It was demonstrated that individuals at CHR report significantly more trauma and bullying than healthy controls. Further, those CHR subjects who experienced past trauma and bullying are more likely to have increased levels of depression and anxiety and a poorer sense of self. Importantly, higher levels of total childhood trauma were demonstrated to be associated with lower global role functioning .Second, Perkins et al. identified a multiplex blood assay that reliably distinguished participants at clinical high risk for psychosis from unaffected comparison subjects and predicted which CHR subjects are likely to transition to an acute psychotic disorder, confirming that inflammation, oxidative stress, and dysregulation of hypothalamic-pituitary axes may be prominent in the earliest stages of psychosis . The classifier included 15 analytes , demonstrating that unique profiles of inflammatory plasma analytes can be used to differentiate between patient and control groups. Finally, Walker et al. demonstrated evidence of heightened cortisol secretion in CHR individuals also indicating nonspecific associations between cortisol levels and symptom severity, as well as symptom progression. Thus, adding to accumulating evidence regarding role of HPA activity in prediction of conversion to psychosis. However, despite these relevant discoveries,mobile vertical grow rack it has yet to be determined whether inflammation may serve as a biological mediator between childhood trauma and CHR clinical outcomes.
A robust body of literature supports the hypothesis that exposure to early life stress, such as childhood trauma, may uncover genetic and epigenetic vulnerabilities that influence neurobiological responses to stress, including activation of the HPA-axis and associated immune system response. Further, individuals diagnosed with psychosis have a higher prevalence of exposure to childhood trauma, as well as evidence of inflammatory dysregulation. It is therefore reasonable to suggest that experience of maltreatment in childhood may lead to changes in neurobiological response to stress, as measured by markers of inflammation, and that this response is associated with the onset of various mental illnesses in adulthood, including psychosis. However, to our knowledge, no studies to date have evaluated the relationships between childhood trauma, inflammation, and clinical outcomes in individuals at clinical high risk for psychosis. Data for this project was derived from The North American Prodrome Longitudinal Study , an 8-site observational study of the predictors and mechanisms of conversion to psychosis in persons meeting the Criteria of Prodromal States . The overall NAPLS 2 cohort included 765 clinical high-risk and 280 demographically similar unaffected comparison subjects aged between 12 and 35. The study was approved by the Institutional Review Board at each site, and each subject provided written informed consent or assent, with a parent or guardian also consenting for minor subjects. The plasma analysis for biomarkers included a smaller subset of this larger subject pool. This subsample differs from the larger NAPLS sample in that a higher proportion of CHR subjects included are known to have progressed to psychosis , whereas the remaining CHR subjects had been followed 2 years and not progressed to psychosis during that time . The unaffected comparison subjects did not meet CHR criteria or have a history of a psychotic disorder and were chosen to be demographically similar to the CHR subjects. Individuals at CHR had to be between 12 and 35 years old and meet diagnostic criteria for a prodromal syndrome as per the COPS criteria or if under 19, meet criteria for schizotypal personality disorder .
Control subjects could not meet criteria for any prodromal syndrome, any current or past psychotic disorder or a Cluster A personality disorder diagnosis and could not have a family history of any psychotic disorder or any other disorder involving psychotic symptoms. UC subjects could not be currently using psychotropic medication. Participants were excluded if they met criteria for current or lifetime Axis I psychotic disorder, including affective psychoses, IQ < 70, or had a history of a central nervous system disorder, substance dependence in the past 6 months, or if the diagnostic prodromal symptoms were clearly caused by an Axis I disorder. Other non-psychotic DSM-IV disorders were not exclusionary , as long as the disorder did not account for the individual’s prodromal symptoms. Use of antipsychotics was not an exclusion provided there was clear evidence that prodromal symptoms were present when the medication was started. The SCID was used to rule out the presence of psychosis. The SIPS and the SOPS were used to assess COPS criteria and severity of attenuated positive symptoms and negative symptoms . The SOPS is a 19-item scale designed to measure the severity of prodromal symptoms. The SOPS contains four sub-scales for Positive, Negative, Disorganization and General Symptoms. The five positive symptoms are P1-unusual thought content/delusional ideas, P2- suspiciousness/persecutory ideas, P3-grandiose ideas, P4-perceptual abnormalities, P5- disorganized communication. The six negative symptoms are N1-social anhedonia, N2-avolition, N3-expression of emotion, N4-experience of emotion and self, N5-ideational richness, N6- occupational functioning. The four disorganization symptoms are D1-odd behavior or appearance, D2-bizarre thinking, D3- trouble with focus and attention, D4-impairment in personal hygiene.
The four general symptoms are G1-sleep disturbance, G2-dysphoric mood, G3-motor disturbances, G4-impaired tolerance to normal stress. Positive symptoms are rated on a scale from 0 to 6 . Negative, disorganized, and general symptoms are rated on a scale from 0 to 6 . All clinical evaluations were completed by staff with extensive training in clinical interviewing and certified in administering the SIPS assessments after achieving good to excellent inter-rater reliability . Clinical outcome at each follow-up assessment was determined in the following way: remission ; symptomatic ; prodromal progression and psychotic . Transition to psychosis was determined by meeting the Presence of Psychotic Symptoms criteria. Transition criteria is that at least one of the five SOPS positive symptoms reached a psychotic level of intensity for a frequency of ≥ 1 hour per day for 4 days per week during the past month or that symptom seriously impacted functioning .Plasma analysis reported here was conducted in March 2012. Plasma Collection Blood samples used in this analysis were drawn at the baseline visit in Becton Dickenson P100 blood collection tubes with ethylene diamine tetra-acetic acid as anticoagulant, proprietary protein stabilizers, and a mechanical separator. All samples were processed within 120 minutes and stored at −80°C until analysis. Plasma Assay Plasma samples were sent on dry ice to Myriad Rules Based Medicine, a biomarker testing laboratory that has maintained clinical laboratory improvement amendments accreditation by the Commission on Office Laboratory Accreditation since 2006. Samples were analyzed with the Human Discovery Map assay, a Luminex bead-based multiplex immunoassay that included 185 analytes involved in hormonal responses, inflammation, growth, oxidative stress, and metabolism, all according to Rules-Based Medicine standard operating procedures. Technicians ran assays without knowledge of clinical status of the subjects. Highly correlated networks of inflammatory markers will be identified. Exploratory Factor Analysis was used to explore whether highly correlated networks of inflammatory markers could be identified from the 117 analytes in the present study. EFA was chosen over Confirmatory Factor Analysis ,mobile vertical growing racks as there is no defined theory regarding the number of factors or which factors theories might best fit an a-priori model of inflammatory networks. In order to limit the potential subjectiveness of EFA, we completed a systematic application of theoretical principles to latent variables, factor reduction, and construction . Firstly, the data was analyzed to determine suitability for factor analysis. A correlation matrix will be used to display the relationships between variables for inspection of correlation coefficients over 0.3. Hair J, Anderson RE, Tatham RL, and WC. categorized these loadings using another rule of thumb as ±0.30=minimal, ±0.40=important, and ±.50=practically significant. If no correlations go beyond 0.30, then factor analysis will be reconsidered, only inflammatory markers known to be associated with childhood trauma from existing research will be used in subsequent analyses. Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Bartlett’s Test of Sphericity was used to assess the suitability of the respondent data for factor analysis. The KMO index is recommended when the cases to variable ratio is less than 1:5. The KMO index ranges from 0 to 1, with 0.50 considered suitable for factor analysis . Further, the Bartlett’s Test of Sphericity should be significant for factor analysis to be suitable to utilize . If the data is not suitable for factorability analyses, EFA will stop after this step and apriori identified analytes, including Perkins et al. 15-Analyte Index will be used in subsequent correlation and mediation analyses. Otherwise, principal components analysis will be used to extract factors as no priori theory or model exists to guide this analysis . Thirdly, multiple extraction techniques will be used for factor extraction including: Kaiser’s criteria for eigenvalue’s > 1 , the Scree plot test , and parallel analysis .
Each of these tests will be performed and extracted factors evaluated to determine the most consistent and parsimonious number of factors. Fourthly, factor rotation will be used in order to maximize high item loadings and minimize low item loadings, therefore producing a more interpretable and simplified solution . Although there are two common rotation techniques: orthogonal rotation and oblique rotation, oblique rotation will be used in order to account for factor correlations, which is more accurate for research involving human behaviors and preferred when data does not meet priori assumptions . Finally, factors will be labeled. The labelling of factors is a subjective, theoretical, and inductive process . Factors will be operationalized and descriptively labelled according to constructs that reflect theoretical concepts in inflammatory research.There will be a significant positive relationship between childhood trauma and psychosis risk symptom severity and a significant negative relationship between childhood trauma and global/social/role functioning for CHR subjects. Hypothesis 3b. There will be a significant positive relationship between inflammatory analytes, childhood trauma, and psychosis risk symptom severity, as well as a significant negative relationship between inflammatory analytes and global/social/role functioning in CHR subjects. Partial Pearson product correlation analyses were used to evaluate the relationships between total trauma, inflammatory analytes, SOPS, GAF, GFR, and GF. Differences in demographic variables, substance use, psychotropic medication, and blood sampling time were controlled for in analyses. Inflammation will partially mediate the relationship between childhood trauma and psychosis-risk symptom severity, as well as between childhood trauma and functioning.The 3-step Baron and Kenny mediation analysis was conducted to determine if the mediator is caused by the initial IV and is a cause of the DV , the initial IV loses its significance once the mediator is included in the model. More explicitly, first, simple linear regression was used to confirm the relationship between the independent variable, total childhood trauma, and the dependent variable, psychosis risk symptom severity OR functioning. Second, simple linear regression was used to confirm the relationship of childhood trauma and inflammatory analytes defined in Hypothesis 2a and 3b. Third, a final linear regression was used to confirm the significance of the relationship between the inflammatory analytes and psychosis risk symptom severity, or functioning in the presence of childhood trauma, as well as confirm the insignificance or the relationship between the childhood trauma, psychosis risk symptom severity , in the presence of the mediator . Significant associations from hypotheses 3a and 3b will be used to determine the most reasonable clinical outcomes to be used as dependent variables and inflammatory analytes to be used as mediators in subsequent models.Multivariate Analysis of Covariance with Bonferroni Post Hoc Testing and Chi-squared tests were used to explore the between subjects effects of conversion status and trauma history on clinical, functional, and inflammatory analytes. Homogeneity assumptions were evaluated at an alpha level of .001 using Box’s M test of homogeneity of covariance and Levene’s homogeneity test. Wilk’s criterion was used as the omnibus test statistic.The z-score corrected inflammatory assay data was screened for univariate outliers and no missing data was identified. The KMO index Measure of Sampling Adequacy was greater than 0.50 and Bartlett’s Test of Sphericity was not significant indicating that factor analyses would not be suitable to utilize. Further, the inflammatory analytes did not meet the correlation factorability criteria, with correlations less than 0.3, suggesting factorability was not reasonable. As a result, highly correlated networks of inflammatory analytes were not identifiable in this dataset.