Temperament and character dimensions of the relatives of schizophrenia patients and controls: The relationship between schizotypal features and personality

Magical thinking in individuals with high polygenic risk for schizophrenia but no non-affective psychoses-a general population study

A strong genetic background for psychoses is well-established. Most individuals with a high genetic risk for schizophrenia, however, do not develop the disorder. We investigated whether individuals, who have a high genetic risk for schizophrenia but no non-affective psychotic disorders, are predisposed to develop milder forms of deviant thinking in terms of magical thinking. Participants came from the population-based Young Finns Study (n = 1292). The polygenic risk score for schizophrenia (PRS) was calculated on the basis of the most recent genome-wide association study (GWAS). Psychiatric diagnoses over the lifespan were collected up to 2017 from the registry of hospital care. Magical thinking was evaluated with the Spiritual Acceptance Scale (e.g., beliefs in telepathy, miracles, mystical events, or sixth sense) of the Temperament and Character Inventory in 1997, 2001, and 2012 (participants were 20-50-year-olds). We found that, among those who did not develop non-affective psychotic disorders, high PRS predicted higher magical thinking in adulthood (p = 0.001). Further, PRS predicted different developmental courses: a low PRS predicted a steady decrease in magical thinking from age 20 to 50 years, while in individuals with high PRS the decrease in magical thinking ceased in middle age so that their level of magical thinking remained higher than expected for that age. These findings remained when controlling for sex, childhood family environment, and adulthood socioeconomic factors. In conclusion, if high PRS does not lead to a non-affective psychotic disorder, it predicts milder forms of deviant thinking such as elevated magical thinking in adulthood, especially in middle age. The finding enhances our understanding of different outcomes of high genetic psychosis risk.

Integrating trauma, self-disturbances, cognitive biases, and personality into a model for the risk of psychosis: a longitudinal study in a non-clinical sample

The hypothesis of the psychosis continuum enables to study the mechanisms of psychosis risk not only in clinical samples but in non-clinical as well. The aim of this longitudinal study was to investigate self-disturbances (SD), a risk factor that has attracted substantial interest over the last two decades, in combination with trauma, cognitive biases and personality, and to test whether SD are associated with subclinical positive symptoms (PS) over a 12-month follow-up period. Our study was conducted in a non-clinical sample of 139 Polish young adults (81 females, age M = 25.32, SD = 4.51) who were selected for frequent experience of subclinical PS. Participants completed self-report questionnaires for the evaluation of SD (IPASE), trauma (CECA.Q), cognitive biases (DACOBS) and personality (TCI), and were interviewed for subclinical PS (CAARMS). SD and subclinical PS were re-assessed 12 months after baseline measurement. The hypothesized model for psychosis risk was tested using path analysis. The change in SD and subclinical PS over the 12-month period was investigated with non-parametric equivalent of dependent sample t-tests. The models with self-transcendence (ST) and harm avoidance (HA) as personality variables were found to be well-fitted and explained 34% of the variance in subclinical PS at follow-up. Moreover, we found a significant reduction of SD and subclinical PS after 12 months. Our study suggests that combining trauma, cognitive biases, SD and personality traits such as ST and HA into one model can enhance our understanding of appearance as well as maintenance of subclinical PS.

Non-Suicidal Self-Injury Among Incarcerated Adolescents: Prevalence, Personality, and Psychiatric Comorbidity

Introduction: Incarcerated adolescents represent a risk group for non-suicidal self-injury (NSSI), but research on this population has been limited and no studies have been conducted in Russia. To address this deficit, this study examined NSSI and the factors associated with it among youth in a juvenile correctional facility in Russia. Methods: NSSI and psychopathology were assessed using a psychiatric interview and self-report questionnaire in 368 incarcerated male adolescents aged 14-19 years (mean age 16.4 years, S.D. 0.9) from Northern Russia. Results: 18.2% (N = 67) of the study participants had a history of NSSI and also had higher rates of anxiety, post-traumatic stress disorder (PTSD), depression, community violence exposure and scored higher on most of the Youth Self-Report problem scales. In addition, 31.3% of the NSSI group reported previous suicidal ideation and had thought about a specific suicide method compared to 12.0% in the No-NSSI group. Adolescents with NSSI also differed significantly from the No-NSSI group on self-directedness (lower) and self-transcendence (higher) personality traits. Conclusion: NSSI is common in incarcerated adolescents in Russia and is associated with extensive psychiatric comorbidity, suicidal ideation and specific personality traits.

Personality Traits as Markers of Psychosis Risk in Kenya: Assessment of Temperament and Character

Specific personality traits have been proposed as a schizophrenia-related endophenotype and confirmed in siblings at risk for psychosis. The relationship of temperament and character with psychosis has not been previously investigated in Africa. The study was conducted in Kenya, and involved participants at clinical high-risk (CHR) for psychosis (n = 268) and controls (n = 251), aged 15–25 years. CHR status was estimated using the Structured Interview of Psychosis-Risk Syndromes (SIPS) and the Washington Early Psychosis Center Affectivity and Psychosis (WERCAP) Screen. Student’s t-tests were used to assess group differences on the Temperament and Character Inventory (TCI). Neurocognitive functioning, stress severity, and substance use were correlated with the TCI, correcting for psychosis severity. CHR participants were more impulsive (ie, higher novelty seeking [NS]) and asocial (ie, lower reward dependence) than controls. They were also more schizotypal (ie, high self-transcendence [ST] and lower self-directedness [SD] and cooperativeness [CO] than controls). CO was related to logical reasoning, abstraction, and verbal memory. Stress severity correlated with high HA and schizotypal character traits. Lifetime tobacco use was related to NS, and lifetime marijuana use to high NS, low SD and high ST. Temperament and character of Kenyan CHR youth is similar to that observed in schizophrenia. Psychosis risk in Kenya is associated with impulsive, asocial, and schizotypal traits. CHR adolescents and young adults with schizophrenia-specific personality traits may be most at risk for developing a psychotic disorder and to require early intervention to improve outcomes.

Relationship of self-transcendence traits with in vivo dopamine D2/3 receptor availability and functional connectivity: An [18 F]fallypride PET and fMRI study

Genetic research has implicated dopamine neurotransmission in the expression of the self-transcendence trait in humans. However, molecular imaging of dopaminergic markers is undocumented in relation to this personality trait. In this multimodal imaging study, we first investigated the relationship between the self-transcendence trait and in vivo dopamine D_2/3 receptor availability using [¹⁸ F]fallypride positron emission tomography (PET). We next conducted seed-based functional connectivity analyses using resting-state functional magnetic resonance imaging (rs-fMRI) data with regions derived from the PET analysis as seeds to explore the functional significance of D_2/3 receptor availability foci associated with the self-transcendence trait. Twenty-one healthy subjects underwent high-resolution PET with [¹⁸ F]fallypride and a subset of 18 subjects also completed 3-Tesla rs-fMRI. The Temperament and Character Inventory was used to measure the self-transcendence trait. A voxel-based whole brain analysis revealed that the [¹⁸ F]fallypride binding potential (BP_ND ) within the cluster of the left insula was significantly positively correlated with self-transcendence trait scores. A region-of-interest analysis also showed a significant positive correlation between self-transcendence and [¹⁸ F]fallypride BP_ND in the left insula. The exploratory [¹⁸ F]fallypride BP_ND seed-based rs-fMRI analysis showed that the functional connectivity from the left insula seed to the prefrontal cortices (including the inferior frontal region) was negatively associated with self-transcendence trait scores. The results of the present study suggest that D_2/3 receptor-mediated neurotransmission in the left insula may constitute a significant neurobiological factor in the self-transcendence trait. The negative associations between BP_ND seed-based functional connectivity and self-transcendence trait scores may suggest reduced prefrontal control in this personality trait.

Associations Of Personality Traits With The Capacity-Performance Discrepancy Of Functional Outcome In Patients With Schizophrenia

OBJECTIVE

Functional capacity, which indicates one's ability to perform everyday living tasks, contributes to real-world functional performance in patients with schizophrenia. However, functional capacity is sometimes not comparable with functional performance in clinical settings. We hypothesized that specific personality traits are related to this capacity-performance discrepancy of functional outcome.

METHODS

The measures in this study were the UCSD Performance-based Skills Assessment Brief (UPSA-B) for functional capacity, the Social Functioning Scale (SFS) for functional performance, and the Temperament and Character Inventory-140 (TCI-140) for personality traits. A total of 94 stable outpatients with schizophrenia were divided into four groups based on combinations of their UPSA-B and SFS cut-off points, as follows: a high capacity and high performance (HH) group, a high capacity but low performance (HL) group, a low capacity but high performance (LH) group, and a low capacity and low performance (LL) group.

RESULTS

There were no significant differences in demographics among the four groups. The LH group showed a significantly lower harm avoidance level than the LL group. The HL group showed a significantly lower persistence level than the HH group.

CONCLUSION

Lower harm avoidance may enhance functional performance, and lower persistence can limit functional performance, regardless of the primary levels of functional capacity in patients with schizophrenia. Novel and individualized psychosocial treatments considering the individual's personality traits seem to be helpful for maximizing their functional performance in the community.

Psychiatric framing affects positive but not negative schizotypy scores in psychology and medical students

When testing risk for psychosis, we regularly rely on self-report questionnaires. Yet, the more that people know about this condition, the more they might respond defensively, in particular with regard to the more salient positive symptom dimension. In two studies, we investigated whether framing provided by questionnaire instructions might modulate responses on self-reported positive and negative schizotypy. The O-LIFE (UK study) or SPQ (New Zealand study) questionnaire was framed in either a "psychiatric", "creativity", or "personality" (NZ only) context. We tested psychology students (without taught knowledge about psychosis) and medical students (with taught knowledge about psychosis; UK only). We observed framing effects in psychology students in both studies: positive schizotypy scores were lower after the psychiatric compared to the creativity instruction. However, schizotypy scores did not differ between the creativity and personality framing conditions, suggesting that the low scores with psychiatric framing reflect defensive responding. The same framing effect was also observed in medical students, despite their lower positive schizotypy scores overall. Negative schizotypy scores were not affected by framing in either study. These results highlight the need to reduce response biases when studying schizotypy, because these might blur schizotypy-behaviour relationships.

Assessment of Cognition and Personality as Potential Endophenotypes in the Western Australian Family Study of Schizophrenia

Phenotypic heterogeneity is a major barrier to understanding the genetic architecture underlying schizophrenia. Incorporating endophenotypes is one way to reduce heterogeneity and facilitate more powerful genetic analysis. Candidate endophenotypes require systematic assessment against endophenotype criteria, and a ranking of their potential utility for genetic analysis. In this study we assess 20 cognitive and personality measures in a sample of 127 families with at least 2 cases of schizophrenia per family (n = 535) plus a set of 30 control families (n = 121) against 4 endophenotype criteria: (a) be associated with the illness but not be a part of its diagnosis, (b) be heritable, (c) co-segregate with the illness in families, and (d) be found in unaffected relatives at a higher rate than in the general population. The endophenotype ranking score (endophenotype ranking variable [ERV]) was used to rank candidate endophenotypes based on their heritability and genetic correlation with schizophrenia. Finally, we used factor analysis to explore latent factors underlying the cognitive and personality measures. Evidence for personality measures as endophenotypes was at least equivalent to that of the cognitive measures. Factor analysis indicated that personality and cognitive traits contribute to independent latent dimensions. The results suggest for this first time that a number of cognitive and personality measures are independent and informative endophenotypes. Use of these endophenotypes in genetic studies will likely improve power and facilitate novel aetiological insights.

Schizotypy-Independent and Schizotypy-Modulated Cognitive Impairments in Unaffected First-Degree Relatives of Schizophrenia-spectrum Patients

Objective

The aim of the study was to compare the neurocognitive profile of unaffected first-degree relatives of schizophrenia patients with control individuals, controlling for different schizotypal traits.

Method

One hundred and fifteen adult unaffected first-degree relatives of schizophrenia-spectrum patients and 122 controls were tested for schizotypy with the Schizotypal Personality Questionnaire. They also underwent a thorough neurocognitive assessment with a range of tasks covering several aspects of executive functioning. Between-group differences in cognition were examined first with multivariate analysis of variance and then with a series of multivariate analyses of covariance, including the schizotypal dimensions as covariates.

Results

The relatives had higher scores on all schizotypal dimensions compared with controls and poorer planning, problem solving, strategy formation and working memory, irrespective of schizotypal traits. They also scored lower in executive working memory and verbal fluency. The difference in executive working memory was sensitive to the effects of paranoid and negative schizotypy (both dimensions abolished the between-group difference) whereas the difference in verbal fluency was sensitive only to the effects of paranoid schizotypy. Neither cognitive-perceptual nor disorganized schizotypy accounted for any differences in neurocognition between relatives and the controls.

Conclusions

Impairments in planning, problem solving, strategy formation and working memory are "core" impairments in the schizophrenia-spectrum, possibly due to high heritability effects in these functions. Impairments in executive working memory and verbal fluency are associated with paranoid and negative schizotypy, possibly due to alterations in a common fronto-temporo-parietal neural network.

Personality dimensions in schizophrenia: A family study

Studies have demonstrated that personality traits differ in schizophrenia patients and family members compared to controls, suggesting familial risk. This study evaluated personality traits in a family study of schizophrenia, as well as the relationship between personality traits and symptoms and social functioning in schizophrenia patients. Thirty-two schizophrenia patients, 28 adult non-psychotic relatives, and 27 community controls completed the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ). Schizophrenia patients differed on many dimensions of the DAPP-BQ compared to controls and/or relatives: affective lability, anxiousness, callousness, conduct problems, cognitive dysregulation, identity problem, intimacy, insecure attachment, low affiliation, narcissism, oppositionality, restricted expression, self-harm, submissiveness, and suspiciousness. No differences were found between relatives and controls. Furthermore, in schizophrenia patients, associations were found between personality and particularly general symptoms, as well as social functioning. Personality traits can be conceptualized as an extended phenotype in schizophrenia patients.

Schizotypal and affective traits in the offspring of antenatally depressed mothers - Relationship to family history of psychosis in the Northern Finland 1966 Birth Cohort

BACKGROUND

Maternal depression is relatively common during pregnancy. However, follow-ups of the adult offspring of antenatally depressed mothers are scarce. Previously we found the risk of schizophrenia to be higher in the adult offspring with antenatally depressed mothers and parents with psychosis than in subjects with only one or neither of these risk factors. The aim was to study whether the risk of schizotypal or affective traits differ among adult offspring with antenatally depressed mothers with or without a parental history of psychosis when compared with offspring without antenatally depressed mothers and without parental psychosis.

METHODS

In the general population-based Northern Finland 1966 Birth Cohort (NFBC 1966), the mothers of the cohort members were asked at mid-gestation whether they felt depressed. Parental psychosis (Familial Risk, FR) was detected using the Finnish Care Register for Health Care. In the 31-year field study, seven psychometric questionnaires surveyed schizotypal and affective traits in the offspring. The final sample included 4928 individuals (2203 males).

RESULTS

There were no statistically significant differences in mean scores on the schizotypal and affective scales between offspring with and without antenatally depressed mothers, or between subjects with and without parental psychosis. The scores were not highest in the subjects with both maternal antenatal depressed mood and FR.

CONCLUSION

Surprisingly, maternal depressed mood during pregnancy was unlikely to increase the risk of schizotypy or affective traits in adult offspring, and not even with parental psychosis (FR) in this general population-based birth cohort with about 5000 subjects.

Parkinsonian motor impairment predicts personality domains related to genetic risk and treatment outcomes in schizophrenia

Identifying endophenotypes of schizophrenia is of critical importance and has profound implications on clinical practice. Here we propose an innovative approach to clarify the mechanims through which temperament and character deviance relates to risk for schizophrenia and predict long-term treatment outcomes. We recruited 61 antipsychotic naïve subjects with chronic schizophrenia, 99 unaffected relatives, and 68 healthy controls from rural communities in the Central Andes. Diagnosis was ascertained with the Schedules of Clinical Assessment in Neuropsychiatry; parkinsonian motor impairment was measured with the Unified Parkinson’s Disease Rating Scale; mesencephalic parenchyma was evaluated with transcranial ultrasound; and personality traits were assessed using the Temperament and Character Inventory. Ten-year outcome data was available for ~40% of the index cases. Patients with schizophrenia had higher harm avoidance and self-transcendence (ST), and lower reward dependence (RD), cooperativeness (CO), and self-directedness (SD). Unaffected relatives had higher ST and lower CO and SD. Parkinsonism reliably predicted RD, CO, and SD after correcting for age and sex. The average duration of untreated psychosis (DUP) was over 5 years. Further, SD was anticorrelated with DUP and antipsychotic dosing at follow-up. Baseline DUP was related to antipsychotic dose-years. Further, ‘explosive/borderline’, ‘methodical/obsessive’, and ‘disorganized/schizotypal’ personality profiles were associated with increased risk of schizophrenia. Parkinsonism predicts core personality features and treatment outcomes in schizophrenia. Our study suggests that RD, CO, and SD are endophenotypes of the disease that may, in part, be mediated by dopaminergic function. Further, SD is an important determinant of treatment course and outcome.

Comorbidity of schizophrenia and social phobia - impact on quality of life, hope, and personality traits: a cross sectional study

OBJECTIVE

The purpose of the study was to explore whether the comorbidity of social phobia affects symptoms severity, positive and negative symptoms, self-stigma, hope, and quality of life in patients with schizophrenia spectrum disorders.

METHODS

This is a cross-sectional study in which all participants completed the Internalized Stigma of Mental Illness (ISMI) scale, Adult Dispositional Hope Scale (ADHS), Liebowitz Social Anxiety Scale (LSAS), Beck Anxiety Inventory (BAI), Beck Depression Inventory-II (BDI-II), Positive and Negative Syndrome Scale (PANSS), Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), Temperament and Character Inventory - Revised (TCI-R), and the demographic questionnaire. The disorder severity was assessed both by a psychiatrist (Clinical Global Impression Severity - the objective version [objCGI-S] scale) and by the patients (Clinical Global Impression Severity - the subjective version [subjCGI-S] scale). The patients were in a stabilized state that did not require changes in the treatment. Diagnosis of schizophrenia, schizoaffective disorder, or delusional disorder was determined according to the International Classification of Diseases 10th Revision (ICD-10) research criteria. A structured interview by Mini International Neuropsychiatric Interview was used to confirm the diagnosis.

RESULTS

The study included 61 patients of both genders. Clinically, the patients with comorbid social phobia had the earlier onset of the illness, more severe current psychopathology, more intense anxiety (general and social), and higher severity of depressive symptoms. The patients with comorbid social phobia showed the significantly lower quality of life compared to the patients without this comorbidity. The patients with comorbid social phobia also had a statistically lower mean level of hope and experienced a higher rate of the self-stigma. They also exhibited higher average scores of personality trait harm avoidance (HA) and a lower score of personality trait self-directedness (SD).

CONCLUSION

The study demonstrated differences in demographic factors, the severity of the disorder, self-stigma, hope, HA, and SD between patients with schizophrenia spectrum disorders with and without comorbid social phobia.

Depression and anxiety mediate the relationship between temperament and character and psychotic-like experiences in healthy subjects

In this study we examined the hypothesis that depression and anxiety may mediate the relationship between personality traits and both positive and negative psychotic-like experiences (PLEs) in healthy adults. The Community Assessment of Psychic Experiences (CAPE) scale, Temperament and Character Inventory (TCI), Beck Depression Inventory (BDI) and State and Trait Anxiety Inventory (STAI) were administered to 492 healthy individuals. Multiple stepwise regression and mediation analyses were performed to examine whether depressive and anxiety symptoms influence the relationship between the TCI dimensions and positive and negative PLEs. Self-transcendence, persistence, novelty-seeking and self-directedness significantly predicted positive PLEs; self-directedness and harm avoidance were predictable for negative PLEs. Self-transcendence, self-directedness, persistence and harm avoidance also predicted the distress caused by positive PLEs, whereas self-directedness and harm avoidance predicted distress raised by negative PLEs. Depressive symptoms and the state of anxiety partially mediated the linkage between self-directedness and positive PLEs, and between self-directedness, harm avoidance and negative PLEs. Our findings confirm that the personality pattern influences both positive and negative PLEs as well as distress caused by experiencing positive and negative PLEs, and they indicate that certain personality traits may influence the development of PLEs via the emotional pathway of heightened depression and anxiety.

How to tell a happy from an unhappy schizotype: personality factors and mental health outcomes in individuals with psychotic experiences

Objective:

It is unclear why some individuals reporting psychotic experiences have balanced lives while others go on to develop mental health problems. The objective of this study was to test if the personality traits of harm avoidance, self-directedness, and self-transcendence can be used as criteria to differentiate healthy from unhealthy schizotypal individuals.

Methods:

We interviewed 115 participants who reported a high frequency of psychotic experiences. The instruments used were the Temperament and Character Inventory (140), Structured Clinical Interview for DSM-IV, and the Oxford-Liverpool Inventory of Feelings and Experiences.

Results:

Harm avoidance predicted cognitive disorganization (β = 0.319; t = 2.94), while novelty seeking predicted bipolar disorder (β = 0.136, Exp [β]. = 1.146) and impulsive non-conformity (β = 0.322; t = 3.55). Self-directedness predicted an overall decrease in schizotypy, most of all in cognitive disorganization (β = -0.356; t = -2.95) and in impulsive non-conformity (β = -0.313; t = -2.83). Finally, self-transcendence predicted unusual experiences (β = 0.256; t = 2.32).

Conclusion:

Personality features are important criteria to distinguish between pathology and mental health in individuals presenting high levels of anomalous experiences (AEs). While self-directedness is a protective factor, both harm avoidance and novelty seeking were predictors of negative mental health outcomes. We suggest that the impact of AEs on mental health is moderated by personality factors.

Disintegration as an Additional Trait in the Psychobiological Model of Personality

Abstract. This meta-analytic study investigates the relations between Disintegration-like phenomena (i.e., various aspects of symptomatology with the prefix “schizo-,” both at the clinical and the subclinical level) and the traits of the Psychobiological Model of Personality (PBMP). The empirically based benchmark for assuming the distinctness of the trait Disintegration was .30. The sample included 26 manuscripts with 30 studies and 424 effect sizes. By computing inverse sampling variance weighted mean correlation coefficients under a random-effects assumption, the following associations were found between Disintegration and Harm Avoidance, Novelty Seeking, Reward Dependence, Persistence, Self-Directedness, Cooperativeness, and Self-Transcendence: .23, .04, −.15, −.02, −.23, −.16, and .17, respectively. Two variables were found to moderate the Disintegration-Self-Transcendence correlation. Despite the theoretical expectation and some empirical evidence that Self-Transcendence (and other character traits) should capture variations in Disintegration-like phenomena, our results suggest that schizo-type phenomena are not adequately covered by the PBMP.

Heritability and Familiality of Temperament and Character Dimensions in Korean Families with Schizophrenic Linkage Disequilibrium

Objective

Categorical syndromes such as schizophrenia may represent complexes of many continuous psychological structural phenotypes along several dimensions of personality development/degeneration. The present study investigated the heritability and familiality of personality dimensions in Korean families with schizophrenic linkage disequilibrium (LD).

Methods

We recruited 179 probands (with schizophrenia) as well as, whenever possible, their parents and siblings. We used the Temperament and Character Inventory (TCI) to measure personality and symptomatic dimensions. The heritability of personality dimensions in a total of 472 family members was estimated using Sequential Oligogenic Linkage Analysis Routines (SOLAR). To measure familiality, we compared the personality dimensions of family members with those of 336 healthy unrelated controls using analysis of variance (ANOVA) analysis.

Results

Three of the seven TCI variables were significantly heritable and were included in subsequent analyses. The three groups (control, unaffected first-degree relative, case) were found to significantly differ from one another, with the expected order of average group scores, for all heritable dimensions.

Conclusion

Despite several study limitations with respect to family recruitment and phenotyping, our results show that aberrations in several personality dimensions related to genetic-environment coactions or interactions may underlie the complexity of the schizophrenic syndrome.

Association between neurological soft signs, temperament and character in patients with schizophrenia and non-psychotic relatives

The heritability of schizophrenia and most personality traits has been well established, but the role of personality in susceptibility to schizophrenia remains uncertain. The aim of this study was to test for an association between personality traits and Neurological Soft Signs (NSS), a well-known biological marker of schizophrenia, in non-psychotic relatives of patients with schizophrenia. For this purpose, we evaluated the NSS scale and personality measured by the Temperament and Character inventory (TCI-R) in three groups of subjects: 29 patients with schizophrenia, 24 unaffected relatives and 37 controls. The results showed that patients with schizophrenia were more asocial (higher harm avoidance and lower reward dependence), more perseverative (higher persistence), and more schizotypal (lower self-directedness and cooperativeness, higher self-transcendence). The unaffected relatives showed higher harm avoidance, lower self-directedness and cooperativeness than the healthy controls. Higher NSS scores and sub-scores were found in patients and non-psychotic relatives compared with the controls. Among all the patients, total NSS scores were positively correlated with harm avoidance but negatively correlated with novelty seeking and persistence. Total NSS were also correlated with low scores on self-directedness and cooperativeness, which are indicators of personality disorder. Our results show that susceptibility to NSS and to schizophrenia are both related to individual differences in the temperament and character features in non-psychotic relatives of patients with schizophrenia. High harm avoidance, low persistence, low self-directedness and low cooperativeness contribute to both the risk of NSS and schizophrenia. These findings highlight the value of using both assessments to study high risk populations.

Psychometric properties of the Greek TCI-R and its clinical correlates: schizotypy and the self-regulation of affective and cognitive functioning

Background. The revised Temperament and Character Inventory (TCI-R) measures Cloninger’s psychobiological model of personality. The average effects of individual temperament and character traits have been associated with schizotypy and with impaired regulation of affect and cognition. We extended prior research by testing predictions about the association of specific multidimensional configurations of temperament and character traits on schizotypy, affect balance, and self-perceived cognitive functioning.

Method. A well-educated sample of native Greeks (N = 483), completed a new Greek translation of the TCI-R, as well as the Schizotypal Personality Questionnaire (SPQ), the Positive/Negative Affect Schedule (PANAS) and the Cognitive Failures Questionnaire (CFQ). The factor structure of the TCI-R was examined with exploratory and confirmatory tests. Associations between reported measures were examined with correlational and regression analyses.

Results. The TCI-R had good psychometric properties as expected from studies in other countries. As predicted, specific configurations of temperament and character were associated with schizotypy, negative affect balance, and cognitive lapses. The “Borderline/Explosive temperament” (high Novelty Seeking, high Harm Avoidance, low Reward Dependence), “Schizotypal/Disorganized character” (low Self-directedness, low Cooperativeness, high Self-transcendence), and “Low Ego Strength/Fragile” profile (high Harm Avoidance, low Persistence, low Self-Directedness) were each strongly associated with higher stereotypy, negative affect balance (low positive affect and high negative affect), and subjective cognitive lapses compared to their contrast groups.

Discussion. Multidimensional TCI profiles are strongly related to individual differences in schizotypy and self-reported regulation of affect and cognition. The Greek translation of the TCI-R is psychometrically sound and useful for clinical assessment and research.

Karolinska Scales of Personality, cognition and psychotic symptoms in patients with schizophrenia and healthy controls

BACKGROUND

Studies on both personality dimensions and cognition in schizophrenia are scarce. The objective of the present study was to examine personality traits and the relation to cognitive function and psychotic symptoms in a sample of patients with schizophrenia and healthy controls.

METHOD

In total 23 patients with schizophrenia and 14 controls were assessed with the Karolinska Scales of Personality (KSP). A broad cognitive test programme was used, including the Wechsler Adult Intelligence Scales, the Finger-Tapping Test, the Trail Making Test, the Verbal Fluency Test, the Benton Visual Retention Test, the Wisconsin Card Sorting Test and Rey Auditory Verbal Learning Test .

RESULTS

Compared with controls, the patients exhibited prominent elevations on KSP scales measuring anxiety proneness and neuroticism (P = 0.000005-0.0001), on the Detachment scale (P < 0.00009) and lower value on the Socialization scale (P < 0.0002). The patients also scored higher on the Inhibition of Aggression, Suspicion, Guilt and Irritability scales (P = 0.002-0.03) while the remaining five scales did not differ between patients and controls. KSP anxiety-related scales correlated with the Positive and Negative Symptoms Scale (PANSS) general psychopathology subscale. Cognitive test results were uniformly lower in the patient group and correlated with PANSS negative symptoms subscale. There was no association between KSP scale scores and PANSS positive or negative symptoms.

CONCLUSION

The patients revealed a highly discriminative KSP test profile with elevated scores in neuroticism- and psychoticism-related scales as compared to controls. Results support previous findings utilizing other personality inventories in patients with schizophrenia. Cognitive test performance correlated inversely with negative symptoms.

Personality features in ultra-high risk for psychosis: a comparative study with schizophrenia and control subjects using the Temperament and Character Inventory-Revised (TCI-R)

Several variables have been identified as risk factors for conversion to overt psychosis in ultra-high risk for psychosis (UHR) individuals. Although almost two-thirds of them do not experience a transition to psychosis, they still exhibit functional disabilities. Other subjective developmental features may be useful for a more precise identification of individuals at UHR. Avoidant behaviors are consistently reported in schizophrenia and in UHR individuals and may be the reflection of a pattern of personality. Thus, personality features in UHR individuals deserves further research. The objective of the present study was to compare temperament and character dimensions between UHR individuals, patients with schizophrenia and healthy controls. One hundred participants (25 UHR individuals, 25 schizophrenia patients and 50 control subjects) where evaluated with the Temperament and Character Inventory-Revised (TCI-R). Univariate ANOVAs followed by Bonferroni tests were used. UHR individuals and schizophrenia patients exhibited higher levels of Harm Avoidance (HA) when compared to control subjects. For HA1 Anticipatory worry vs Uninhibited optimism and HA4 Fatigability & asthenia, UHR and schizophrenia groups showed similar scores and both groups were higher compared to control subjects. With respect to Cooperativeness (CO), UHR and schizophrenia reported lower scores than control subjects, in particular CO2 Empathy vs Social disinterest and CO3 Helpfulness vs unhelpfulness. This study replicates and extends the consideration of HA as a psychopathological related endophenotype and gives us further information of the possible role of personality features in the expression of some of the social dysfunctions observed both in prodromal subjects and schizophrenia patients.

Cognitive biases mediate the relationship between temperament and character and psychotic-like experiences in healthy adults

Psychotic-like experiences (PLEs) are frequently reported in the general population. Healthy individuals reporting PLEs have a similar personality profile to people with psychosis; however, the mechanisms by which personality influences PLEs are unclear. This study tests the hypothesis that cognitive biases mediate the relationship between two dimensions of personality (i.e. temperament and character) and positive and negative PLEs. Two hundred and ninety-six healthy participants were assessed using the Community Assessment of Psychic Experiences scale, the Temperament and Character Inventory and the Davos Scale for Cognitive Biases. We performed multiple stepwise regression analysis and mediation analysis according to Baron and Kenny׳s method. Harm-avoidance and self-directedness personality dimensions significantly predicted PLEs frequency. High self-transcendence and lower cooperativeness predicted positive PLEs. Cognitive biases were significant mediators in relationships between temperament, character and both positive and negative PLEs. In particular, attention to threat and external attribution biases fully mediate the relationship between cooperativeness and positive PLEs. Other cognitive biases partially mediate the relationships between self-transcendence and positive PLEs and self-directedness, harm-avoidance and negative PLEs. Our study tentatively suggests that personality may influence PLEs via the cognitive bias pathway.

The relationship between temperament and character and subclinical psychotic-like experiences in healthy adults

BACKGROUND

Considerable data support phenomenological and temporal continuity between psychotic disorders and subclinical psychotic-like experiences (PLE's). Although numerous studies have found similar personality correlates for schizophrenia and schizotypal personality disorder patients, their unaffected first-degree relatives, and healthy adults characterized for schizotypal traits, no study has yet investigated personality correlates of PLE's measured by the Community Assessment of Psychic Experiences (CAPE). Our study sought to examine personality correlates of PLE's using the CAPE in healthy adults.

METHOD

The CAPE and temperament and character inventory (TCI) were administered to 415 healthy adults. Regressions examined links between TCI traits and overall PLE levels as well as positive and negative PLE's separately.

RESULTS

Consistent with past studies, lower self-directedness (SD) and reward dependence (RD) and higher self-transcendence (ST) and harm avoidance (HA) significantly predicted overall PLE levels. Higher ST and persistence (P) and lower SD significantly predicted higher levels of positive PLE's while lower SD and RD and higher HA, ST, and cooperativeness (C) predicted higher levels of negative PLE's.

CONCLUSIONS

Associations between TCI and PLE's using the CAPE are strikingly similar to past work in non-clinical and patient samples and provide additional support for phenomenological continuity between psychotic disorders and sub-syndromal psychotic symptoms.

Demographic features and premorbid personality disorder traits in relation to age of onset and sex in paranoid schizophrenia

Personality disorders in the premorbid period of schizophrenia and particularly in relation to age of onset and sex, seem to be a rather under-researched area. In the present study, 88 patients with paranoid schizophrenia were examined, regarding demographic characteristics and premorbid personality disorder traits, in order to investigate for differences in the premorbid period of the disease, in relation to age of onset and sex. Age cutoff points were set at <30 years and ≥35 years of age for young and late onset groups, respectively. The Structured Clinical Interview for DSM-IV-Patient Edition for Axis I disorders (SCID-P) was used prospectively for diagnoses. Premorbid personality disorder traits were retrospectively assessed by using the Structured Clinical Interview for DSM-IV-Patient Edition for Axis II disorders (SCID-II). Comparisons were performed by applying the two-tailed Wilcoxon rank-sum and the χ(2) statistical tests. Young onset patients were characterized by significantly higher proportion of urban birth, single status, more avoidant premorbid personality disorder traits, and less passive-aggressive premorbid personality disorder traits, than late onset counterparts. Differences were more prominently shown in men. Earlier age of onset seems to be associated to increased social inhibition and worse psychosocial adaptation in the premorbid period of paranoid schizophrenia.

A latent profile analysis of schizotypy, temperament and character in a nonclinical population: association with neurocognition

Schizotypy is conceptualized as a latent personality construct that confers liability for schizophrenia, while it is also suggested that schizotypy can relate to certain favorable aspects. Investigating individual-level interactions between schizotypy and broader personality characteristics might give a clue to this question. We aimed to identify homogeneous classes of individuals based on schizotypy, temperament and character and to validate this classification using comprehensive neurocognitive data. We studied 455 nonclinical adults using the Schizotypal Personality Questionnaire, the Temperament and Character Inventory, and an array of neuropsychological tests. A latent profile analysis (LPA) of schizotypy, temperament and character was conducted, and cognitive performance was compared as a function of latent class membership. LPA provided a 3-class solution. Of the sample, 15% was classified into a "high-positive-schizotypy/adaptive" group characterized by high cognitive-perceptual but low interpersonal schizotypy, together with low harm avoidance and high self-directedness, cooperativeness and self-transcendence; 18% was classified into a "high-schizotypy/maladaptive" group characterized by overall high schizotypy, together with high harm avoidance and low self-directedness and cooperativeness; and 67% was classified into a "low-schizotypy/adaptive" group characterized by overall low schizotypy, together with intermediate-to-low harm avoidance, high self-directedness and intermediate-to-high cooperativeness. Overall cognitive performance of the high-positive-schizotypy/adaptive group was comparable to that of the low-schizotypy/adaptive group and superior to that of the high-schizotypy/maladaptive group. The present LPA clearly defines a group of individuals who have adaptive personality traits and intact neuropsychological functions despite high positive schizotypy, suggesting that there may be complex, nonlinear relationships between schizotypal traits and psychopathology.

A positive relationship between harm avoidance and brain nicotinic acetylcholine receptor availability

Prior research indicates that disturbance of cholinergic neurotransmission reduces anxiety, leading to the hypothesis that people with heightened cholinergic function have a greater tendency toward anxiety-like and/or harm-avoidant behavior. We sought to determine if people with elevated levels of harm avoidance (HA), a dimension of temperament from the Temperament and Character Inventory (TCI), have high α4β2* nicotinic acetylcholine receptor (nAChR) availability. Healthy adults (n=105; 47 non-smokers and 58 smokers) underwent bolus-plus-continuous infusion positron emission tomography (PET) scanning using the radiotracer 2-[18F]fluoro-3-(2(S)azetidinylmethoxy) pyridine (abbreviated as 2-FA). During the uptake period of 2-FA, participants completed the TCI. The central study analysis revealed a significant association between total HA and mean nAChR availability, with higher total HA scores being linked with greater nAChR availability. In examining HA subscales, both 'Fear of Uncertainty' and 'Fatigability' were significant, based on higher levels of these characteristics being associated with greater nAChR availabilities. This study adds to a growing body of knowledge concerning the biological basis of personality and may prove useful in understanding the pathophysiology of psychiatric disorders (such as anxiety disorders) that have similar characteristics to HA. Study findings may indicate that heightened cholinergic neurotransmission is associated with increased anxiety-like traits.

Temperament and character in individuals at ultra-high risk for psychosis and with first-episode schizophrenia: associations with psychopathology, psychosocial functioning, and aspects of psychological health

OBJECTIVE

The psychobiological model of temperament and character indicates that personality traits are heritable and, during development, constantly influence one's susceptibility to schizophrenia. Our objective was to evaluate temperament and character in subjects at ultra-high risk (UHR) for psychosis and individuals with first-episode schizophrenia.

METHODS

UHR for psychosis subjects (n = 50), first-episode schizophrenia patients (n = 33), and normal controls (n = 120) were compared on temperament and character dimensions, and correlation analysis of each personality dimension with psychopathologies, global and social functioning, and self-esteem. General and social self-efficacy reports were conducted. UHR subjects were followed-up for 24 months and the baseline personality dimensions were compared between the converted and non-converted groups.

RESULTS

Both clinical groups showed abnormal personality traits in terms of temperament (higher harm avoidance, lower reward dependence and persistence) and character (lower self-directedness and cooperativeness). Psychosocial functioning and psychological health components were found to be correlated with some personality dimensions. The conversion rate of overt psychotic disorder was 25.0% at the 24-month follow-up. Baseline cooperativeness dimension was a significant predictive dimension for conversion into overt psychosis in the UHR group during the follow-up period.

CONCLUSION

Patients with first episode schizophrenia have a pervasively altered personality profile from normal controls. More importantly, this altered personality profile already emerged in putative prodromal, UHR individuals. The present findings indicate that certain personality traits can play a protective or vulnerable role in developing schizophrenia.

A relationship between hallucination proneness and character and temperament: a mediating role of meta-cognitive beliefs in a non-clinical sample

We investigated a mediating role of meta-cognitions in the relationship between Cloninger's temperament and character dimensions and hallucination proneness among healthy subjects (n=135). Two character dimensions-self-directedness and self-transcendence-were related to hallucination proneness. Negative beliefs about uncontrollability of thoughts partially mediated the relationship between these two character dimensions and hallucination proneness.

Increase in harm avoidance by genetic loading of schizophrenia

BACKGROUND

Schizophrenia is highly familial neuropsychiatric disorder with heritability estimated at 60% to 90%. Even unaffected first-degree relatives of schizophrenia manifested some neuropsychologic abnormalities, neurologic soft sign, and morphologic anomalies. Because personality traits are under genetic influence and considerable heritability, we intended to evaluate temperament and character of first-degree relatives of schizophrenia and the influence of schizophrenia genetic loading on their temperament and character.

METHODS

Temperament and Character Inventory was completed by 97 first-degree relatives of schizophrenia or schizoaffective disorder, 48 schizophrenic probands (44 patients with schizophrenia and 4 patients with schizoaffective disorder), and 106 control subjects. Within first-degree relatives, parents who have additional probands with schizophrenia spectrum disorder in their ascendant or collateral pedigree and siblings who have offspring with schizophrenia spectrum disorder were defined as presumed carriers (n = 20). Group differences in Temperament and Character Inventory scores were compared using a mixed-model analysis of variance with family as a random effect and age as a covariate.

RESULTS

Harm avoidance (HA) scores increased in the order of control subjects, the first-degree relatives, and probands. Among the relatives, presumed carriers, but not presumed noncarriers, had higher HA compared with control subjects. In addition, probands showed significantly low reward dependence, low self-directedness, and low cooperativeness scores compared with the first-degree relatives and control subjects. Probands had also higher self-transcendence scores than the first-degree relatives and had lower persistence scores than control subjects.

CONCLUSIONS

Our findings that HA increases in proportion to the genetic loading of schizophrenia suggest that it may be a potential endophenotype of schizophrenia.

A promoter variant in the chitinase 3-like 1 gene is associated with serum YKL-40 level and personality trait

The chitinase 3-like 1 (CHI3L1) gene, a cellular survival factor against several environmental and psychosocial stresses, has been sown to be more highly expressed in the hippocampus and prefrontal cortex of patients with schizophrenia than unaffected individuals. We recently reported a significant association between schizophrenia and SNP rs4950928, which is located in the promoter region of the CHI3L1 gene, in a Japanese population. The G-allele at this SNP in the gene has been associated with higher transcriptional activity in a luciferase reporter assay and with higher mRNA levels in the peripheral blood cells of patients with schizophrenia. We investigated the impact of the CHI3L1 polymorphism rs4950928 on serum YKL-40 levels, the protein product of CHI3L1. We found that individuals with the G-allele, who were more prevalent among patients with schizophrenia, had significantly higher serum YKL-40 levels (p=0.043). Personality traits are considered to be an important aspect of schizophrenia primarily because they may influence symptoms and social functioning. Personality trait analyses using the temperament and character inventory (TCI) indicated that schizophrenic patients have a unique personality profile that appears to be present across cultures. We hypothesized that higher serum YKL-40 levels are associated with personality trait in patients with schizophrenia. Thus, we next examined the impact of the risk CHI3L1 polymorphism on personality traits using the TCI. We found that individuals with the G-allele had significantly higher self-transcendence scores (p=0.0054). These findings suggest possible associations between the SNP in the CHI3L1 gene, the risk for schizophrenia, and higher serum YKL-40 levels and personality traits in a Japanese population.

Relationships between season of birth, schizotypy, temperament, character and neurocognition in a non-clinical population

While schizophrenia has been associated with a slight excess of winter/early spring birth, it is unclear whether there is such an association in relation to schizotypal personality traits. Season of birth has also been reported to relate to temperament and character personality dimensions and cognitive functioning. Moreover, non-clinical schizotypy has been shown to be associated with mild cognitive impairment, although its precise nature is yet to be elucidated. Here we examined the relationships between season of birth, schizotypal traits, temperament and character, and cognitive function. Four hundred and fifty-one healthy adults completed the Schizotypal Personality Questionnaire (SPQ). The Temperament and Character Inventory (TCI) and a neuropsychological test battery consisting of full versions of the Wechsler Memory Scale-Revised and the Wechsler Adult Intelligence Scale-Revised, and the Wisconsin Card Sorting Test, were also administered to most of the participants. The total SPQ score of those born in winter was significantly higher than that of the remaining participants. Season of birth was not significantly associated with any of the TCI dimensions or cognitive test results. Significant but mild relationships between higher SPQ scores and lower scores on some aspects of IQ were observed. These results support the notion that schizotypy and schizophrenia are neurodevelopmental conditions on the same continuum.

Schizotypal personality in healthy adults is related to blunted cortisol responses to the combined dexamethasone/ corticotropin-releasing hormone test

BACKGROUND/AIMS

Schizotypy is viewed as a dimensional trait ranging from healthy people to schizophrenic spectrum patients. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, and accumulated evidence suggests that schizophrenia is associated with altered HPA axis function; however, HPA axis function in relation to schizotypal personality has not been well documented.

METHODS

We examined the relationship between schizotypal traits as assessed with the Schizotypal Personality Questionnaire (SPQ) and cortisol responses to the combined dexamethasone/corticotropin- releasing hormone test in 141 healthy volunteers. Subjects were divided into three groups based on their cortisol responses to the dexamethasone/corticotropin-releasing hormone test: incomplete suppressors, moderate suppressors, and enhanced suppressors. SPQ scores were compared between these three groups using the analysis of covariance, controlling for age and sex.

RESULTS

The analysis of covariance showed significant main effects of the suppressor status on the ideas of reference and suspiciousness/paranoid ideation subscales and cognitive-perceptual factor. Post-hoc analyses with Bonferroni correction revealed that the enhanced suppressors scored significantly higher than the moderate suppressors on these SPQ indices.

CONCLUSION

These results indicate that nonclinical schizotypal traits in healthy adults are associated with blunted cortisol reactivity, potentially suggesting a shared neuroendocrinological mechanism across schizophrenia spectrum pathology.

Temperament, character, and quality of life in patients with schizophrenia and their first-degree relatives

The aim of this study was to investigate the associations between the temperament, character dimensions, and quality of life (QOL) of patients with schizophrenia; their first-degree, nonaffected relatives; and healthy control subjects. One hundred twenty patients, the same number of first-degree relatives, and the same number of control subjects were assessed using the Temperament and Character Inventory and the Quality of Life Enjoyment and Satisfaction Questionnaire. Patients were also assessed using the Positive and Negative Syndrome Scale. Patients and relatives had a significantly lower QOL than control subjects, controlled for temperament and character dimensions. Patients scored significantly higher than control subjects in harm avoidance and self-transcendence and lower in novelty seeking and self-directedness. First-degree relatives had lower results for novelty seeking and scored higher on self-transcendence than control subjects. Harm avoidance, self-directedness, and self-transcendence were the dimensions of Temperament and Character Inventory shown to be the most significant predictors of QOL. Psychopathology and age were also significant predictors of QOL. Our understanding of an individual patient's QOL must include personality evaluation.

Relationship between prepulse inhibition of acoustic startle response and schizotypy in healthy Japanese subjects

Prepulse inhibition (PPI) of the acoustic startle reflex (ASR) is the most common psychophysiological index of sensorimotor gating. Several studies have investigated the relationship of PPI of ASR to schizotypy in Caucasians. However, little has been reported on this relationship in Asians. We investigated a possible relationship between PPI of ASR and schizotypy in 79 healthy Japanese subjects. Schizotypy was assessed by the Schizotypal personality Questionnaire (SPQ). PPI was evaluated at signal-to-noise ratios (SnRs: difference between background noise intensity and prepulse intensity) of +12, +16, and +20 dB. The total SPQ score, cognitive/perceptual score, and interpersonal score correlated negatively with PPI at SnR of +16 and +20 dB. We conclude that PPI is associated with the trait of schizotypy in healthy Asian subjects.

Effect of age and gender on schizotypal personality traits in the normal population

AIM

There is some evidence that age and gender influence expression of schizotypal traits in the normal population. One important limitation of previous studies, however, is the restricted age range of subjects. The aim of the present study was therefore to investigate the effect of gender and age on schizotypal personality features.

METHODS

A total of 1024 participants aged between 16 and 90 were assessed using the schizotypal personality questionnaire. The effect of gender and age on schizotypal features was investigated. Confirmatory factor analysis was used to examine the factor structure of the scale in different age groups.

RESULTS

Male subjects scored higher than women in negative and disorganized-like symptoms. Female subjects scored significantly in social anxiety and odd belief subscales. Younger participants significantly scored higher in reference, odd belief, unusual perceptual experiences, odd behavior and odd speech subscales. While decreases in schizotypy scores were gradual for most of the scales, increased disorganization in female subjects was restricted to late adolescence. Confirmatory factor analysis of the data supported modified versions of the Raine three-factor model across all age groups.

CONCLUSION

Psychological changes related to adolescence and better social adaptation as a result of life experience might contribute to the age- and gender-related differences in schizotypy.

Psychopathology and personality traits in psychotic patients and their first-degree relatives

Personality dimensions have been associated with symptoms dimensions in schizophrenic patients (SP). In this paper we study the relationships between symptoms of functional psychoses and personality dimensions in SP and their first-degree relatives (SR), in other psychotic patients (PP) and their first-degree relatives (PR), and in healthy controls in order to evaluate the possible clinical dimensionality of these disorders. Twenty-nine SP, 29 SR, 18 PP, 18 PR and 188 controls were assessed using the temperament and character inventory (TCI-R). Current symptoms were evaluated with positive and negative syndrome scale (PANSS) using the five-factor model described previously (positive [PF], negative [NF], disorganized [DF], excitement [EF] and anxiety/depression [ADF]). Our TCI-R results showed that patients had different personality dimensions from the control group, but in relatives, these scores were not different from controls. With regard to symptomatology, we highlight the relations observed between harm avoidance (HA) and PANSS NF, and between self-transcendence (ST) and PANSS PF. From a personality traits-genetic factors point of view, schizophrenia and other psychosis may be initially differentiated by temperamental traits such as HA. The so-called characterial traits like ST would be associated with the appearance of psychotic symptoms.

Temperament and character dimensions in patients with schizophrenia, relatives, and controls

Studies of patients with schizophrenia or schizophrenia spectrum disorders and general population control groups consistently show differences regarding personality dimensions. However, the profile of personality dimensions in first-degree relatives of those patients is not well understood. We used Temperament and Character Inventory to explore personality dimensions in 61 clinically stable patients with schizophrenia or schizophrenia spectrum disorders, 59 of their first-degree relatives, and 64 healthy controls. Patients scored significantly higher than controls in harm avoidance and self-transcendence and lower in self-directedness and cooperativeness. First-degree relatives showed a tendency to lower novelty seeking and self-transcendence than controls. Interpretations of these findings include the possibility that lower novelty seeking and lower self-transcendence provide a protective influence in the relatives. Further studies are needed to go into this issue in greater depth.

Affective traits in schizophrenia and schizotypy

This article reviews empirical studies of affective traits in individuals with schizophrenia spectrum disorders, population-based investigations of vulnerability to psychosis, and genetic and psychometric high-risk samples. The review focuses on studies that use self-report trait questionnaires to assess Negative Affectivity (NA) and Positive Affectivity (PA), which are conceptualized in contemporary models of personality as broad, temperamentally-based dispositions to experience corresponding emotional states. Individuals with schizophrenia report a pattern of stably elevated NA and low PA throughout the illness course. Among affected individuals, these traits are associated with variability in several clinically important features, including functional outcome, quality of life, and stress reactivity. Furthermore, evidence that elevated NA and low PA (particularly the facet of anhedonia) predict the development of psychosis and are detectable in high-risk samples suggests that these traits play a role in vulnerability to schizophrenia, though they are implicated in other forms of psychopathology as well. Results are discussed in terms of their implications for treatment, etiological models, and future research to advance the study of affective traits in schizophrenia and schizotypy.

Temperament and character as schizophrenia-related endophenotypes in non-psychotic siblings

BACKGROUND

Quantitative endophenotypes are needed to better understand the pathogenesis of schizophrenia. The psychobiological model of temperament and character suggests that personality traits are heritable and regulated by brain systems influencing schizophrenia susceptibility. Thus, measures of temperament and character may serve as schizophrenia-related endophenotypes in individuals with schizophrenia and their non-psychotic siblings.

METHODS

Individuals with schizophrenia (n=35), their non-psychotic siblings (n=34), controls (n=63), and their siblings (n=56) participated in a study of the clinical, neurocognitive and neuromorphological characteristics of schizophrenia. A mixed-model approach assessed group differences on the Temperament and Character Inventory (TCI). Neurocognitive deficits and psychopathology were correlated with the TCI. Configurations of TCI domains were examined using a generalized linear model.

RESULTS

Individuals with schizophrenia and their non-psychotic siblings had higher harm avoidance than controls and their siblings. Individuals with schizophrenia had lower self-directedness and cooperativeness, and higher self-transcendence than their non-psychotic siblings, controls, and the siblings of controls. Neurocognition was not related to temperament and character in individuals with schizophrenia or either control group. In non-psychotic siblings, self-directedness and cooperativeness were correlated with working memory and crystallized IQ.

CONCLUSION

Evidence supports harm avoidance as a schizophrenia-related endophenotype. An increased risk of schizophrenia may be associated with asociality (configured as high harm avoidance and low reward dependence), schizotypy (configured as low self-directedness, low cooperativeness, and high self-transcendence), and neurocognitive deficits (poor executive functioning, working/episodic memory, attention, and low IQ). The non-psychotic siblings demonstrated features of a mature character profile including strong crystallized IQ, which may confer protection against psychopathology.