Personality differences in schizophrenia are related to performance on neuropsychological tasks

Psychiatric symptoms and response quality to self-rated personality tests: Evidence from the PsyCoLaus study

Despite the fact that research has demonstrated consistent associations between self-rated measures of personality dimensions and mental disorders, little has been undertaken to investigate the relation between psychiatric symptoms and response patterns to self-rated tests. The aim of this study was to investigate the association between psychiatric symptoms and response quality using indices from our functional method. A sample of 1,784 participants from a Swiss population-based cohort completed a personality inventory (NEO-FFI) and a symptom checklist of 90 items (SCL-90-R). Different indices of response quality were calculated based on the responses given to the NEO-FFI. Associations among the responses to indices of response quality, sociodemographic characteristics and the SCL-90-R dimensions were then established. Psychiatric symptoms were associated with several important differences in response quality, questioning subjects' ability to provide valid information using self-rated instruments. As suggested by authors, psychiatric symptoms seem associated with differences in personality scores. Nonetheless, our study shows that symptoms are also related to differences in terms of response patterns as sources of differences in personality scores. This could constitute a bias for clinical assessment. Future studies could still determine whether certain subpopulations of subjects are more unable to provide valid information to self-rated questionnaires than others.

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.

Phase-locking index and power of 40-Hz auditory steady-state response are not related to major personality trait dimensions

Although a number of studies have demonstrated state-related dependence of auditory steady-state responses (ASSRs), the investigations assessing trait-related ASSR changes are limited. Five consistently identified major trait dimensions, also referred to as "big five" (Neuroticism, Extraversion, Openness, Agreeableness and Conscientiousness), are considered to account for virtually all personality variances in both healthy people and those with psychiatric disorders. The purpose of the present study was, for the first time, to establish the link between 40-Hz ASSR and "big five" major personality trait dimensions in young healthy adults. Ninety-four young healthy volunteers participated (38 males and 56 females; mean age ± SD 22.180 ± 2.75). The 40-Hz click trains were presented for each subject 30 times with an inter-train interval of 1-1.5 s. The EEG responses were recorded from F3, Fz, F4, C3, Cz, C4, P3, Pz and P4 locations according to 10/20 electrode placement system. Phase-locking index (PLI) and event-related power perturbation (ERSP) were calculated, each providing the following characteristics: peak time, entrainment frequency, peak value and mean value. For assessing "big five" personality traits, NEO Personality Inventory Revised (NEO-PI-R) was used. No significant correlation between 40-Hz ASSR PLI or ERSP and "big five" personality traits was observed. Our results indicate that there is no dependence between 40-Hz ASSR entrainment and personality traits, demonstrating low individual 40-Hz variability in this domain. Our results support further development of 40-Hz ASSR as a neurophysiological marker allowing distinguishing between healthy population and patients with psychiatric disorders.

Conscientiousness increases efficiency of multicomponent behavior

Many everyday situations require the flexible interruption and changing of different actions to achieve a goal. Several strategies can be applied to do so, but those requiring high levels of cognitive control seem to confer an efficiency (speed) advantage in situations requiring multi-component behavior. However, it is elusive in how far personality traits affect performance in such situations. Given that top-down control is an important aspect of personality and furthermore correlates with conscientiousness, N = 163 participants completed the NEO-FFI and performed an experimental (stop-change) paradigm assessing multicomponent behavior. Applying mathematical constraints to the behavioral data, we estimated the processing strategy of each individual. The results show that multicomponent behavior is selectively affected by conscientiousness which explained approximately 19% of the measured inter-individual behavioral variance. Conscientiousness should hence be seen as a major personality dimension modulating multicomponent behavior. Highly conscientious people showed a more effective, step-by-step processing strategy of different actions necessary to achieve a goal. In situations with simultaneous requirements, this strategy equipped them with an efficiency (speed) advantage towards individuals with lower conscientiousness. In sum, the results show that strategies and the efficiency with which people cope with situations requiring multicomponent behavior are strongly influenced by their personality.

Cognitive task performance and symptoms contribute to personality abnormalities in first hospitalized schizophrenia

Chronic schizophrenia patients have personality abnormalities and cognitive deficits that are associated with poor clinical, social, and vocational outcomes. Very few studies have examined relationships between personality and cognitive function, and chronic illness effects may have confounded those studies. In this study personality traits in clinically stable first episode schizophrenia patients (21M, 9F) and psychiatrically healthy controls (38M, 24F) were measured with the NEO-FFI, a self-report measure of neuroticism, extraversion, openness, agreeableness, and conscientiousness. All subjects completed the Information, Digit Span, Vocabulary, and Digit Symbol subtests of the Wechsler Adult Intelligence Scale; and Trails A and B. Standard statistical techniques were used to quantify relationships between personality and symptom levels and/or task performance, and relative contributions of diagnosis and task performance to personality variance. Patients showed elevated mean neuroticism and openness, and reduced mean extraversion, agreeableness and conscientiousness. Task performance and negative symptoms contributed significantly and uniquely to most personality dimensions in patients. Task performance accounted for significant amounts of personality variance even after accounting for diagnosis, and it also contributed to personality variance in controls. These results suggest that cognitive deficits and negative symptoms contribute to consistently observed personality abnormalities in this disorder, and that the contribution of neuropsychological performance to personality variance may be independent of diagnostic classification. Personality abnormalities in schizophrenia may stem from the neurocognitive deficits associated with this disorder, and add to their adverse effects on social and vocational functioning.

Social alienation in schizophrenia patients: association with insula responsiveness to facial expressions of disgust

INTRODUCTION

Among the functional neuroimaging studies on emotional face processing in schizophrenia, few have used paradigms with facial expressions of disgust. In this study, we investigated whether schizophrenia patients show less insula activation to macro-expressions (overt, clearly visible expressions) and micro-expressions (covert, very brief expressions) of disgust than healthy controls. Furthermore, departing from the assumption that disgust faces signal social rejection, we examined whether perceptual sensitivity to disgust is related to social alienation in patients and controls. We hypothesized that high insula responsiveness to facial disgust predicts social alienation.

METHODS

We used functional magnetic resonance imaging to measure insula activation in 36 schizophrenia patients and 40 healthy controls. During scanning, subjects passively viewed covert and overt presentations of disgust and neutral faces. To measure social alienation, a social loneliness scale and an agreeableness scale were administered.

RESULTS

Schizophrenia patients exhibited reduced insula activation in response to covert facial expressions of disgust. With respect to macro-expressions of disgust, no between-group differences emerged. In patients, insula responsiveness to covert faces of disgust was positively correlated with social loneliness. Furthermore, patients' insula responsiveness to covert and overt faces of disgust was negatively correlated with agreeableness. In controls, insula responsiveness to covert expressions of disgust correlated negatively with agreeableness.

DISCUSSION

Schizophrenia patients show reduced insula responsiveness to micro-expressions but not macro-expressions of disgust compared to healthy controls. In patients, low agreeableness was associated with stronger insula response to micro- and macro-expressions of disgust. Patients with a strong tendency to feel uncomfortable with social interactions appear to be characterized by a high sensitivity for facial expression signaling social rejection. Given the associations of insula responsiveness to covert disgust expression with low agreeableness in healthy individuals, insula responsiveness to expressions of disgust might be in general a neural marker of the personality trait of agreeableness.

A controlled study of personality and affect in Tourette syndrome

OBJECTIVE

Tourette syndrome (TS) can increase the likelihood of social and emotional difficulties which may shape an individual's personality and self-perception. We investigated personality and affect in patients with TS.

METHODS

Twenty-five adults with TS (2 with co-morbid obsessive compulsive disorder, 4 with co-morbid attention-deficit hyperactivity disorder and 4 with both co-morbidities), who were not clinically depressed, and 25 matched controls participated in the study. They completed the Ten-Item Personality Index, the Positive and Negative Affect Scale and the Beck Depression Inventory.

RESULTS

Adults with TS exhibited no differences from controls in reported emotional experience or depressive symptoms but did differ for four of the five assessed personality dimensions; extraversion, conscientiousness, openness and emotional stability. Individuals with pure TS (who had no co-morbid conditions) exhibited reduced extraversion and emotional stability compared to controls. Personality scores were not related to tic severity, yet lower emotional stability scores were associated with higher ratings of negative affect.

CONCLUSIONS

This study is limited by a restricted sample in terms of size and source. However, our findings indicate that in the absence of depression and common co-morbidities, people with TS differ from controls in indices of personality, which are linked to negative affectivity.

BDNF serum concentrations in first psychotic episode drug-naïve schizophrenic patients: associations with personality and BDNF Val66Met polymorphism

AIMS

To investigate the relationship among brain derived neurotrophic factor (BDNF) serum concentrations, BDNF Val66Met polymorphism and personality profile in drug-naïve schizophrenic patients with first-episode psychosis (FEP) and healthy participants.

MAIN METHODS

This cross-sectional study included fifty FEP patients and fifty healthy participants who served as controls. To study their personality profile the standardized Greek version of the Alternative Five-Factor Zuckerman-Kuhlman Personality Questionnaire (ZKPQ) was administered. Serum BDNF levels were measured and genotyping of BDNF Val66Met polymorphism was performed in patients and healthy subjects.

KEY FINDINGS

FEP patients presented lower BDNF serum concentrations (P=0.002) and higher scores in ZKPQ Neuroticism (P=0.001) and Aggression-Hostility (P=0.002) scales while lower scores in the ZKPQ Sociability scale (P<0.001) than healthy participants. Multivariate analysis revealed that the odds of being assessed with FEP were 0.4 times lower in those with higher BDNF values (P<0.001) and 1.8 times greater in those with higher Neuroticism scores (P<0.001). There were no significant differences with respect to the Val66Met polymorphism between patients and healthy participants.

SIGNIFICANCE

Reduced BDNF serum concentrations along with higher Neuroticism scores might be associated with FEP. A complex interplay between BDNF serum concentrations, personality traits, BDNF Val66Met polymorphism, and psychotic symptomatology has been arisen but further investigation is needed to better clarify the observed associations.

A short-term, comprehensive, yoga-based lifestyle intervention is efficacious in reducing anxiety, improving subjective well-being and personality

Objective:

To assess the efficacy of a short-term comprehensive yoga-based lifestyle intervention in reducing anxiety, improving subjective well-being and personality.

Materials and Methods:

The study is a part of an ongoing larger study at a tertiary care hospital. Participants (n=90) included patients with chronic diseases attending a 10-day, yoga-based lifestyle intervention program for prevention and management of chronic diseases, and healthy controls (n=45) not attending any such intervention.

Primary Outcome Measures:

Change in state and trait anxiety questionnaire (STAI-Y; 40 items), subjective well-being inventory (SUBI; 40 items), and neuroticism extraversion openness to experience five factor personality inventory revised (NEO-FF PI-R; 60 items) at the end of intervention.

Results:

Following intervention, the STAI-Y scores reduced significantly (P<0.001) at Day 10 (66.7 ± 13.0) versus Day 1 (72.5 ± 14.7). Also, positive SUBI scores (F1– F6) improved significantly (P<0.01) at Day 10 versus Day 1. Similarly NEO-FF PI-R scores improved significantly (P<0.001) at Day 10 versus Day 1. Control group showed an increase in STAI-Y while SUBI and NEO-FF PI-R scores remained comparable at Day 10 versus Day 1.

Conclusions:

The observations suggest that a short-term, yoga-based lifestyle intervention may significantly reduce anxiety and improve subjective well-being and personality in patients with chronic diseases.

Perceived parental attachment, personality characteristics, and cognition in male incest

The aim of this study was to investigate the multiple pathways of perceived child-rearing practices, cognitive-executive functions, and personality characteristics in incest and other sexual offenders. The participants consisted of 217 male sexual offenders who were in custody in southern Taiwan. Participants were divided into two groups of 25 incest and 192 nonincest sexual offenders. The incest offenders tended to be less extraverted and worse in abstract reasoning ability, and to have more perseverative thinking, and perceived less parental care than other sexual offenders. Moreover, the structural equation model showed that the effect of parental care on the type of sexual offense is mediated by cognitive-executive functions and personality traits. This finding suggests that the personality traits, cognitive function, and parental attachment of incest offenders differ from other sexual offenders. This result can be a helpful reference in sexual-offender intervention programs for relapse prevention.

Neurophysiological impairment in emotional face processing is associated with low extraversion in schizophrenia

Patients with schizophrenia have low extraversion and high neuroticism. These personality traits affect the everyday life of patients with schizophrenia, making it important to investigate neurobiological basis of personality traits. In healthy people, extraversion is associated with hemodynamic responses in the amygdala and electrophysiological brain activity such as event-related potential and event-related desynchronization during emotional face processing. Patients with schizophrenia show abnormal neural activity during emotional face processing, such as an N170 amplitude reduction. However, few studies to date have reported an association between personality traits and neural activity during emotional face processing in schizophrenia. In the present study, we examined N170 during emotional face processing, and association with personality traits in patients with schizophrenia. Fifteen male patients with chronic schizophrenia and 15 healthy male subjects participated in this study. Patients with schizophrenia had reduced N170 amplitudes (p=0.007). While healthy subjects had increased N170 amplitudes in response to emotional faces compared with neutral faces (p=0.003), patients with schizophrenia showed no difference in N170 amplitudes between emotional and neutral faces (p=0.60). Reduced N170 amplitude in response to neutral faces was correlated with low extraversion scores in patients with schizophrenia (r(s)=-0.69, p=0.005). The abnormal N170 and its association with extraversion in schizophrenia were found at the right rather than the left posterior temporal electrode. An abnormal N170 in schizophrenia may reflect impairments in the structural encoding of emotional faces, and indiscrimination between emotional and neutral faces at this stage of information processing. The association between abnormal N170 amplitudes and extraversion suggests that abnormal neural activity in the early stages of emotional face processing may underlie low extraversion characteristic of schizophrenia.

Pergolide treatment of cognitive deficits associated with schizotypal personality disorder: continued evidence of the importance of the dopamine system in the schizophrenia spectrum

Cognitive deficits observed in schizophrenia are also frequently found in individuals with other schizophrenia spectrum disorders, such as schizotypal personality disorder (SPD). Dopamine appears to be a particularly important modulator of cognitive processes such as those impaired in schizophrenia spectrum disorders. In a double-blind, placebo-controlled clinical trial, we administered pergolide, a dopamine agonist targeting D(1) and D(2) receptors, to 25 participants with SPD and assessed the effect of pergolide treatment, as compared with placebo, on neuropsychological performance. We found that the pergolide group showed improvements in visual-spatial working memory, executive functioning, and verbal learning and memory. These results suggest that dopamine agonists may provide benefit for the cognitive abnormalities of schizophrenia spectrum disorders.

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.

Predicting schizophrenia patients' real-world behavior with specific neuropsychological and functional capacity measures

BACKGROUND

Significant neuropsychological (NP) and functional deficits are found in most schizophrenia patients. Previous studies have left questions as to whether global NP impairment or discrete domains affect functional outcomes, and none have addressed distinctions within and between ability and performance domains. This study examined the different predictive relationships between NP domains, functional competence, social competence, symptoms, and real-world behavior in domains of work skills, interpersonal relationships, and community activities.

METHODS

Two hundred twenty-two schizophrenic outpatients were tested with an NP battery and performance-based measures of functional and social competence and rated for positive, negative, and depressive symptoms. Case managers generated ratings of three functional disability domains.

RESULTS

Four cognitive factors were derived from factor analysis. Path analyses revealed both direct and mediated effects of NP on real-world outcomes. All NP domains predicted functional competence, but only processing speed and attention/working memory predicted social competence. Both competence measures mediated the effects of NP on community activities and work skills, but only social competence predicted interpersonal behaviors. The attention/working memory domain was directly related to work skills, executive functions had a direct effect on interpersonal behaviors, and processing speed had direct effects on all three real-world behaviors. Symptoms were directly related to outcomes, with fewer relationships with competence.

CONCLUSIONS

Differential predictors of functional competence and performance were found from discrete NP domains. Separating competence and performance provides a more precise perspective on correlates of disability. Changes in specific NP or functional skills might improve specific outcomes, rather than promoting global functional improvement.

Normal personality characteristics in schizophrenia: a review of the literature involving the FFM

Schizophrenia is generally viewed as a disruption of normal functioning because of an underlying core illness. A number of theorists have speculated that this core illness may unilaterally disrupt normal personality functioning. However, recent data suggests that the relationship may be more complex and reciprocal than previously conceptualized. Furthermore, basic personality characteristics appear to be associated with numerous clinical phenomena. This article reviews the empirical literature pertaining to normal personality characteristics [structured around the five-factor model (FFM) of personality] in individuals with schizophrenia. Evidence suggests that certain personality characteristics may be uniquely related to the etiology of psychosis, as well as symptom severity, occupational functioning, cigarette smoking, substance use and violent behavior, social isolation, and suicidality in patients with schizophrenia. The implications of these findings and suggestions for future research are discussed.