Personality traits in chronic pain patients related to endorphin levels in cerebrospinal fluid

Interindividual differences in endorphin levels may relate to widespread changes in adaptive processes, and endorphin levels may thus be related to personality traits. In 40 patients with chronic pain syndromes of both psychogenic and organic origin, endorphin levels in cerebrospinal fluid (CSF) were determined, and the patients completed Eysenck's Personality Inventory (EPI) and the Cesarek Marke Personality Scheme. Twenty-seven of the patients also completed the Zuckerman Sensation Seeking Scale (SSS). As a comparison group 30 healthy volunteers completed the personality inventories. The chronic pain patients were characterized by guilt feelings, need for order, low need for autonomy, and low tendency toward sensation seeking. Low levels of endorphins in CSF were found in patients with high scores on all the subscales in the SSS and low scores on the neuroticism subscale in the EPI.     

Markers for vulnerability to psychopathology: temperament traits associated with platelet MAO activity

The functional linkage between platelet MAO activity and psychopathology was explored by analyzing temperamental correlates in 40 male subjects by means of scales from the Eysenck Personality Questionnaire (EPQ), the Zuckerman Sensation Seeking Inventory, and the Karolinska Scales of Personality (KSP). Linear correlations were found with two sensation seeking scales, replicating earlier findings. However, nonlinear correlations predominated. Subjects with intermediate platelet MAO activity had higher scores in conformity scales and lower scores in anxiety and hostility scales than low and high MAO subgroups. Low MAO subjects showed a pattern of higher scores in KSP Impulsiveness, EPQ Neuroticism, and KSP Somatic Anxiety and Irritability and lower scores in KSP Socialization, in line with personality profiles found in alcoholics, psychopaths, and suicide attempters who also tend to have low platelet MAO activity. High MAO subjects scored lower in sensation seeking and conformity scales and higher in KSP Psychasthenia, Muscular Tension and Suspicion scales, consistent with clinical links between high platelet MAO activity and anxiety and paranoia.     

Personality correlates of platelet monoamine oxidase (MAO) activity in female and male subjects

Associations between platelet monoamine oxidase (MAO) activity and scale scores from the Eysenck Personality Questionnaire, the Impulsiveness-Venturesomeness-Empathy inventory and the Karolinska Scales of Personality were studied in 32 female and 29 male students (age range 17-19 years). There were significant negative correlations between MAO activity and extraversion-related scales for male subjects; in the female group the correlations were also negative but nonsignificant. When comparing subgroups with low, intermediate, and high platelet MAO activity subjects, consistent trends were observed in the direction of higher scores in the impulsivity scales, the sensation seeking-related Monotony avoidance scale, and the Indirect Aggression scale for both female and male low MAO activity groups.     

Bipolar sensation seeking is associated with a propensity to abuse rather than to temperamental characteristics.

OBJECTIVE: As some temperament profiles may be markers of genetic vulnerability traits, we aimed to compare sensation seeking in euthymic bipolar patients and in controls. METHODS: One hundred ninety-four patients fulfilling DSM-IV diagnostic criteria for bipolar disorders (BP), 81% of whom presented type I BP, and 95 controls were included in this study. Euthymia was assessed using both the MADRS and Bech mania scales. Subjects were evaluated using the French abbreviated form of Zuckerman's Sensation Seeking Scale (SSS), which provide a total score (TS) and four subscores: Thrill and Adventure Seeking (TAS), Experience Seeking (ES), Disinhibition (Dis), and Boredom Susceptibility (BS). RESULTS: SSS total score differed significantly between men (17.2 +/- 0.5) and women (15.3 +/- 0.6) (P = 0.02) and all the subscores were negatively correlated with age. On adjustment for sex and age, we found that bipolar patients had a high Dis score (P = 0.003). However, if the same analysis was performed with a lifetime history of alcohol abuse or dependence as a covariable, no such difference was found (P = 0.436). The SSS demonstrated a high degree of test-retest reliability (ICC = 0.91). CONCLUSION: These results suggest that sensation seeking assessed with the SSS is not a temperament characteristic associated with bipolar disorders but is instead linked to a tendency towards alcohol abuse.     

Platelet monoamine oxidase activity in sensation seekers

Personality traits, as assessed by personality inventories, and platelet monoamine oxidase activities have been compared in the following two groups of normal subjects: (1) subjects who either have mountaineering as an active hobby or an interest in mountaineering and (2) subjects not interested in mountaineering. The group of subjects interested in mountaineering were found to be sensation seekers, as assessed by the Zuckerman Sensation Seeking Scale, and to have significantly lower platelet monoamine oxidase activities.     

Low platelet monoamine oxidase and sensation seeking in males: an established relationship?

A significant negative correlation between platelet monoamine oxidase (MAO) activity, a stable peripheral enzyme measure under genetic control, and sensation seeking, as measured using the Zuckerman Sensation Seeking Scale (SSS), has been reported for male subjects in several studies. As tobacco smoking has been related to both these measures, in the present study correlations were calculated among smoking and non-smoking male university students. Platelet MAO activity was negatively correlated with the Disinhibition and Total scales of the SSS. These correlations were not significantly different in smokers and non-smokers. The results are discussed in terms of recent evidence of reduced platelet MAO activity in psychiatric patients.     

Personality traits and platelet monoamine oxidase activity in a Swedish male criminal population

BACKGROUND: A Swedish male criminal population was grouped into personality disorder subgroups and investigated with regard to personality traits and platelet monoamine oxidase (MAO) activity. The main aim of the study was to examine the possibility of a risk factor combination by having low platelet MAO activity as well as belonging to a certain diagnostic DSM-IV axis I (drug abuse in the present series) and/or II subgroup. METHODS: Personality disorders were grouped into clusters according to the cluster system used in DSM-IV axis II. The prisoners were grouped into five subgroups and each subject completed the Karolinska Scales of Personality self-report questionnaire. The comparison group for the personality data comprised 51 non-criminal males from a longitudinal Swedish project. Platelet MAO activity was assessed for the criminals as well as for a control group including 60 non-criminal healthy male Caucasians. For testing the existence of syndromes, a configuration frequency analysis (CFA) was used. RESULTS: The results showed low scores on the socialisation and high scores on the sensation seeking-related traits impulsiveness and monotony avoidance, and the somatic anxiety-related muscular tension in the criminals with any DSM-IV mental disorder, however most markedly in cluster AB and cluster B subjects. In addition, cluster AB subjects had significantly lower platelet MAO activity than controls. Two significant 'types' were found among the criminals: one was characterised by low platelet MAO activity, cluster B personality diagnosis as well as drug abuse disorder diagnosis; and the other by a pattern of normal platelet MAO activity, no cluster B personality disorder and no drug abuse disorder diagnosis. CONCLUSION: The aggregation of certain risk factors in the same individual has been shown to contribute to the development of criminal behaviour.     

Neurotransmitter systems and personality measurements: a study in psychosomatic patients and healthy subjects

A comparative study performed in psychosomatic patients (PG) and healthy subjects (HG) reveals several correlations between personality measurements (Minnesota Multiphasic Personality Inventory, Sensation Seeking Scale, Susceptibility to Punishment), and biochemical variables (in serum: MHPG, acetylcholinesterase, calcium, melatonin; and in platelets: monoamine oxidase B, serotonin, calcium proteins). The relationship between some Sensation Seeking subscales and the enzymatic activities evaluated (negative with MAO and positive with AChase) and the opposite sign relationship between serotonin and some scales of MMPI in both groups studied (negative in the PG and positive in the HG) are noteworthy.     

Psychopathology and comorbidity of psychiatric disorders in patients with kleptomania

OBJECTIVE: This study compared patients with kleptomania, patients with alcohol abuse or dependence, and psychiatric patients without impulse-control disorders or substance-related disorders on several key psychopathological dimensions. In addition, the comorbidity of kleptomania with other psychiatric disorders was examined. METHOD: Eleven patients with kleptomania recruited over a cumulative 2-year period and 60 patients with alcohol abuse or dependence and 29 psychiatric comparison patients recruited over a consecutive 6-month period participated in structured clinical interviews to determine the presence of impulse-control and substance-related disorders and of other psychiatric disorders that were comorbid with kleptomania. Psychopathological dimensions were measured with the Barratt Impulsiveness Scale, the Sensation Seeking Scale, the Montgomery-Asberg Depression Rating Scale, and the anxiety and depression subscales of the Hospital Anxiety and Depression Scale. RESULTS: Significant group effects were found for the Barratt Impulsiveness Scale total and cognitive impulsivity scores, with the patients with kleptomania having higher impulsivity scores than the other groups. Significant group differences were found on the Sensation Seeking Scale total and disinhibition scores. No significant group effects were found for the mood and anxiety measures. Patients with kleptomania had high rates of comorbid psychiatric disorders, particularly mood disorders, other impulse-control disorders, and substance abuse or dependence (mainly nicotine dependence). CONCLUSIONS: Kleptomania presented a specific psychopathological profile that distinguished patients with this disorder from patients with alcohol abuse or dependence and other psychiatric comparison patients. Impulsivity was the major psychopathological feature of kleptomania. A link between kleptomania and affective disorder was supported by the high rate of comorbid affective disorders in patients with kleptomania and a specific pattern of variation in the two conditions over time. Further prospective studies are needed to confirm this pattern. Because kleptomania is characterized by a low rate of comorbid substance-related disorders other than nicotine dependence and by severe psychopathology, it could be an appropriate disorder in which to study the information processes and psychobiology underlying impulsivity.     

Mental and personality disorders as well as personality traits in a Swedish male criminal population

The study describes personality traits and the presence of personality disorders and mental disorders in a consecutive series of 130 male prisoners in Swedish jails sentenced for serious criminality. The investigation included a psychiatric examination by means of the Structured Clinical Interview (SCID) as well as information taken from criminal records. Personality assessments were made by means of self-report questionnaires, the Karolinska Scales of Personality (KSP) and the DSM-IV and ICD-10 Personality Disorder Questionnaire (DIP-Q). The most common mental disorders were alcohol and drug abuse/dependence, which were present in 55% of the subjects. Personality disorders, too, were common, being present in 56% of the subjects. In the KSP, high scores were found in scales related to impulsiveness, sensation-seeking, nervous tension and distress, cognitive-social anxiety, hostility and aggression. Very low scores were found in the Socialization scale, reflecting a high degree of psychopathy-related personality traits. Despite the high morbidity, the global level of functioning was unexpectedly high, 66 according to GAF. The male prisoners sentenced for heavy criminality had a high degree of both mental disorders and personality disorders. Furthermore, psychopathy-related personality traits were common.     

Changes in some personality traits after recovery from alcohol dependence/abuse, anxiety and depression--results of a 5-year follow-up in a general population sample of women

The aim of this study was to analyse stability of and change in personality traits in a general population sample of women over 5 years. Specific questions were how personality traits changed after a first episode of alcohol dependence/abuse (ADA), anxiety or depression disorders and after remission of an episode. The study was based on data from a longitudinal general population-based survey titled, "Women and alcohol in G?teborg (WAG)". A total of 641 women were interviewed in 1990 or 1995 and re-interviewed after 5 years. Personality traits were assessed with the Karolinska Scales of Personality (KSP) and lifetime psychiatric diagnoses given according to the Diagnostic and Statistical Manual of Mental Disorders, 3rd revised edition (DSM-III-R). Mean T-scores (KSP) for the general population sample were stable between initial assessment and follow-up 5 years later. Correlations between assessments were high for most KSP scores, indicating high individual stability. For women with resolved ADA, KSP scores were normalized to five scales at the follow-up assessment: somatic anxiety, muscular tension, monotony avoidance, social desirability and irritability. Women who recovered from anxiety disorders during the follow-up had decreased scores in somatic anxiety and muscular tension and increased scores in verbal aggression. Women who developed ADA during follow-up had increased scores on the scales impulsiveness and verbal aggression. Women who developed depression during follow-up had increased monotony avoidance. Personality traits were generally stable in this adult female population but some personality traits changed in association with changes in psychiatric disorders. This knowledge could be useful in evaluation of treatment needs and treatment outcome.     

Exteroceptive suppression of temporalis muscle activity in subjects with high and low aggression traits.

STUDY AIM: There is evidence that the second exteroceptive suppression period of temporalis muscle activity (ES2) is modulated by the 5-HT neuronal activity in the brainstem, and the aggression trait is also connected with the cerebral 5-HT neuronal innervation. We therefore studied the temporalis ES2 in subjects with high and low aggression traits. METHODS: Sixty-five subjects with either low or high aggression trends, judged by clinical interview, answered the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ), the Zuckerman Sensation Seeking Scales (SSS) and the Plutchik-van Praag Depression Inventory (PVP). These also underwent a temporalis ES2 test procedure. Twenty-two subjects with a high ZKPQ aggression trait score and 27 with a low score were selected for data analysis. RESULTS: On average, the high aggression group displayed significantly reduced temporalis ES2 duration, elevated ZKPQ Impulsive Sensation Seeking, Neuroticism-Anxiety and Aggression-Hostility, and PVP scores. The personality traits were not related with either latency or duration of temporalis ES2 in any group. The PVP score, however, was negatively correlated with ES2 duration in all 49 subjects. CONCLUSIONS: This study demonstrates neurophysiologic signs of brainstem dysfunction in subjects with high aggression traits.     

Relationships between attempted suicide, temperamental vulnerability, and violent criminality in a Swedish forensic psychiatric population.

The relationship between suicide attempts and different vulnerability factors was investigated in 61 male subjects during forensic psychiatric examination. Personality traits and psychopathy were determined by means of the Karolinska Scales of Personality (KSP) and the Psychopathy Checklist-Revised (PCL-R). Clinical diagnoses were determined by the use of Structured Clinical Interview for DSM-III-R (SCID). Platelet monoamine oxidase (MAO) activity was investigated in 58 subjects.Suicide attempters had extremely low socialization and high impulsive aggression. This was independent of a history of repeatedly criminal violence or not. They had higher PCL-R scores and lower levels of platelet MAO activity than non-attempters. No relationship was found between suicide attempts and repeated violent criminality. However, among the subjects with repeated criminal violence there was a highly significant difference between suicide attempters and non-attempters, indicating different personality profiles in violent offenders with and without suicidal behavior. Suicidal behavior was significantly associated with borderline personality disorder, but not with any other single DSM-III-R disorder. The results show a far more severe personality disturbance in suicide attempters than in other violent patients in this type of population. Suicidal behavior should therefore be evaluated and treated per se.     

Paranoia and platelet MAO in normals and nonschizophrenic psychiatric groups.

The authors compared the correlation between platelet monoamine oxidase (MAO) activity and the Paranoia (Pa) scale of the Minnesota Multiphasic Personality Inventory in several groups. The data suggest that there is a positive association between high MAO activity and high scores on the Pa scale but only in samples with psychopathology.     

Which temperamental characteristics are associated with substance use in subjects with psychotic and mood disorders?

The aim of this study was to assess the associations between substance use disorders and temperamental characteristics in subjects with non-affective psychotic disorders or mood disorders. Consecutively hospitalized patients were interviewed with a structured diagnostic interview to define DSM-IV diagnoses, including those of substance use. Temperamental characteristics were measured using the Sensation-Seeking Scale (SSS), the Barratt Impulsivity Scale (BIS) and the Physical Anhedonia Scale. Inpatients (n=103) with non-affective psychotic disorders (n=45) or mood disorders (n=58) were included. Among these patients, 25.2% presented with a lifetime (LT) history of alcohol abuse/dependence and 23.3% presented with a LT history of cannabis abuse/dependence. A LT history of alcohol misuse was independently associated with higher scores at the 'experience seeking' and 'disinhibition' subscales of the SSS. A LT history of cannabis misuse was independently associated with higher scores on the 'disinhibition' subscale of the SSS and on the 'non-planning activity' subscale of the BIS. These results suggest that sensation-seeking and impulsivity are temperamental characteristics that may favor substance use in patients with psychotic or mood disorders, independently from categorical diagnoses.     

Elevated platelet MAO is related to impulsivity in disruptive behavior disorders

Platelet monoamine oxidase (MAO) activity was measured in 32 drug-free prepubertal boys with externalizing symptoms of disruptive behavior disorders and 47 boys with no DSM-III-R diagnoses, and correlated to questionnaire and laboratory performance measures of impulsivity. A subgroup of boys with high MAO activity exhibited significantly poorer performance (i.e., more impulsivity) than a subgroup of low MAO activity on laboratory tasks requiring response inhibition. High MAO patients were more impulsive than high MAO controls on some performance tasks and elevated platelet MAO was unrelated to personality questionnaire measures of impulsivity or to patient status. These data suggest that biological markers such as MAO activity may correlate better with performance than clinical questionnaire measures. Abnormally high platelet MAO activity may not be sufficient to produce externalizing symptoms in children, perhaps interacting with an underlying behavioral dimension of impulsivity.     

Platelet MAO and measures of attention and impulsivity in boys with attention deficit disorder and hyperactivity

Platelet monoamine oxidase (MAO) activity was studied in 22 boys diagnosed as having attention deficit disorder with hyperactivity and 12 healthy control boys admitted to a clinical research center and placed on a diet low in monoamines. The hyperactive boys had lower platelet MAO activity than controls, and MAO activity was related to performance on the Matching Familiar Figures Test (MFF) and the Continuous Performance Test (CPT), which yield scores sensitive to impulsivity and inattention. Furthermore, it was negatively related, in hyperactive boys only, to two tests of reading and spelling achievement. Administration of d-amphetamine and placebo in a double-blind crossover design did not significantly raise MAO levels above baseline and was minimally related to improved performance on the MFF and CPT.     

Sensation seeking and psychopathology

A sample of 2,115 persons responded to an article in a popular magazine by taking the Sensation Seeking Scale (SSS) and supplying personal information by mail, including data about past treatment, hospitalization, and diagnosis of psychiatric disorders. Subjects falling into certain diagnostic categories were closely matched with controls from the same sample who reported no history, treatment, or diagnosis of disorder. SSS scores were not related to general psychopathology, unipolar depression, schizophrenia, or neurosis, but were found to be elevated in persons reporting a history of manic-depressive or sociopathic spectrum (including alcoholism and drug abuse) disorder.     

Thyroid hormones and personality traits in attempted suicide

The research on thyroid hormones and personality traits is quite sparse and mainly focused on male forensic psychiatric populations in which the relationship between thyroid hormones and psychopathy and aggression-related personality traits has been reported. The suicidal temperament hypothesis suggests that certain personality traits such as aggression, anxiety proneness, impulsivity, and low socialization may render an individual vulnerable to the risk of suicide. The aim of this study was to investigate personality traits assessed by the Karolinska Scales of Personality (KSP) in relation to hormones in the hypothalamic–pituitary–thyroid (HPT) axis in 100 euthyroid suicide attempters. Standard multiple regression analyses were performed with TSH, T3, T4, and the T3/T4 ratio, respectively, as the dependent variable and KSP factors (Anxiety Proneness, Aggressiveness, and Impulsivity) and subscales (Detachment, Social Desirability, and Socialization) as independent variables. In men, but not in women, the regression model of the T3/T4 ratio was significant and the results suggested that high scores on Aggressiveness and low ones on Detachment were associated with a low T3/T4 ratio. These results indicate that HPT function may be related to Aggressiveness and Detachment in male suicide attempters.     

Psychological traits and platelet monoamine oxidase activity in eating disorder patients: their relationship and stability

Self-reported behavior and attitudes towards eating [Eating Disorder Inventory-2; Garner DM (1991). Eating Disorder Inventory-2: Professional Manual. Odessa, Fl.: Psychological Assessment Resources; Estonian version Podar I, Hannus A, Allik J (1999). Personality and Affectivity Characteristics Associated With Eating Disorders: a Comparison of Eating Disordered, Weight-Preoccupied, and Normal Samples. J Pers Assess; 73(1), 133-147] and the activity of platelet monoamine oxidase (MAO) was studied in 11 patients with anorexia nervosa (AN), 43 patients with bulimia nervosa (BN) and a healthy control group (n=138). Nineteen patients filled in the EDI-2 questionnaire and donated blood samples three times with three month intervals in order to determine platelet MAO activity. Eating disordered (ED) patients scored higher on all EDI-2 subscales and had lower MAO activity compared to the control group. They also scored higher than the control group on the Neuroticism domain but lower on the Extraversion, Openness, and Conscientiousness domains of the NEO-PI-R questionnaire. The average stability of MAO on different occasions (r=.56) was slightly smaller than the stability of the EDI-2 scores (r=.70). The lack of correlations between personality dispositions and MAO activity indicates that they have independent influence on eating disorders. A possible relationship between neurochemical mechanisms and psychological symptoms of eating disordered behavior is discussed.