One candidate mechanism for schizophrenia involves the epigenetic status of the developing fetus, which depends on the internal folate-status of mother and child. Our study examines the relationships between multiple determinants of perinatal folate-status and development of psychotic experiences in adolescence. MethodsStudy participants were up to 5344 mother–child pairs from the Avon Longitudinal Study of Parents and their Children, UK, with information on maternal and/or child MTHFR C677T genotype, maternal folate intake (supplementation at 18/32- weeks gestation; dietary intake at 32- weeks gestation) and psychosis-like symptoms (PLIKS) for children assessed at age 12. ResultsNominal evidence was observed that maternal folate supplementation at 18weeks increased the odds of PLIKS in children (odds ratio(OR)=1.34; 95%-CI:[1.00;1.76]) and, consistent with this, that children of MTHFR C667T TT homozygous mothers had decreased odds of PLIKS (OR=0.72; 95%CI:[0.50;1.02]; recessive model) with strongest effects in boys (OR=0.44, 95%-CI:[0.22;0.79]; sex-specific p=0.029). None of the reported effects remained significant when corrected for multiple testing. ConclusionsOverall, this study found no support that maternal/child MTHFR C677T genotype and maternal folate intake during pregnancy contribute to common aetiological pathways that are shared between schizophrenia and non-clinical psychotic symptoms in adolescents, assuming that decreased folate-status increases schizophrenia risk.

Association of measures of fetal and childhood growth with non-clinical psychotic symptoms in 12-year-olds: the ALSPAC cohort.

BackgroundPrevious studies have suggested that impaired fetal and childhood growth are associated with an increased risk of schizophrenia, but the association of pre-adult growth with non-clinical psychotic symptoms (psychosis-like symptoms) in children is not known.AimsTo explore the associations of body size at birth and age 7.5 years with childhood psychosis-like symptoms.MethodProspective cohort of children followed up from birth to age 12: the ALSPAC cohort.ResultsData on 6000 singleton infants born after 37 weeks of gestation. A one standard deviation increase in birth weight was associated with an 18% reduction in the risk of definite psychosis-like symptoms after adjusting for age and gestation (Odds ratio (OR) = 0.82, 95% CI = 0.73–0.92, P = 0.001). This association was partly confounded by maternal anthropometry, smoking during pregnancy, socioeconomic status and IQ. A similar association was seen for birth length and psychosis-like symptoms, which disappeared after controlling for birth weight. There was little evidence for an association of 7-year height or adiposity with psychosis-like symptoms.ConclusionsMeasures of impaired fetal, but not childhood, growth are associated with an increased risk of psychosis-like symptoms in 12-year-olds.

Investigating whether adverse prenatal and perinatal events are associated with non-clinical psychotic symptoms at age 12 years in the ALSPAC birth cohort

Non-clinical psychosis-like symptoms (PLIKS) occur in about 15% of the population. It is not clear whether adverse events during early development alter the risk of developing PLIKS. We aimed to examine whether maternal infection, diabetes or pre-eclampsia during pregnancy, gestational age, perinatal cardiopulmonary resuscitation or 5-min Apgar score were associated with development of psychotic symptoms during early adolescence. A longitudinal study of 6356 12-year-old adolescents who completed a semi-structured interview for psychotic symptoms in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. Prenatal and perinatal data were obtained from obstetric records and maternal questionnaires completed during pregnancy. The presence of definite psychotic symptoms was associated with maternal infection during pregnancy [adjusted odds ratio (OR) 1.44, 95% confidence interval (CI) 1.11-1.86, p=0.006], maternal diabetes (adjusted OR 3.43, 95% CI 1.14-10.36, p=0.029), need for resuscitation (adjusted OR 1.50, 95% CI 0.97-2.31, p=0.065) and 5-min Apgar score (adjusted OR per unit decrease 1.30, 95% CI 1.12-1.50, p<0.001). None of these associations were mediated by childhood IQ score. Most associations persisted, but were less strong, when including suspected symptoms as part of the outcome. There was no association between PLIKS and gestational age or pre-eclampsia. Adverse events during early development may lead to an increased risk of developing PLIKS. Although the status of PLIKS in relation to clinical disorders such as schizophrenia is not clear, the similarity between these results and findings reported for schizophrenia indicates that future studies of PLIKS may help us to understand how psychotic experiences and clinical disorders develop throughout the life-course.

IQ and non-clinical psychotic symptoms in 12-year-olds: results from the ALSPAC birth cohort

BackgroundNon-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear.AimsTo investigate the prevalence, nature and frequency of psychosis-like symptoms in 12-year-old children and study their relationship with IQ.MethodLongitudinal study using the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. A total of 6455 children completed screening questions for 12 psychotic symptoms followed by a semi-structured clinical assessment. IQ was assessed at 8 years of age using the Wechsler Intelligence Scale for Children (3rd UK edition).ResultsThe 6-month period prevalence for one or more symptoms was 13.7% (95% CI 12.8–14.5). After adjustment for confounding variables, there was a non-linear association between IQ score and psychosis-like symptoms, such that only those with below average IQ score had an increased risk of reporting such symptoms.ConclusionsNon-clinical psychotic symptoms occur in a significant proportion of 12-year-olds. Symptoms are associated with low IQ and also less strongly with a high IQ score. The pattern of association with IQ differs from that observed in schizophrenia.