The contribution of temperament and character to schizotypy multidimensionality

Schizotypy could be viewed either as an underlying "personality organization" that includes the "liability" to schizophrenia, i.e., as a hypothetical latent construct, or it could be referred to the phenotypic manifestations of a particular personality organization. The psychobiologic model of the structure of personality accounts for dimensions of both temperament and character. This study examined the covariances between Temperament and Character Inventory (TCI) scores and aspects of Schizotypal Personality Questionnaire (SPQ) scores in a nonclinical sample. The results showed the relationship between the number of schizotypal phenotypic traits, as quantified by SPQ measures, and a specific configuration of character, namely, high self-transcendence (ST), low self-directedness (SD), and low cooperativeness (C). Data suggested that the unique combination of high ST, low SD, and low C seems to lead to a special risk for schizotypy. In particular, ST is a predictor either of psychosis proneness or mature, effective adapted and self-satisfied personalities, depending on its interaction with other TCI dimensions, both temperament and character.     

Relationships between headache and sleep in a non-clinical population of children and adolescents

BACKGROUND: Headache and sleep are related in different ways and alterations of chronobiological mechanisms are involved in headache. We investigated the relationships between headache and sleep quality in a large non-clinical population of children and adolescents and evaluated the relationship between headache and circadian typologies. METHODS: A total of 1073 children and adolescents (50.9% males; mean age=10.56; range=8-15 years) were recruited from four schools in Rome. They filled out the questionnaires individually in classrooms, after brief group instruction about answer formats. The questionnaires included (a) a self-report headache questionnaire to collect information on different aspects of headache attacks based on the International Classification of Headache Disorders-2nd edition (ICHD-2); (b) the School Sleep Habits Survey that incorporated questions about sleep habits, the Sleep-Wake Problems Behaviour Scale (SWPBS), the Sleepiness Scale (SLS) and the Morningness/Eveningness Questionnaire (MEQ). RESULTS: According to ICHD-2 criteria, we classified 70 (6.5%) children as Migraine Group (MG), 135 (12.7%) as Non-Migraine Headache Group (NMG), and the remaining 868 (80.8%) were classified as Headache-Free Group (HFG). No clear differences have been found between MG and NMG regarding the frequency of the attacks, although MG showed a significantly increased frequency of long-lasting attacks. The modality of onset of pain and the location of pain was similar in both groups. The most frequent triggering factor for headache in MG and NMG was "a bad sleep" (32.2%) followed by emotional distress (27.8%). No differences have been found between MG, NMG and HFG in sleep schedule or sleep duration. MG and NMG showed significantly higher scores on the SWPBS vs. HFG, while MG presented higher scores on the SLS compared to NMG and HFG. MG presented lower MEQ scores, indicating a more pronounced eveningness. CONCLUSIONS: The relationships between headache and sleep problems are evident even in a non-clinical population of children and adolescents, with MG showing poorer sleep quality, sleepiness and a tendency toward eveningness.     

Associations between cognitive biases and domains of schizotypy in a non-clinical sample

Schizotypy is a non-clinical manifestation of the same underlying biological factors that give rise to psychotic disorders (Claridge and Beech, 1995). Research on normative populations scoring high on schizotypy is valuable because it may help elucidate the predisposition to schizophrenia (Jahshan and Sergi, 2007) and because performance is not confounded by issues present in schizophrenia samples. In the current study, a Confirmatory Factor Analysis was conducted using several comprehensive measures of schizotypy. As expected and replicating prior research, a four-factor model of schizotypy emerged including a positive, a negative, a cognitive disorganization, and an impulsive nonconformity factor. We also evaluated how each factor related to distinct cognitive biases. In support of hypotheses, increased self-certainty, decreased theory of mind, and decreased source memory were associated with higher scores on the positive factor; decreased theory of mind was associated with higher scores on the negative factor; and increased self-certainty was associated with greater impulsive nonconformity. Unexpectedly, decreased self-certainty and increased theory of mind were associated with greater cognitive disorganization, and decreased source memory was associated with greater impulsive nonconformity. These findings offer new insights by highlighting cognitive biases that may be risk factors for psychosis.     

Season of birth variations in the temperament and character inventory of personality in a general population.

BACKGROUND: Since several studies show season of birth variations in morbidity, suicidal behavior and CSF (cerebrospinal fluid) monoamine metabolites, we investigated season of birth variations in personality in the population. METHODS: We analyzed by multiple logistic regressions the Temperament and Character Inventory (TCI) for 2,130 individuals taking part in the Betula prospective random cohort study of Ume?, Sweden. RESULTS: The personality dimensions were correlated significantly with age and gender. We stratified the data according to age, gender and the season of TCI measurement. By the median split in each stratum, a high-value group and a low-value group were obtained for each of the personality dimensions. Those born during February to April were significantly more likely than those born during October to January to have high NS (novelty seeking) among women, particularly the subscale NS2 (impulsiveness vs. reflection), and to have high PS (persistence) among men. Temperament profiles also showed season of birth variations. CONCLUSIONS: We discuss the associations in the literature between personality and the monoamines serotonin and dopamine, and suggest that our results are compatible with a hypothesis of season of birth variation in the monoamine turnover. The personality traits are likely to be influenced by several genetic and environmental factors, one of them being the season of birth.     

Theory of mind, neurocognition, and functional status in schizotypy

The present study is the first to concurrently examine social cognition, neurocognition, and social functioning in psychometric schizotypes. Screening of 2108 undergraduates with the Schizotypal Personality Questionnaire-Brief (SPQ-B) identified 52 persons high in schizotypy and 40 persons low in schizotypy. All participants were administered a test battery designed to assess two elements of neurocognition, verbal secondary memory (California Verbal Learning Test) and executive functioning (Wisconsin Card Sorting Test), two elements of social cognition, emotion perception (The Awareness of Social Inference Test-Part 1) and theory of mind (The Awareness of Social Inference Test-Parts 2 and 3), and social functioning (Social Adjustment Scale-Self Report). Although the persons with high schizotypy were impaired in social functioning relative to the persons with low schizotypy, they were not impaired in theory of mind, emotion perception, verbal secondary memory, or executive functioning. Theory of mind and verbal secondary memory were correlated in persons with high schizotypy. The present findings suggest that psychometric schizotypes are not impaired in the domains of social cognition and neurocognition examined.     

Moderating effect of schizotypy on the relationship between smoking and neurocognition

PurposeSmoking rates in schizotypic individuals are shown to be elevated, as in patients with schizophrenia, although findings on the association of smoking with different symptomatology of schizotypy have been mixed. Moreover, possible moderating effects of schizotypy on the relationship between smoking and cognition have not been well documented.Subjects and methodsThe Schizotypal Personality Questionnaire (SPQ) and the full version of the Wechsler Memory Scale-Revised (WMS-R) were administered to 501 healthy adults. Subjects were divided into smokers (n = 85) and non-smokers (n = 416) based on the presence/absence of current smoking.ResultsThe analysis of covariance (ANCOVA) on the three factor scores as well as the total score of the SPQ, controlling for age and gender, revealed that cognitive-perceptual factor was significantly associated with an increased rate of smoking (P = 0.048). The ANCOVA on the WMS-R indices, with smoking group as a fixed factor and age, gender and total SPQ score as covariates, revealed that the schizotypy-by-smoking interaction was significant for attention/working memory (P = 0.029).Discussion and conclusionPositive schizotypy may be associated with more smoking. Schizotypy and smoking could interact with each other to negatively affect attention/working memory.     

Relationships between schizotypy and subjective experiences in a sample of 399 university students

The high-risk approach based on the definition of schizotypy by Meehl (The American Psychologist 1962;17:827-38) and the basic symptom approach proposed by Huber (Fortschritte für Neurologie und Psychiatrie 1957;25:491-520) share many points in common. In particular, several studies have shown that high scores on psychosis proneness or subjective experiences (SE) scales were associated with the onset of psychotic disorders in nonpsychiatric or nonpsychotic subjects. However, the relationships between the 2 concepts have never been studied experimentally. The present study was therefore designed to investigate the relationships between the scores of the SE scale and several psychosis proneness scales evaluating the negative and positive components of schizotypy in a sample of 399 university students. Data were analyzed using multiple regression and principal components analyses. The results show that SE, as assessed by the Frankfurt Complaint Questionnaire, were significantly associated with the positive component of schizotypy but not with the negative component. Subjective experiences could constitute vulnerability traits for psychosis and the Frankfurt Complaint Questionnaire could be use instead of the positive psychosis proneness scales.     

Interrelations between temperament, character, and parental rearing among delinquent adolescents: a cross-validation

We performed a cross-validation of results from investigations in juvenile delinquents in Russia and Germany concerning relationships of personality characteristics in terms of temperament and character with parental rearing. Both studies used the Temperament and Character Inventory (TCI) based on Cloninger's psychobiological theory, and the Own Memories on Parenting (Egna Minnen Betr?ffande Uppfostran-Swedish [EMBU]) questionnaire on parental rearing based on Perris' vulnerability model. The inter-relatedness of parental rearing, temperament, and character traits in socially normally integrated adolescents, as well as in delinquent adolescents, implying direct and indirect pathways from personality and parental rearing to delinquency, could be cross-validated. Differences between delinquents and socially normally integrated adolescents are rather based on different levels of expressions of various temperament traits, harm avoidance and novelty seeking in particular, and the character trait self-directedness, as well as on parental rearing behavior (predominantly parental rejection and emotional warmth) than on different structures within related developmental processes.     

Relationship between serotonin and the temperament and character inventory

We explored relationships between positive symptoms of schizophrenia and neurocognitive functions (language and memory). The semantic and phonemic associations among words produced in a verbal fluency task by 26 participants diagnosed with DSM-III-R schizophrenia were examined. Formal thought disorder was associated with producing fewer contextually related words and with producing more unrelated words. In contrast, hallucinations were associated with producing more related words. Our results suggest associations between formal thought disorder and impaired memory, and between hallucinations and increased lexical activation/excessive synaptic pruning.     

Association between attachment prototypes and schizotypy dimensions in two independent non-clinical samples of Spanish and American young adults

Attachment theory offers a powerful theoretical framework for elucidating the developmental pathway through which childhood interpersonal trauma confers vulnerability to psychosis. In the present study, the association between attachment and schizotypy was explored in two independent non-clinical samples of Spanish (n=547) and American (n=1425) young adults. Participants completed the Relationship Questionnaire and the Wisconsin Schizotypy Scales. Following attachment theory and cognitive accounts of psychosis, it was hypothesized that preoccupied attachment would be associated with positive schizotypy, dismissing attachment with negative schizotypy, and fearful attachment with both schizotypy dimensions. Results confirmed these predictions, thus supporting the theoretical frameworks invoked. Also, the associations found in these non-clinical samples are consistent with those in clinical psychosis, supporting the continuum model of schizotypy and schizophrenia. Finally, there was cross-cultural consistency of these associations. Overall, the findings support the application of attachment theory for furthering our understanding of whether different insecure styles, characterized by different self and other representations and affect regulation strategies, play a role in the pathways to positive and negative symptoms.     

The relationship between the biogenetic temperament and character and psychopathology in adolescents

BACKGROUND: This study was conducted to investigate the relationship between patterns of temperament and character and self-reported psychopathology in adolescents from the community. SAMPLING AND METHODS: The Junior Temperament and Character Inventory (JTCI) and Youth Self-Report (YSR) instruments were administered to 623 Korean middle school students (boys/girls = 331/292; age = 13.3 +/- 0.9 years old). Multiple linear regression analyses were used to evaluate the relationship between temperament and character based on Cloninger's biogenetic theory of personality and youth psychopathology of internalizing and externalizing problems. RESULTS: Internalizing problems of the YSR (withdrawn, somatic complaint and anxious/depressed scales) were significantly related to high Harm Avoidance and low Reward Dependence (JTCI temperament) and low Self-Directedness and high Self-Transcendence (JTCI character). Externalizing problems of the YSR (delinquency and aggression) were significantly associated with high Novelty Seeking and high Harm Avoidance (JTCI temperament) and low Self-Directedness, low Cooperativeness and high Self-Transcendence (JTCI character). CONCLUSIONS: Findings of the current study suggest that specific patterns of temperament and character potentially influence adolescents' psychopathology in the community.     

Intrusive thoughts in a non-clinical adolescent population

The frequency and pattern of intrusive thoughts reported by 279 adolescent school pupils and the relation of these to self-reported anxiety, depression and obsessional ritualisation are examined.Similarities in the frequency and processing of intrusive thoughts were identified between this group and previously studied adult populations. Self-reported symptoms of anxiety, depression and obsessional ritualisation were associated with both discomfort and interference from intrusive thoughts. Factor analysis of the data produced a three-factor solution and the interpretation and implications of this result are discussed in terms of affectivity, ritualisation and superstitious or magical beliefs.     

Sociodemographic predictors of temperament and character

The Unified Biosocial Theory of Personality postulates that human personality is organized around four temperaments - Novelty Seeking, Harm Avoidance, Reward Dependence, and Persistence - and three characters - Self-Directedness, Cooperativeness, and Self-Transcendence. The objective of the present study was to investigate the influence of sociodemographic factors on temperament and character without the confounding influence of mental disorders. Volunteers (n=94) did not meet criteria for any Axis I and Axis II diagnosis, had no first-degree relatives with mental disorders, and were medically healthy. After giving written informed consent, volunteers completed the Temperament and Character Inventory. Analyses were conducted to determine the degree of association of each sociodemographic factor (i.e., age, gender, ethnicity, marital status, educational attainment, and occupational status) to personality dimension, while controlling for possible interactions with other sociodemographic factors. Partial correlation analysis showed a significant association between gender and Reward Dependence, and occupational status was significantly related to Reward Dependence, Cooperativeness, and Self-Transcendence. Stepwise regression analysis indicated that gender and occupational status were significant predictors of Reward Dependence. Occupational status was the only predictor of Cooperativeness and Self-Transcendence. These data suggest that sociodemographic factors should be considered in studies investigating temperaments and characters as defined by the Unified Biosocial Theory of Personality.     

Relationships between temperament dimensions in personality and unconscious emotional responses.

BACKGROUND: In addition to character dimensions, personality includes temperament dimensions, defined as individual differences in implicit associative learning responses to environmental stimuli processed by unconscious memories. We examined whether temperament dimensions were associated with patterns of unconscious emotional responses of an autonomic nature. METHODS: From 70 healthy men, high and low novelty-seeking (NS) groups and high and low harm-avoidance (HA) groups were selected using scores on the Tridimensional Personality Questionnaire measuring temperament dimensions. Emotionally negative, neutral, and positive visual stimuli were presented subliminally using backward masking, and skin conductance responses (SCRs) were measured as an autonomic index of emotional responses. Skin conductance responses to the three emotional stimulus conditions were compared between groups. RESULTS: Skin conductance responses in the high NS group were significantly greater than in the low NS group when positive or negative emotional stimuli were presented but not neutral stimuli. Skin conductance responses in the high HA group were significantly greater than in the low HA group for stimuli of all three valences. CONCLUSIONS: Autonomic response patterns to unconscious emotional perception differed between NS and HA, suggesting that different dimensions of temperament may be associated with different patterns of unconscious emotional responses. Novelty seeking and HA may be associated with specificity and susceptibility of preattentive emotional perception, respectively.     

Basic symptoms, temperament and character in adolescent psychiatric disorders

Objective: Basic symptoms are early subtle changes in thinking, feeling and perception that are subjectively experienced and precede the onset of a psychotic illness. In adult samples, high basic symptom scores are regarded as specific risk factors for the development of schizophrenia. The aim of this study was to explore the relevance of basic symptoms of psychiatric disorders in adolescent patients with special focus on early detection of psychosis. Furthermore, the association between basic symptoms and personality traits has been investigated. METHOD: From 89 adolescents, who were consecutive inpatients with different psychiatric disorders in 1995 and 1997, 54 were followed up 4.7 years later. Patients were examined with the Bonn Scale for the Assessment of Basic Symptoms at the time of the first presentation and follow-up. Additionally, personality traits were assessed at follow-up using the Junior Temperament and Character Inventory. RESULTS: None of the subjects made the transition to schizophrenia, despite high baseline scores of basic symptoms at the initial assessment. Indirect minus symptoms were found to be the most valid predictor of a persisting psychiatric diagnosis. In addition, this specific category was strongly associated with the personality traits harm avoidance and self-directedness. CONCLUSION: In adolescents, basic symptoms in association with personality traits present as a nonspecific indicator of psychopathology rather than as an indicator of vulnerability to schizophrenia.     

Relationships between self-reported potentially traumatizing events, psychoform and somatoform dissociation, and absorption, in two non-clinical populations

OBJECTIVE: Some authors have suggested that the personality characteristic 'fantasy proneness' may mediate the correlation between reported potentially traumatizing events and dissociative symptoms. Other authors question the reported magnitude of this correlation in non-clinical samples, because these are usually derived from student samples and may therefore suffer from a restriction of range. The primary aim of this study is to assess the relationship between a self-report measure of traumatization and psychoform dissociation as well as somatoform dissociation in a non-clinical population, while accounting for the influence of fantasy proneness. METHOD: Two random non-clinical samples, that is, a student and an adult non-student sample, completed a range of relevant self-report questionnaires. Absorption was used as an index of fantasy proneness. RESULTS: The range of reported potentially traumatizing events was restricted in students, compared to non-students. In both samples a significant correlation was found between reported potentially traumatizing events and dissociation. After partialling out absorption, the relationship between reported potential traumatization and psychoform dissociation diminished substantially in both samples. The magnitude of the correlation with somatoform dissociation decreased to a lesser degree, so that it remained significant in both samples. CONCLUSIONS: The correlation between somatoform dissociation and reported traumatization, after partialling out absorption, gives a reliable estimate of the magnitude of the relationships between potentially traumatizing events and dissociation. Findings regarding traumatization and dissociation in students should be generalized to the general population cautiously.     

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

BackgroundConsiderable 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.MethodThe 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.ResultsConsistent 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.ConclusionsAssociations 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.     

Properties of the temperament and character inventory in a Chinese sample

OBJECTIVE: To determine the influence of language and culture on the temperament and character (TCI) measure in a Chinese sample. METHOD: We translated the TCI into Mandarin and had a non-psychiatric sample of Malaysian Chinese subjects complete the TCI at baseline and at a 1-month retest, with subsets completing English or Mandarin versions alternatively or on both occasions. Analyses examine the TCI factor structure and any impact of language and culture on TCI scoring. RESULTS: We identified age, gender, occupation and language effects on TCI scale scores. Test-retest reliability was high and not compromised by language. Scale internal consistency was also high. Factor analyses of separate sets of TCI scales corresponded strongly to the structure identified in the TCI development studies. CONCLUSION: The results indicate that TCI is likely to have applicability to Chinese subjects, and argue against properties being constrained by the English language or by western culture.