Gender differences in depression: the role of personality factors

The goal of the study was to determine the association between gender and the Big Five personality factors, and to identify the role of personality factors in the association between gender and depression among adults in the United States. Data were drawn from the Midlife Development in the United States Survey (N=3032). Multivariate analysis of variance (MANOVA) was used to examine gender differences on the Big Five personality factors (i.e. agreeableness, neuroticism, openness to experience, extraversion, and conscientiousness). Multivariate logistic regression analyses were conducted to examine the relation between gender and depression, and to test whether this association is moderated by neuroticism. Levels of neuroticism, agreeableness, extraversion, and conscientiousness were significantly higher among females than among males; in contrast, level of openness to experience was significantly higher among males. Female gender was associated with increased odds of experiencing depression. Results showed that neuroticism played a significant contributory role in the relationship between being female and major depression, though the role of gender remained statistically significant after adjustment. These data suggest that gender differences in personality factors, specifically neuroticism, may play a key role in the well-documented gender difference in depression. Our findings indicate that neuroticism may moderate the association between female gender and increased risk of depression among adults. These findings require replication using longitudinal data.     

Personality and non-suicidal deliberate self-harm: Trait differences among a non-clinical population

Limited information is available on understanding why particular individuals engage in non-suicidal deliberate self-harm (DSH), especially among non-clinical populations. An array of personality traits, such as those included in the five-factor model of personality, may further an understanding of DSH. The purpose of this study was to examine personality traits among non-clinical groups with or without a history of DSH. College students (N = 238) completed self-report measures of DSH and personality. Both multivariate (MANOVA, discriminant analysis) and univariate (ANOVA) statistical procedures supported the hypothesis that those with a history of DSH (n = 59) had significantly higher levels of neuroticism and openness to experience, and significantly lower levels of agreeableness and conscientiousness. Contrary to expectations, there were no differences in extraversion between the two groups. These results indicate personality differences among those with a history of DSH, which with additional research, may prove to be risk factors or targets of intervention for future DSH or collateral problems.     

Clinical, cognitive, and social characteristics of a sample of neuroleptic-naive persons with schizotypal personality disorder

INTRODUCTION: Schizotypal personality disorder (SPD) shares with schizophrenia many biological features, yet little is known about the clinical characteristics of persons diagnosed with this disorder. This report describes the clinical, cognitive and socio-occupational characteristics of a community sample of subjects diagnosed with SPD. METHOD: Sixty-four male and 40 female neuroleptic-naive DSM-IV SPD subjects and 59 male and 51 female comparison subjects were recruited from the community for a total sample of 214 subjects. Demographic and cognitive differences between groups and, within the SPD group, the effect of gender on clinical features, such as the SPD criteria, SAPS, SANS, Schizotypal Personality Questionnaire, and co-morbidity, were examined using ANOVA and Chi-square distributions. RESULTS: SPD subjects, in contrast to comparison subjects, had significantly lower socio-economic status, poorer social relationships and skills, and lower vocabulary scores. Furthermore, SPD subjects demonstrated more impairment on Vocabulary scores than on Block Design, as measured by the WAIS-R, a pattern not seen in comparison subjects. In the SPD cohort, positive symptoms predominated and nearly half were co-morbid for major depression. With respect to gender, male SPD subjects, compared with female SPD subjects, evinced significantly more negative symptoms, fewer friends, had more odd speech, and were more likely to also suffer from paranoid and narcissistic personality disorders. In contrast to male SPD subjects, female SPD subjects perceived themselves to be more disorganized. CONCLUSIONS: SPD subjects, similar to schizophrenics, are impaired socially, occupationally, and cognitively, particularly in the area of verbal measures. Moreover, male SPD subjects may be more severely affected than female SPD subjects across multiple domains of functioning.     

Personality traits in schizophrenia and related personality disorders

We investigated whether schizophrenia spectrum disorders share common personality characteristics or traits. Participants with a diagnosis of schizophrenia or schizoaffective disorder (SZ) or with a schizophrenia spectrum personality disorder (schizophrenia spectrum PD: schizoid, paranoid, and schizotypal personality disorder) were compared with non-psychiatric control subjects on the five-factor model of personality and the psychosis-proneness scales. On the five-factor personality scales, SZ subjects showed higher levels of neuroticism, and lower levels of openness, agreeableness, extraversion, and conscientiousness than control subjects. Higher scores on openness and lower scores on neuroticism distinguished schizophrenia spectrum PD from SZ. On the psychosis-proneness scales, both PD and SZ participants scored high relative to non-psychiatric control participants on magical ideation and perceptual aberration, while PD participants scored intermediate between non-psychiatric control participants and SZ on social anhedonia. Discriminant analysis indicated that schizophrenia spectrum patients could be distinguished from PDs by more severe social withdrawal and maladjustment, while subjects with PDs could be best distinguished from control subjects on the basis of odd or novel ideation and decreased conscientiousness.     

Cerebellar-dependent eyeblink conditioning deficits in schizophrenia spectrum disorders

Accumulating evidence suggests that abnormalities in neural circuitry and timing associated with the cerebellum may play a role in the pathophysiology of schizophrenia. Schizotypal personality disorder (SPD) may be genetically linked to schizophrenia, but individuals with SPD are freer from potential research confounds and may therefore offer insight into psychophysiological correlates of schizophrenia. The present study employed a delay eyeblink conditioning (EBC) procedure to examine cerebellar-dependent learning in schizophrenia, SPD, and healthy control subjects (n = 18 per group) who were matched for age and gender. The conditioned stimulus was a 400-ms tone that coterminated with a 50 ms unconditioned stimulus air puff. Cognitive performance on the Picture Completion, Digit Symbol Coding, Similarities, and Digit Span subscales of the Wechsler Adult Intelligence Scale--Third Edition was also investigated. The schizophrenia and SPD groups demonstrated robust EBC impairment relative to the control subjects; they had significantly fewer conditioned responses (CRs), as well as smaller CR amplitudes. Schizophrenia subjects showed cognitive impairment across subscales compared with SPD and control subjects; SPD subjects showed intermediate performance to schizophrenia and control subjects and performed significantly worse than controls on Picture Completion. Impaired EBC was significantly related to decreased processing speed in schizophrenia spectrum subjects. These findings support the role of altered cortico-cerebellar-thalamic-cortical circuitry in the pathophysiology of schizophrenia spectrum disorders.     

The impact of personality on symptom expression in obsessive-compulsive disorder

Previous research conducted on the five-factor model of personality (FFM) in obsessive-compulsive disorder (OCD) has demonstrated that community and clinical participants score significantly higher than controls on the domains and facets of neuroticism and extraversion and selective facets of agreeableness and conscientiousness. However, studies have yet to examine the extent to which personality traits, as assessed by the FFM, are associated with the specific symptoms of OCD. The purpose of this study was to examine further the personality predictors of obsessive-compulsive symptoms in clinical participants using the facets of the FFM. Patients with a DSM-IV diagnosis of OCD (N = 56) completed the Revised NEO Personality Inventory, the Yale Brown Obsession Compulsion Scale, and the Beck Depression Inventory. Lower scores on openness to ideas were uniquely associated with greater obsession severity, whereas lower openness to actions was uniquely associated with greater compulsive severity. In contrast with past research that has emphasized the association between neuroticism and extraversion and dimensionally rated obsessive-compulsive symptoms, this study demonstrates the specific associations between selective facet traits of openness and clinical obsessions and compulsions. Whereas tendencies toward negative affectivity may confer a nonspecific vulnerability to the development of OCD, facets of openness may impact on the particular expression and severity of obsessive-compulsive symptoms.     

Reduced anterior and posterior cingulate gray matter in borderline personality disorder.

BACKGROUND: Structural abnormalities in prefrontal and cingulate gyrus regions-important in affective processing, impulse control and cognition may contribute to the psychopathology of borderline personality disorder (BPD). Previous MRI studies examining volume have reported that compared with healthy controls, BPD patients have decreases in right anterior cingulate, no differences in dorsolateral prefrontal cortex, and mixed findings for prefrontal cortex. We extended this investigation by examining gray and white matter volume of frontal and cingulate gyrus Brodmann areas (BAs) in a large group of patients and healthy controls. METHODS: MRI scans were acquired in 50 BPD patients (n = 13 with comorbid diagnosis of BPD and Schizotypal Personality Disorder (SPD) and n = 37 without SPD) and 50 healthy controls, and gray/white matter volume in cingulate gyrus and frontal lobe BAs were assessed. Normal BPD and BPD subgroup comparisons were conducted. RESULTS: Compared with controls, BPD patients showed reduced gray matter volume in BA 24 and 31 of the cingulate. BPD patients without comorbid SPD had isolated gray matter volume loss in BA 24, but were spared for BA 31 in contrast to BPD patients with SPD. There were no group differences in whole cingulate or frontal lobe volume. CONCLUSIONS: The finding of more pervasive cingulate shrinkage in the patients with BPD and SPD comorbidity resembles recent observations with the same methods in patients with schizophrenia. The pattern of reduced anterior and posterior cingulate gray matter volume in BPD patients, particularly those comorbid for SPD is consistent with the affective and attentional deficits observed in these personality disorders.     

A longitudinal study of the relationship between personality traits and the annual rate of volume changes in regional gray matter in healthy adults

To investigate whether personality traits affect the rate of decline of gray matter volume, we analyzed the relationships between personality traits and the annual rate of changes of gray matter volume in 274 healthy community dwelling subjects with a large age range by applying a longitudinal design over 6 years, using brain magnetic resonance images (MRI) and the Revised NEO Personality Inventory (NEO‐PI‐R) at baseline. Brain MRI data were processed using voxel‐based morphometry with a custom template by applying the DARTEL diffeomorphic registration tool. For each subject, we used NEO‐PI‐R to evaluate the five major personality traits, including neuroticism, extraversion, openness, agreeableness, and conscientiousness. The results show that the annual rate of change in regional gray matter volume in the right inferior parietal lobule was correlated significantly and negatively with a personality of openness, which is known to be related to intellect, intellectual curiosity, and creativity adjusting for age, gender, and intracranial volume. This result indicates that subjects with a personality trait of less openness have an accelerated loss of gray matter volume in the right inferior parietal lobule, compared with subjects with a personality trait of more openness. Because the right inferior parietal lobule is involved in higher cognitive function such as working memory and creativity, a personality trait of openness is thought to be important for preserving gray matter volume and cognitive function of the right inferior parietal lobule in healthy adults. Hum Brain Mapp 34:3347–3353, 2013. © 2012 Wiley Periodicals, Inc.     

Personality traits in migraine and tension-type headaches: a five-factor model study

Although abnormal personality traits have been frequently reported in patients with primary headaches, the overlaps between these domains need a clear standard definition, for example, by a five-factor personality model. Moreover, personality abnormalities in patients with episodic tension-type headache (ETH) and migraine with aura (MA) are less well studied. Therefore, we administered Zuckerman-Kuhlman's Personality Questionnaire to 72 patients suffering from chronic tension-type headaches (CTH), 33 with ETH, 15 with MA and 57 with migraine without aura (MO), as well as 58 healthy subjects. Depressive trends were measured with Plutchik-van Praag's Depression Inventory. Compared to healthy controls, the CTH, ETH and MO groups showed significantly greater neuroticism-anxiety and depression. In addition, the MO group scored significantly higher on aggression-hostility than healthy controls. No abnormal personality traits were found in patients with MA. This study, from the perspective of a five-factor model, confirms most previous reports about personality in patients with primary headaches and establishes elevated aggression-hostility only in MO sufferers.     

Differential metabolic rates in prefrontal and temporal Brodmann areas in schizophrenia and schizotypal personality disorder

In an exploration of the schizophrenia spectrum, we compared cortical metabolic rates in unmedicated patients with schizophrenia and schizotypal personality disorder (SPD) with findings in age- and sex-matched normal volunteers. Coregistered magnetic resonance imaging (MRI) and positron emission tomography (PET) scans were obtained in 27 schizophrenic, 13 SPD, and 32 normal volunteers who performed a serial verbal learning test during tracer uptake. A template of Brodmann areas derived from a whole brain histological section atlas was used to analyze PET findings. Significantly lower metabolic rates were found in prefrontal areas 44-46 in schizophrenic patients than in normal volunteers. SPD patients did not differ from normal volunteers in most lateral frontal regions, but they had values intermediate between those of normal volunteers and schizophrenic patients in lateral temporal regions. SPD patients showed higher than normal metabolic rates in both medial frontal and medial temporal areas. Metabolic rates in Brodmann area 10 were distinctly higher in SPD patients than in either normal volunteers or schizophrenic patients.     

Sadistic personality disorder and comorbid mental illness in adolescent psychiatric inpatients

Sadistic personality disorder (SPD) is a controversial diagnosis proposed in the DSM-III-R, but not included in the DSM-IV. Few studies have focused on this disorder in adolescents. This article describes the results of a study that sought to determine the presence of sadistic personality characteristics in psychiatrically hospitalized adolescents and of comorbid Axis I or personality disorder patterns in those youth with SPD or SPD traits. Fifty-six adolescents were assessed for sadistic and other personality disorders with the Structured Interview for DSM-III-R Personality Disorders-Revised (SIDP-R). Axis I disorders were assessed using the Diagnostic Interview for Children and Adolescents, Adolescent Version (DICA-R-A) and portions of the Schedule for Affective Disorders and Schizophrenia for School Age Children, Epidemiologic (K-SADS-E). The youth were divided into those with SPD and SPD traits, the Sadistic Group (n = 18), and the Nonsadistic Group (n = 38). A significant proportion of the adolescents in this study met full DSM criteria for SPD (14%). The Sadistic Group (32%) had significantly more Axis I and personality pathology than did the Nonsadistic Group. However, all but one in the Sadistic Group met criteria for other personality disorders, confounding the interpretation of these findings and consistent with adult literature studies. Subjects with sadistic personality characteristics were identified in this adolescent inpatient sample, and they had more extensive Axis I and II psychopathology than the comparison group. The validity of this disorder in younger populations requires further study. Future studies should also explore the impact that the mandatory use of the pleasure/gratification criterion has on the validity of the SPD diagnosis and whether the requisite presence of this criterion decreases the overlap currently noted between SPD and other Axis II diagnoses.     

Personality in schizophrenia assessed with the Temperament and Character Inventory (TCI)

The Temperament and Character Inventory (TCI) is a well-established self-report questionnaire measuring four temperament and three character dimensions. However, surprisingly few studies have used it to examine the personality of patients with schizophrenia, and none in Japan. Moreover, possible gender differences in personality among patients with schizophrenia have not been well documented. We administered the TCI to 86 Japanese patients with schizophrenia and 115 age- and gender-matched healthy controls to characterize personality traits in patients with schizophrenia and to examine their relationships with clinical variables, particularly gender and symptoms. Compared with controls, patients demonstrated significantly lower novelty seeking, reward dependence, self-directedness and cooperativeness, and higher harm avoidance and self-transcendence. Male patients showed even more pronounced personality alteration than female patients when both of them were compared with healthy people. Personality dimensions were moderately correlated with symptom dimensions assessed by the Positive and Negative Syndrome Scale (PANSS). These results, together with prior findings in several other countries, suggest that schizophrenia patients have a unique personality profile which appears to be present across cultures and that the greater alteration of personality in schizophrenia males might be related to their poorer social and community functioning.     

Personality and social interactions in patients with acute brief psychoses

Although a particularly vulnerable personality has been postulated by some authors as a pathogenetic factor in acute and transient psychotic disorders (ATPD) as introduced with ICD-10, little empirical work has been done on the subject. We therefore evaluated personality features and social interactions in a comparative study of patients with ATPD. We recruited all consecutive inpatients fulfilling the ICD-10 criteria of ATPD (F23) during a 5-year period, as well as control groups with "positive" schizophrenia (PS) and bipolar schizoaffective disorder (BSAD) matched for gender and age at index episode. For assessment of personality features and premorbid social contacts, we administered the NEO Five-Factor Inventory and a semi-structured interview. The assessment of the "Big Five" personality dimensions (neuroticism, extraversion, openness to experience, agreeableness, conscientiousness) with the NEO-FFI did not show any significant difference between ATPD patients and healthy controls. BSAD patients differed from mentally healthy controls on 2 of 5 subscales of the NEO-FFI (neuroticism, extraversion), but were otherwise indiscernible from ATPD patients and mentally healthy controls. In contrast, PS patients showed the most pronounced differences from the mentally healthy controls on the NEO-FFI, and had significantly less premorbid social interaction than the clinical controls. Within the limits of retrospective assessment, the present findings indicate that (1) patients with ATPD do not share the premorbid social impairment characteristic of schizophrenic patients and (2) the personality of patients with ATPD does not differ substantially from the general population.     

Childhood and current autistic features in adolescents with schizotypal personality disorder

The diagnostic boundaries between autistic- and schizophrenia-spectrum disorders have varied over the years, and some overlap in diagnostic criteria persists. The present study examined childhood and current signs of autistic disorder (AD) in adolescents with schizotypal personality disorder (SPD) or other personality disorders, as well as healthy controls. A structured interview was administered to rate participants' current symptoms. Participants' guardians were interviewed with the Autism Diagnostic Inventory-Revised (ADI-R), a clinical assessment of childhood and current autistic signs. Compared to both the other personality-disordered and healthy groups, adolescents with SPD were rated as having significantly more impairment on childhood and current social functioning, and having more unusual interests and behaviors. For the entire sample, impaired childhood social functioning and unusual interests and behaviors were associated with higher negative symptom scores. Current impairments in social functioning, unusual interests and behaviors, and communication were also linked with greater negative symptoms. However, neither childhood nor current autistic features significantly predicted later conversion to an Axis I psychotic disorder over the course of three years of follow-up. The findings indicate that past and current autistic signs are more common in adolescents with SPD, but neither current nor childhood autistic features are linked with conversion to psychosis.     

Neuromotor functioning in adolescents with schizotypal personality disorder: associations with symptoms and neurocognition

Previously, Neumann and Walker (1999) used a computerized motor assessment and found that adults with schizotypal personality disorder (SPD) displayed increased and more variable motor force compared to adults with other personality disorders or healthy controls. Using the same motor assessment, the current study examined whether an independent sample of adolescents with SPD manifested a similar pattern of motor dysfunction compared to adolescents with other Axis II disorders or those without a disorder. As predicted, the SPD group showed increased and more variable force compared to the other two groups, which did not differ on these measures. These same motor variables were correlated with negative symptoms, as well as perseverative responses on a card sorting test. The significant correlations between motor functioning and perseverative responses and negative symptoms support recent research suggesting that subcortical motor regions play a role in higher order cognition and negative symptoms. Differences as well as broad similarities in the pattern of motor findings between the adult and adolescent SPD studies are discussed.     

Motor dysfunction in schizotypal personality disorder.

Past research has revealed that schizophrenia is associated with voluntary movement abnormalities, as well as higher rates of involuntary movements. On instrumental motor tasks, patients manifest reduced motor stability, excessive force and more contralateral motor overflow (movement in the non-responding hand). In the present study, an instrumental motor task (manual response forced-choice task) was administered to a group of adults with schizotypal personality disorder (SPD) in order to determine whether they show motor deficits similar to those observed in schizophrenia. As predicted, the schizotypal subjects were excessive and more variable in motor force, compared to healthy controls and other personality-disordered subjects. Additionally, the force and variability of the motor responses were positively correlated with ratings of both positive and negative SPD symptoms. Finally, motor overflow and negative symptoms were associated with higher salivary cortisol levels. The pattern of findings is consistent with previous reports linking motor abnormalities and heightened cortisol with schizotypal personality disorder.     

Gender differences in anxiety-related traits in patients with panic disorder

This study examined gender differences in anxiety-related personality traits in patients with panic disorder with or without agoraphobia (PD+/-AG). Outpatients (101 total) with SCID confirmed PD+/-AG completed the Anxiety Sensitivity Index (ASI), the Trait form of the State-Trait Anxiety Inventory (STAI-T), the NEO Personality Inventory Revised (NEO PI-R), and the Retrospective Self-Report of Inhibition (RSRI) as part of their assessment. Significant gender differences were not detected for the total ASI scores. Females scored significantly higher than males on the Physical Concerns subscale of the ASI, whereas males scored significantly higher than women on the Social Concerns subscale. Women scored higher than men on the Extraversion scale of the NEO PI-R as well as on certain subscales of this domain. Although a significant gender difference was not detected on the Neuroticism subscale, men scored higher on the angry hostility and depression facets of this trait. Significant gender differences were not found for the STAI-T or the RSRI. These findings suggest that gender differences exist among patients with PD+/-AG in the feared consequences of anxiety symptoms as well as in the personality characteristics of extraversion.     

Agreeableness and neuroticism as predictors of relapse after first-episode psychosis: a prospective follow-up study

Cross-sectional investigations, using the five-factor model of personality have evinced relationships among neuroticism, agreeableness, and psychotic symptoms. The current study examined these relationships via a prospective follow-up study with remitted first-episode psychosis patients. Baseline five-factor model personality profiles, diagnoses, symptom ratings, and premorbid adjustment ratings were followed by nine monthly ratings on Brief Psychiatric Rating Scale psychosis items in 60 first-episode patients. Valid baseline personality profiles were completed by 40 patients. Patients who had a return of symptoms scored higher on baseline neuroticism and agreeableness than those who remained in remission. Premorbid adjustment also predicted return of symptoms. After premorbid adjustment was controlled for, the agreeableness differences remained significant, but the neuroticism scores were no longer significantly different. It is concluded that lower agreeableness acts as a mediating variable in relapse. Further studies should clarify whether agreeableness is associated with specific biases in processing interpersonal information, and interpersonal behaviors.     

Beyond the mental pain: A case-control study on the contribution of schizoid personality disorder symptoms to medically serious suicide attempts

BackgroundClinical and research findings have highlighted the role of interpersonal factors in suicidal behavior with high levels of intent and lethality. Schizoid personality disorder (SPD) is at the extreme end of interpersonal difficulties. Thus, we aimed to understand the contribution of SPD symptoms to suicide behavior and specifically to more lethal suicide attempts.MethodFour groups were investigated (N = 338): medically serious suicide attempters, medically non-serious suicide attempters, psychiatric and healthy controls. SPD symptoms, mental pain variants, and clinical characteristics were assessed.ResultsOverall, attempters were characterized by higher levels of most SPD symptoms. Solitary lifestyle and emotional detachment were higher among medically serious suicide attempters relative to less-serious attempters. Emotional detachment doubled the risk for high lethality, beyond mental pain variables.ConclusionsSPD symptoms of interpersonal difficulties and low levels of emotional expressions are important risk factors for more severe suicidal behavior. Implications for identification of at-risk groups for suicide are discussed.     

Cortical gray and white matter volume in unmedicated schizotypal and schizophrenia patients

Magnetic resonance imaging (MRI) studies have revealed fronto-temporal cortical gray matter volume reductions in schizophrenia. However, to date studies have not examined whether age- and sex-matched unmedicated schizotypal personality disorder (SPD) patients share some or all of the structural brain-imaging characteristics of schizophrenia patients. We examined cortical gray/white matter volumes in a large sample of unmedicated schizophrenia-spectrum patients (n = 79 SPD, n = 57 schizophrenia) and 148 healthy controls. MRI images were reoriented to standard position parallel to the anterior–posterior commissure line, segmented into gray and white matter tissue types, and assigned to Brodmann areas (BAs) using a postmortem-histological atlas. Group differences in regional volume of gray and white matter in the BAs were examined with MANOVA. Schizophrenia patients had significantly reduced gray matter volume widely across the cortex but more marked in frontal and temporal lobes. SPD patients had reductions in the same regions but only about half that observed in schizophrenia and sparing in key regions including BA10. In schizophrenia, greater fronto-temporal volume loss was associated with greater negative symptom severity and in SPD, greater interpersonal and cognitive impairment. Overall, our findings suggest that increased prefrontal volume in BA10 and sparing of volume loss in temporal cortex (BAs 22 and 20) may be a protective factor in SPD which reduces vulnerability to psychosis.