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S30. UNDERSTANDING THE NATURE OF CHILDHOOD SUSPICIOUSNESS: A QUALITATIVE STUDY

Abstract Background Paranoia exists on a continuum of severity in adult patient populations and more recently it has been found to exist in children and adolescents in the general population. Childhood paranoia, assessed by the Social Mistrust Scale (SMS), has been found to be related to both internalising and externalising problem behaviours (Wong, Freeman & Hughes, 2014); however, the nature of why children’s suspicions are related to psychosocial functioning remains unexamined. The current qualitative study addresses this gap by following up the original 2014 sample to examining the nature of children’s suspicions using thematic analysis. By giving voice to children and adolescents, I will discuss: 1) children’s definition of trust and mistrust more broadly 2) the common themes generated from interview questions about children’s suspicions in relation to baseline self-reported levels of suspiciousness on the Social Mistrust Scale (SMS) and 3) other developmental psychosocial factors contributing to childhood suspicions. This study is also the first study to address whether or not children’s suspicions are valid, or grounded in reality, using interviewer ratings and child self-report measures of mistrust. Methods 118 trusting and persistently mistrustful children from the UK (n=40) and Hong Kong (n=78) were matched and followed-up at 6 and 12 months based on their self-reported levels of suspiciousness on the Social Mistrust Scale. Correlations and kappas were conducted to assess the stability and convergent validity between assessments. Thematic analysis was conducted on 95 (80%) randomly selected semi-structured interviews about mistrust. The coding scheme generated from this analysis was further tested on the remaining transcripts for discriminant validity. Results Children’s definition of trust was consistent with existing developmental literature. Commonly discussed topics related to mistrust, particularly school mistrust, included (i) experiences of bullying, concerns with popularity and the consequences of being targeted, (ii) emotional worries, anxieties and feelings of hostility, spying, and teasing, and (iii) coping mechanisms that maintained children’s avoidant behaviours. Consistent with the threat anticipation cognitive model of delusions (Freeman et al., 2007), persistently mistrustful children reported frequent peer victimization and hostile attributional bias. Instances of unfounded paranoia were rare but not absent. There was moderate convergent validity between interviewer ratings and the SMS (k=.49, p<.001). The coding scheme discriminated trusting and mistrustful children accurately. Discussion Interviews with trusting and persistently mistrustful children are necessary in verifying unfounded childhood suspicions. Complementing self-report measures of suspiciousness, thematic codes from this study have the potential to screen for persistent and strongly held suspicions that may develop into delusions later in life.


1
Child and Adolescent Mental Health Center, Mental Health Services, The Capital Region of Denmark; 2 Aarhus University Hospital; 3 University of Copenhagen; 4 Maastricht University Medical Centre Background: Self-report measures are often used to assess psychotic experiences (PE) in large-scale epidemiological samples, and have contributed substantially to our knowledge on PE. However, different self-report PE (PE-S) measures have yielded particularly wide-spread prevalence-estimates of PE ranging from 21-66 % in 7-13 year old children, whereas interview based measures of PE (PE-I) vary less (10 -23 %). Especially PE-S have been criticized for being over-inclusive and not capturing the essence of low-grade psychosis. The current study is the first large-scale study to examine the psychometric properties of a PE-S measure in children, and the first to compare the clinical correlates of PE-S and PE-I in the same sample. Methods: As part of the general population Copenhagen Child Cohort 2000 studies, 1571 children aged 11-12 years were independently assessed for both PE-I and PE-S. PE-I were assessed by trained professionals with 22 items on hallucinations and delusions from the Kiddie Schedule for Affective Disorders and Schizophrenia present and life-time version (Kiddie-SADS-PL). PE-S were assessed by 10 questions covering hallucinations, delusions and subjective thought disturbances ever in life, forming a new section of the diagnostic interview, the Development and Well Being Questionnaire (DAWBA). We assessed the psychometric properties of PE-S, using PE-I as the "goldstandard". We analyzed the association between PE-S and emotional and neurodevelopmental DSM-IV disorders of the child as well as a history of psychotic disorders in 1st degree family members. Both have previously been examined in previous studies of the current cohort, and were significantly associated with PE-I. Results: The prevalence of PE-S was higher compared to PE-I, 28.1% and 10.2% respectively. The predictive values of any type of PE-S for any PE-I were: sensitivity = 73.8%, specificity = 77.1%, positive predictive value = 26.8% and negative predictive value = 96.3%. The association between PE and mental health disorders and a family history of psychotic disorders yielded slightly lower odds ratios (OR) for PE-S compared to PE-I. However, the associations remained statistically significant and had overlapping confidence intervals: For any emotional or neurodevelopmental DSM-IV disorder: PE-I OR 3.3 (CI95% 2.3-4.8) and PE-S OR 2.7 (CI95% 2.1-3.6), for a 1st degree family history of psychotic disorder; PE-I OR 4.9 (CI95% 1.9-12.5) and PE-S OR 2.6 (CI95% 1.1-6.3). Discussion: PE-S were almost 3 times more likely to be reported, compared to observer-rated PE-I. However, the associations with unfavorable clinical correlates were only slightly attenuated for PE-S when compared to PE-I. The study confirmed that PE-S are clinically relevant, and the DAWBAsection proved valuable as a screening tool for PE in the pre-adolescent general population.

S30. UNDERSTANDING THE NATURE OF CHILDHOOD SUSPICIOUSNESS: A QUALITATIVE STUDY
Keri Wong* ,1 1 University of Cambridge Background: Paranoia exists on a continuum of severity in adult patient populations and more recently it has been found to exist in children and adolescents in the general population. Childhood paranoia, assessed by the Social Mistrust Scale (SMS), has been found to be related to both internalising and externalising problem behaviours (Wong, Freeman & Hughes, 2014); however, the nature of why children's suspicions are related to psychosocial functioning remains unexamined. The current qualitative study addresses this gap by following up the original 2014 sample to examining the nature of children's suspicions using thematic analysis. By giving voice to children and adolescents, I will discuss: 1) children's definition of trust and mistrust more broadly 2) the common themes generated from interview questions about children's suspicions in relation to baseline self-reported levels of suspiciousness on the Social Mistrust Scale (SMS) and 3) other developmental psychosocial factors contributing to childhood suspicions. This study is also the first study to address whether or not children's suspicions are valid, or grounded in reality, using interviewer ratings and child self-report measures of mistrust. Methods: 118 trusting and persistently mistrustful children from the UK (n=40) and Hong Kong (n=78) were matched and followed-up at 6 and 12 months based on their self-reported levels of suspiciousness on the Social Mistrust Scale. Correlations and kappas were conducted to assess the stability and convergent validity between assessments. Thematic analysis was conducted on 95 (80%) randomly selected semi-structured interviews about mistrust. The coding scheme generated from this analysis was further tested on the remaining transcripts for discriminant validity. Results: Children's definition of trust was consistent with existing developmental literature. Commonly discussed topics related to mistrust, particularly school mistrust, included (i) experiences of bullying, concerns with popularity and the consequences of being targeted, (ii) emotional worries, anxieties and feelings of hostility, spying, and teasing, and (iii) coping mechanisms that maintained children's avoidant behaviours. Consistent with the threat anticipation cognitive model of delusions (Freeman et al., 2007), persistently mistrustful children reported frequent peer victimization and hostile attributional bias. Instances of unfounded paranoia were rare but not absent. There was moderate convergent validity between interviewer ratings and the SMS (k=.49, p<.001). The coding scheme discriminated trusting and mistrustful children accurately. Discussion: Interviews with trusting and persistently mistrustful children are necessary in verifying unfounded childhood suspicions. Complementing self-report measures of suspiciousness, thematic codes from this study have the potential to screen for persistent and strongly held suspicions that may develop into delusions later in life.

S31. BASIC SENSE OF SELF IN YOUTH AT HIGH RISK FOR DEVELOPING SCHIZOPHRENIA
Hadar Hazan* ,1 , Richard Linscott 1 , Elaine Reese 1 1 University of Otago Background: Phenomenological researchers argue that schizophrenia is first and foremost a disorder of the basic sense of self (also known as ipsity, minimal or core self), that is, of the immediate, pre-reflective, embodied sense of being immersed in the world. According to the self-disorder model, impairment of the basic sense of self precedes clinical symptoms and is independent of them. Therefore, we postulated that youth at high psychometric risk for developing schizophrenia would present an impairment in their basic sense of self, as measured by levels of ego strength, basic symptoms, and pronoun usage. Methods: Eighty undergraduate students aged 19-22 years (M = 20.83 years, SD = 1.28 years) completed the Schizotypal Personality Questionnaire (SPQ), Ego Strengths Questionnaire (ESQ), a self-report version of Schizophrenia Proneness Instrument (SPI-A), and four written narratives about personal and fictional experiences. Based on the SPQ scores, participants were allocated to either control (at or below the 84th percentile on all three subscales) or study group (above the 90th percentile on at least one subscales). To obtain the linguistic dimension of the pronouns usage in the written narratives, the essays were subjected to Linguistic Inquiry and Word Count (LIWC). Results: Compared to the control group, the high-risk group presented lower levels of ego strength, higher levels of basic symptoms, and used more personal pronouns and the they pronoun in narratives. Self-report on the SPI-A and ESQ correlated significantly with the objective lexical pattern of pronoun use: Lower ego strength correlated with greater use of they and more self-reported basic symptoms correlated with greater use of pronouns overall, personal pronouns, and the pronouns she and they. Ego strength had the most predictive power for group membership Discussion: In line with the hypotheses, there were significant differences between the schizotypy and the control groups in objective and subjective measures of basic sense of self. Subjective measures indicated a lower level of ego strength and higher levels of basic symptoms for the schizotypy group, as compared with the control group. Objective measures revealed a different lexical pattern with higher use of third-person and personal pronouns for the schizotypy group, as compared with the control group. Subjective (basic symptoms and ego strength) and objective measures significantly correlated with each other (pronoun use). Nevertheless, it is only the level of cognitive-perceptive disturbances that best predicted membership of the schizotypy group. Taken together, these results indicate a weak sense of basic self, namely a self-disorder, in a nonclinical population. Detection of self-disorder in the premorbid and prodrome stages of schizophrenia, paired with a suitable intervention, can help to prevent or at least minimize, the eruption of its active stage. In the future, it needs to be determined how these measures of self-disorder in non-clinical population can predict transition to schizophrenia and to other psychotic disorders. Furthermore, it would be valuable to test the distributions of measures of self-disorder in younger population from a more diverse background, such as high school students from a different socio-economic background. Lastly, it is possible to conclude that some impairment in the basic sense of self does exist in schizotypy. This is apparent across the measures of selfdisorder and suggests that there is a core feature that distinguishes schizotypes from non-schizotypes.

S32. ANXIETY IN THE DEVELOPMENT OF PSYCHOTIC EXPERIENCES IN CHILDREN AND ADOLESCENTS: A SYSTEMATIC REVIEW
Jessica Bird* ,1 , Felicity Waite 1 , Daniel Freeman 1 1 University of Oxford Background: Although traditionally separated in psychiatry, the overlap between psychosis and neurosis is becoming clear. It has been argued that emotional processes are not only a core component of psychotic experiences (PEs), but also have a causal role in symptom development. In particular, increasing evidence has highlighted anxiety may be especially important in the emergence of psychotic experiences. As the time when psychotic symptoms first emerge, understanding how anxiety influences their development in childhood and adolescence will inform early intervention. In this systematic review, we investigate the role of anxiety across the spectra of psychotic experiences in children and young people. We examine the available evidence whilst aiming to answer the questions of whether anxiety and psychotic experiences co-occur in young people and if anxiety plays a contributory causal role. Methods: A systematic literature search was conducted on PsychINFO, Medline, EMBASE, and Scopus (updated October 2017). Papers published in peer-reviewed journals were identified that investigated the relationship between anxiety and PEs in children and adolescents within both non-clinical and clinical populations. Twenty-three papers met inclusion criteria. The RTI item bank assessment framework for observational studies was used to evaluate the precision and risk of bias of each individual study.

Results:
The findings of this review demonstrated clear evidence for a consistent relationship between anxiety and psychotic experiences in