Reward dependence is positively related to urinary monoamines in normal men

Personality and quality-of-life improvement after apomorphine infusion in Parkinson's disease

People with Parkinson's disease with motor fluctuations can be treated by continuous subcutaneous apomorphine infusion (CSAI) to reduce their symptoms. Nonetheless, factors are lacking to predict patients' quality-of-life amelioration after CSAI. This pilot study aimed to evaluate associations between personality dimensions and quality-of-life improvement after 6 months of CSAI. Thirty-nine people with Parkinson's disease awaiting CSAI were included. Linear regression models between 'Temperament and Character Inventory' personality dimensions at baseline and percentage of change in Parkinson's Disease Questionnaire-39 scores after 6 months of CSAI were realized (n = 35). The Temperament and Character Inventory was also compared between patients awaiting CSAI and patients awaiting deep brain stimulation of the sub-thalamic nucleus (n = 39 from the PREDI-STIM study). Higher reward dependence scores were associated with a better quality-of-life outcome after 6 months of CSAI, while self-directedness scores were associated with a better quality of life before CSAI (as opposed to harm avoidance, reward dependence and self-transcendence scores associated with a worse quality of life). Moreover, people with Parkinson's disease awaiting deep brain stimulation of the sub-thalamic nucleus had similar Temperament and Character Inventory dimensions compared to patients awaiting CSAI. People with Parkinson's disease with higher reward dependence scores at baseline had the best quality-of-life improvement after 6 months of CSAI. This finding could be used to better prepare and accompany people with Parkinson's disease during CSAI establishment. Moreover, this result could serve as an orientation factor to second-line treatments.

Reward Dependence-Moderated Noradrenergic and Hormonal Responses During Noncompetitive and Competitive Physical Activities

The aim of this study was to reveal whether increased reward dependence (RD) plays a role in the catecholamine neurotransmitter release and testosterone hormone regulation during physical activities among healthy trained participants. Twenty-two male participants (mean age: 40.27 ± 5.4 years) participated in this study. Two conditions were constructed, namely, a noncompetitive and a competitive running task (RT), which were separated by a 2-week interval. Urine and blood samples were collected prior to and following the running tasks. Noradrenaline (NA), adrenaline (A), dopamine (D), and their metabolites, vanillylmandelic acid (VMA) and homovanillic acid (HVA), were measured from urine, while testosterone levels were analyzed from blood samples. RD was assessed using the Cloninger's Personality Inventory (PI). Mental health was evaluated using the WHO Well-Being, Beck Depression, and Perceived Life Stress Questionnaires. According to our findings, levels of NA, A, D, VMA, and testosterone released underwent an increase following physical exertion, independently from the competitive condition of the RT, while HVA levels experienced a decrease. However, we found that testosterone levels showed a significantly lower tendency to elevate in the competitive RT, compared with the noncompetitive condition (p = 0.02). In contrast, HVA values were higher in the competitive compared with the noncompetitive condition (p = 0.031), both before and after the exercise. Considering the factor RD, in noncompetitive RT, its higher values were associated with elevated NA levels (p = 0.007); however, this correlation could not be detected during the competitive condition (p = 0.233). Among male runners, the NA and testosterone levels could be predicted to the degree of RD by analyzing competitive and noncompetitive physical exercises.

Personality dimensions of patients can change during the course of parkinson's disease

BACKGROUND

Studies assessing personality dimensions by the "Temperament and Character Inventory" (TCI) have previously found an association between Parkinson's disease (PD) and lower Novelty Seeking and higher Harm Avoidance scores. Here, we aimed to describe personality dimensions of PD patients with motor fluctuations and compare them to a normative population and other PD populations.

METHODS

All PD patients awaiting Deep Brain Stimulation (DBS) answered the TCI before neurosurgery. Their results were compared to those of historical cohorts (a French normative population, a de novo PD population, and a PD population with motor fluctuations).

RESULTS

Most personality dimensions of our 333 included PD patients with motor fluctuations who are candidates for DBS were different from those of the normative population and some were also different from those of the De Novo PD population, whereas they were similar to those of another population of PD patients with motor fluctuations.

CONCLUSIONS

During the course of PD, personality dimensions can change in parallel with the development of motor fluctuations, either due to the evolution of the disease and/or dopaminergic treatments.

Temperament and character and quality of life in lung cancer patients

Aim

The aim of this study was to test whether personality variables are independently associated with health-related quality of life (HRQOL) in lung cancer patients.

Methods

In a cross-sectional study, 86 non-small cell lung cancer patients and 73 healthy subjects matched for gender and age were assessed with the Temperament and Character Inventory. In the patient group QOL was assessed with EORTC QLQ-C30. We used multiple linear regressions to determine whether personality dimensions predict HRQOL. Data on tumor stage, patient age, education and marital status were also collected.

Results

Lung cancer patients differed from healthy controls in the temperament dimension of persistence and the character dimension of self-transcendence. The temperament dimension of harm avoidance and the character dimension of cooperativeness were significant predictors of QOL functional scales and global health status.

Conclusions

In lung cancer patients, the personality dimensions of harm avoidance and cooperativeness showed associations with most QOL dimensions. Personality factors are relevant for patients' QOL perception and should be included in cancer patients' QOL assessment.

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort

BACKGROUND

The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension 'harm avoidance' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an 'oversampling' study design. Method Subjects consistently in either upper or lower quartiles for the HA trait were selected from a population-based cohort in Finland (n = 2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high- and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BPND) in high- and low-HA groups estimated with PET and [11C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([11C]MADAM). In secondary analyses, 5-HTT BPND was correlated with other TCI dimensions.

RESULTS

5-HTT BPND did not differ between high- and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BPND in the raphe nucleus predicted higher scores in 'self-directedness'.

CONCLUSIONS

This study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high 'self-directedness' (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.

Increased plasma norepinephrine concentration in psychotic depression

OBJECTIVE

We previously found psychotic depression (PSDEP) to have positively correlating plasma norepinephrine (NE) and vasopressin (AVP) concentrations. Since central noradrenergic activity and plasma NE concentration are highly correlated, this suggests an increased noradrenergic activation of the hypothalamus-pituitary-adrenal axis. We hypothesize the increased release of NE in PSDEP to be an associated mechanism.

METHODS

To test this hypothesis we analyzed the relation between plasma NE and PSDEP in a comparison with non-psychotically depressed patients. Potentially confounding variables were, among others, melancholia and two better validated subcategories in the field of melancholia and endogenous depression, three global dimensions of psychopathology - Emotional Dysregulation, Retardation and Anxiety - smoking habit, and different types of psychotropic and particularly antidepressant treatment. The data from nine patients with PSDEP and 69 patients with non-PSDEP were reanalysed.

RESULTS

Analysis of covariance controlling for the effects of tricyclic antidepressant treatment (≥100 mg) and smoking habit showed that PSDEP had an increased concentration of plasma NE. The previously found correlation between plasma NE and AVP was still present after correcting for the effects of confounding variables.

CONCLUSIONS

The results suggest an increased activity of the sympathetic nervous system in PSDEP that may act as a specific mechanism for increased vasopressinergic activation. This supports the view of PSDEP as a distinct subcategory of major depression.

Temperament and character in psychotic depression compared with other subcategories of depression and normal controls

Background. Support has been found for high harm avoidance as general vulnerability trait for depression and decreased self-directedness (SD) as central state-related personality change. Additional personality characteristics could be present in psychotic depression (PD). Increased noradrenergic activation in PD predicts the involvement of reward dependence (RD). Methods. The data during the acute episode and after full remission from the same subjects, that we used before, were reanalyzed. The dependence of the 7 dimensions of the Temperament and Character Inventory version 9 on PD, three other subcategories of depression, and a group of normal controls was tested by MANCOVA. Results. Low RD at both time points, and low Cooperativeness during the acute episode, were found as additional characteristics of PD. Conclusion. The combination of two premorbid temperaments, high HA and low RD, and the development of a state-related reduction of two character functions, SD and CO, may be the precondition for the development of combined depressive and psychotic psychopathology.

Association between monoamine oxidase A (MAOA) and personality traits in Japanese individuals

It has been reported that personality traits are related to several neurotransmitters. However, the association between personality traits and the central nervous system remains unclear. In the present study, we investigated the relationships between a polymorphism involving a variable number of tandem repeats in the promoter of the monoamine oxidase A (MAOA-VNTR) gene and personality traits, as assessed by the Temperament and Character Inventory (TCI). Promoter VNTRs in the MAOA were genotyped in 558 healthy Japanese individuals. Females homozygous for high-activity allele (4/4) had significantly higher persistence scores than those homozygous for the low-activity allele (3/3) (p=0.012, ANOVA). Meanwhile no difference in persistence was found between 3 and 4 allele in males. There were no differences between other scores of TCI subscales and MAOA-VNTR polymorphism. Our results suggest a gender-specific contribution of MAOA-VNTR polymorphism to persistence scores.

Association study between reward dependence temperament and a polymorphism in the phenylethanolamine N-methyltransferase gene in a Japanese female population

Cloninger's theory is that specific dimensions of temperament are associated with single neurotransmitter systems, and it is based on neurophysiologic and genetic approaches to the human traits. It suggests that overexpression of temperament could cause psychiatric illness. Based on this theory, we examined the correlation between reward dependence (RD) trait, measured with the Temperament and Character Inventory, and 5 polymorphisms in genes of norepinephrine pathways, ADRB1, COMT, PNMT, SLC18A1, and SLC6A2, in 85 Japanese female nursing students. We found that rs3764351 in PNMT was significantly associated with RD on Fisher's exact test (P = .029, P(corr) = .236). When haplotype analysis was performed for rs3764351 and rs876493 polymorphisms in the 5' flanking region of PNMT, 3 haplotypes were identified. Rs3764351 itself appeared to be correlated with RD in the present study of a specific population, although we could not demonstrate an association between RD and any of the haplotypes. Our findings have implications for the understanding of temperament using neurophysiologic approaches.

Association between cytochrome P450 (CYP) 2C19 polymorphisms and harm avoidance in Japanese

Polymorphic enzyme cytochrome P450 (CYP) 2C19 is expressed not only in the liver but also in the brain and mediates the biotransformation of 5-hydroxytriptamine (5-HT). We investigated possible association between genetic polymorphism of CYP2C19 and individual personality traits, possibly influenced by neurotransmitters. Mentally and physically healthy Japanese subjects were enrolled in this study (n = 352). Temperament and Character Inventory (TCI) and CYP2C19 genotyping were performed in all subjects. We detected CYP2C19*2 and *3 (http://www.imm.ki.se/CYPalleles/) using Amplichip CYP450 DNA tip. The number of genotypes classified as homozygous extensive metabolizer (EM), heterozygous EM, and poor metabolizer were 113, 181, and 58, respectively. Significant difference was found in TCI score in harm avoidance (HA; F = 3.138, P < 0.05). Post hoc analysis showed that TCI score in harm avoidance in homozygous EM was significantly lower than that in heterozygous EM (P < 0.05) or PM (P < 0.05). In sub-item analyses, HA3 (shyness with strangers, P < 0.01) and HA1 (anticipatory worry, P < 0.05) of TCI scores were significantly different among CYP2C19 genotypes. Meanwhile, there were no differences in TCI scores of novelty seeking (NS; F = 0.350, n.s.), reward dependence (RD; F = 1.080, n.s.), or persistence (P; F = 0.786, n.s.) among CYP2C19 genotypes. This study demonstrated that a significant association between CYP2C19 activity and HA is present in Japanese.

Habituation of P3a and P3b brain potentials in men engaged in extreme sports

Do person characteristics determine when novel, attention-grabbing stimuli loose their novelty? The aim of the present study was to investigate habituation of the visual event-related potentials (ERP) P3a and P3b in men that (1) were engaged in extreme sports, (2) had extremely high scores on the Impulsivity Sensation Seeking scale of the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ), yet were not engaged in extreme sports, or (3) had extremely low scores on ZKPQ. The results showed that P3a habituated significantly more in extreme sporters than in the other groups. The same was not found in comparison of the high and the low ZKPQ scorers. There were not differences between the groups in overall amplitude. It is concluded that ERP habituation may be more relevant than mere amplitude to the sensation seeking trait in extreme sporters, and that they differ from others in ERPs related to automatic alerting-related processes, not controlled cognitive processing.

Serotonin transporter protein polymorphism and harm avoidance personality in migraine without aura

OBJECTIVE

To investigate polymorphisms in the serotonin transporter protein gene and harm avoidance personality dimension in patients with migraine without aura (MWOA).

BACKGROUND

The serotonin transporter protein is a key modulator of serotonergic synaptic neurotransmission. Two polymorphic regions of the gene for serotonin transporter protein have been found, and are associated with variations in the functional activity of serotonin caused by differing transcriptional efficiency. The harm avoidance (HA) personality trait may also be heritable and associated with altered serotonergic neurotransmitter activity.

DESIGN

We amplified the polymorphism in the promoter of serotonin transporter protein (5-HTTLPR) and the variable number of tandem repeats polymorphism within intron 2 (VNTR) using the polymerase chain reaction and performed genotype polymorphism analyses in 97 patients with MWOA and 100 healthy controls. We investigated serotonin-related personality traits by evaluating the HA personality dimension using a tridimensional questionnaire.

RESULTS

The genotype frequencies and allele distributions of 5-HTTLPR did not differ between patients with MWOA and controls. The VNTR genotype STin2.12/STin2.12 was significantly more common in patients with MWOA (90%) than in controls (77%; P= .017). Patients with MWOA also had HA scores (21.9 +/- 6.4) significantly higher than those of controls (16.3 +/- 6.1; P < .001).

CONCLUSIONS

Serotonergic activity might be involved in the development of MWOA and VNTR of serotonin transporter gene might be one of the genetically contributing factors.

Monoamine oxidase A gene promoter polymorphism affects novelty seeking and reward dependence in healthy study participants

It has been suggested that monoamine oxidase A plays an important role in the characterization of personality. Previous studies on the association between the polymorphism of variable number tandem repeat in the promoter region of the monoamine oxidase A gene and personality traits have, however, been unproductive. In the present study, the association between the monoamine oxidase A variable number tandem repeat polymorphism and personality traits assessed by the Temperament and Character Inventory was examined in 324 Japanese volunteers without psychiatric disorders. The low activity allele with three repeats (allele 3) and high activity allele with four repeats (allele 4) were determined by a polymerase chain reaction method. The carriers of allele 3 in males and the homozygotes of allele 3 in females were classified as the low activity group, the heterozygotes of alleles 3 and 4 in females as the medium activity group, and the carriers of allele 4 in males and the homozygotes of allele 4 in females as the high activity group. One-way analysis of variance showed that the scores of novelty seeking (P=0.006) and reward dependence (P=0.013) were significantly higher in the high activity group than in the low activity group. Multiple regression analysis demonstrated that the excess in the high activity allele was significantly associated with higher scores of novelty seeking (P=0.004) and reward dependence (P=0.003). The present study thus suggests that the monoamine oxidase A variable number tandem repeat polymorphism affects novelty seeking and reward dependence in healthy study participants.

Personality traits as risk factors of depression and anxiety among Japanese students

The aim of this study is to examine the effects of personality (temperament and character) on specific depression and specific anxiety. A total of 541 Japanese undergraduates were investigated by using the Temperament and Character Inventory (TCI) and the Hospital Anxiety and Depression (HAD) scale. Hierarchical multiple regression analyses demonstrated that specific depression was predicted by lower Reward-Dependence, Persistence, Self-Directedness, Cooperativeness, and Self-Transcendence; specific anxiety was predicted by higher Novelty-Seeking, Harm-Avoidance, Persistence, and Self-Transcendence, and lower Self-Directedness. Immaturity of Self-Directedness is a risk factor for negative affectivity. Immaturity of all character dimensions is a risk factor for specific depression. The relationship between Harm-Avoidance and depression in previous studies may be linked partly to somatic symptoms that were deliberately eliminated in the HAD scale.

Serotonergic activity contributes to analgesic overuse in chronic tension-type headache

OBJECTIVE

To evaluate the possible existence of a genetically determined innate factor that could exert a profound influence on the development of analgesic overuse in chronic tension-type headache (CTTH).

BACKGROUND

Many patients with CTTHs report the regular use of analgesics. Continuous use of analgesics results in the ultimate worsening of headaches. The factors related to development of analgesic overuse, however, remain poorly understood. The genetic factors for serotonin metabolism and the harm avoidance (HA) personality dimension are known to be associated with various substance abuse patterns.

DESIGN

We performed serotonin transporter protein (5-HTT) gene-linked polymorphic region (5-HTTLPR) genotype polymorphism analyses, and investigated serotonin-related personality traits by assessing the HA dimension using tridimensional personality questionnaire, given to 48 patients with CTTHs and reported analgesic overuse (CTTH-AO), in 50 patients with CTTHs without analgesic overuse (CTTH-NO), and in 100 healthy controls. We compared their headache characteristics using standardized questionnaires.

RESULTS

We discovered an excess frequency of 5-HTTLPR short allele and a different genotypic distribution in patients with CTTH-AO. The S/S genotype frequency was significantly higher in patients with CTTH-AO (83%) than in CTTH-NO (72%) and control (59%; P= .010) groups. Patients with CTTH-AO exhibited the highest HA scores (23.3 +/- 5.4), as compared to CTTH-NO (19.9 +/- 6.7) and control (16.3 +/- 6.1) groups. Individuals with the S/S genotype showed a greater tendency toward analgesic overuse (13.3 +/- 11.3 days per month) than did those with the non-S/S genotype (7.0 +/- 8.6 days per month: P= .02).

CONCLUSIONS

Our data suggest that serotonergic activity may be involved in the development of analgesic overuse in CTTH and that 5-HTTLPR might be one of the genetically contributing factors.

Reward dependence is related to norepinephrine transporter T-182C gene polymorphism in a Korean population

It is well established that approximately 50% of the variance in personality traits is genetic. The goal of this study was to investigate a relationship between personality traits and the T-182C polymorphism in the norepinephrine transporter gene. The participants included 115 healthy adults with no history of psychiatric disorders and other physical illness during the past 6 months. All participants were tested with the Temperament and Character Inventory and genotyped norepinephrine transporter gene polymorphism. Differences on the Temperament and Character Inventory dimensions among three groups were examined with one-way analysis of variance. Our study suggests that the norepinephrine transporter T-182C gene polymorphism is associated with reward dependence in Koreans, but the small number of study participants and their sex and age heterogeneity limits generalization of our results. Further studies are necessary with a larger number of homogeneous participants to confirm whether the norepinephrine transporter gene is related to personality traits.

Psychometric Properties of the Temperament and Character Inventory–Revised (TCI–R) in a Belgian Sample

The Temperament and Character Inventory (TCI; Cloninger, Przybeck, Svrakic, & Wetzel, 1994) is a self-questionnaire developed to assess the 7 dimensions of personality described by Cloninger et al. (1994) with a total of 29 subscales. In 1999, a revised version was proposed by Cloninger (TCI-R). In this study, we present psychometric properties of the TCI-R from 958 French-speaking participants of Belgium. Women exhibited higher scores for harm avoidance, reward dependence, and cooperativeness dimensions. The proposed factorial structure of 4 temperament dimensions and 3 character dimensions was confirmed. The TCI-R inventory had good test-retest reliabilities as well as good alpha coefficients. The addition of 3 new subscales to the original scale for Persistence has produced a very reliable dimension in the TCI-R.

Serotonin transporter polymorphism and harm avoidance personality in chronic tension-type headache

OBJECTIVE

To investigate the 5-HTT-gene-linked polymorphic region (5-HTTLPR) genotypes and harm avoidance (HA) dimension in chronic tension-type headache (CTH).

BACKGROUND

Serotonin transporter protein (5-HTT) is a key modulating protein in synaptic serotonergic neurotransmission. Among serotonin gene-linked polymorphism, promoter located in the regulatory region of the 5-HTTLPR has two alleles (short and long) with different transcriptional efficiencies. The HA personality trait may be heritable and associated with serotonergic neurotransmitter activity.

DESIGN

We amplified the 5-HTTLPR by means of polymerase chain reaction and performed genotype polymorphism analyses and we investigated the serotonin-related personality trait by evaluating the HA dimension in tridimensional personality questionnaire (TPQ) in 107 patients with CTH and in 100 healthy controls.

RESULTS

We found an excess frequency of the short allele and a different genotype distribution in patients with CTH. S/S genotype frequency was significantly higher in patients with CTH (76%) than in those with controls (59%; P=.02). Patients with CTH had significantly higher HA scores (21.4+/6.3) than controls (16.3+/-6.1).

CONCLUSIONS

This suggests a serotonergic activity might be involved in the development of CTH and 5-HTTLPR might be one of the genetically contributing factors.

In vivo serotonin 5HT(2A) receptor binding and personality traits in healthy subjects: a positron emission tomography study

Using positron emission tomography (PET) and [(11)C]raclopride, an association between striatal D(2) dopamine receptors and emotional detachment has been recently reported. Several laboratory findings indicate a link between the serotoninergic system and harm avoidance. In this study we investigated, in a group of healthy volunteers, the relationship between the in vivo binding of 3-(2'-[(18)F]fluoroethyl)spiperone ([(18)F]FESP) to cortical 5HT(2) and striatal D(2) receptors and three personality dimensions, i.e., "novelty seeking," "reward dependence," and "harm avoidance." Eleven healthy volunteers were evaluated by means of the Tridimensional personality Questionnaire (C. R., Arch. Gen. Psychiatry 44: 573-588.) and underwent a PET scan with [(18)F]FESP. Harm avoidance showed a significant inverse correlation with [(18)F]FESP binding in the cerebral cortex, particularly in the frontal cortex (R(2) = -0.709, P = 0.0145) and left parietal cortex (R = -0.629, P = 0.038) but not in the basal ganglia (r = -0.176, P = 0.651). Similar results were obtained using SPM at a P threshold of 0.05. No significant correlation was observed with novelty seeking or reward dependence. In the cerebral cortex, high values of [(18)F]FESP binding values are associated with a high tendency to avoid danger, indicating involvement of the serotoninergic system and, in particular, 5HT(2A) receptors, in this trait of personality. The results of this as well as of previous studies on personality dimensions indicate the existence of a relationship between behavioral and neurobiological factors. In addition these results support the concept that the variability of PET data may be explained by neurochemical differences related to the prevalence of specific personality traits.

Norepinephrine transporter gene polymorphism is not associated with susceptibility to alcohol dependence

Abnormalities in monoamine neurotransmission have been implicated in the pathogenesis of alcoholism, mood disorders and schizophrenia. Murine norepinephrine transporter gene (NET) has been mapped to a region on chromosome 8 where a quantitative trait locus for ethanol sensitivity. Therefore we tested whether norepinephrine transporter (NET) gene variants confer susceptibility to either alcohol dependence or severe alcohol withdrawal symptoms. There is a highly polymorphic silent G1287A mutation in the NET gene. In our study 157 alcoholics and 185 healthy unrelated matched control subjects were analyzed for a silent G1287A mutation. No significant differences in allele and genotype distribution between control subjects f(A)=0.33 and alcoholics f(A)=0.29 were found. No significant results were found in more homogenous subgroups, i.e. alcoholics with severe alcohol withdrawal (seizures, delirium), early onset age<26 nor dependent patients with positive familial history of alcoholism. These results suggest that the NET gene polymorphism in exon 9 accession number: mRNA: NM_001043, genomic contig.: NT_019610, is unlikely to be involved in the susceptibility to alcoholism and severe alcohol withdrawal.

Norepinephrine transporter and alpha(2c) adrenoceptor allelic variants and personality factors

It has been suggested that reward dependence, as measured by the Tridimensional Personality Questionnaire (TPQ), is related to central noradrenergic activity, a proposition supported by two studies of urinary norepinephrine metabolite. In the current investigation, 190 normal young Han Chinese were examined, with genetic polymorphisms determined for the norepinephrine transporter (1287G/A) and the alpha(2c)-adrenoceptor (Del322-325) to test the association with TPQ personality traits. No significant association was demonstrated for these two polymorphisms and any of the TPQ personality-factor scores, including reward dependence and its subscales. Our negative findings suggest that the investigated polymorphisms of the norepinephrine transporter and the alpha(2c) adrenoceptor do not play a major role in the reward-dependence personality trait as assessed by TPQ.

Neurotransmitters, temperament and social functioning

Dimensional models can be usefully employed to describe both normal and disordered personality. Studies in molecular genetics, receptor binding, peripheral monoamines and pharmacological challenges have investigated the neurochemical basis of personality. Substantial evidence now exists to support a psychobiological model but the specificity of Cloninger's theory has not always been confirmed. Clinical studies have shown both temperament and character dimensions to improve with pharmacological treatment especially in treatment responders. Some personality changes are found to be independent of clinical effects and even to occur in normal subjects. Models of personality can help in predicting treatment outcome but individual dimensions may not be useful. It is hypothesised that social adaptation is related to the character dimensions and different sources of evidence link these to serotonergic actions. However, recent clinical studies have shown a specific effect of noradrenaline on self-perception and social motivation. Drugs with specific actions on different neurotransmitters may exert a distinctive pattern of effects on personality and social behaviour.

Nicotine as an Addictive Substance: A Critical Examination of the Basic Concepts and Empirical Evidence

The present review is a critical analysis of the concepts behind and the empirical data supporting the view that tobacco use represents an addiction to nicotine. It deals with general aspects of the notion of addiction, while concentrating on specific problems associated with incorporating nicotine into current frameworks. The notion of addiction suffers from unprecedented definitional difficulties. The definitions offered by various authorities are very different, even contradictory. Definitions that reasonably include nicotine are so broad and vague that they allow many trivial things, such as salt, sugar, and watching television, to be considered addictive. Definitions that exclude the trivia also exclude nicotine. The addiction hypothesis, in general, is strongly shaped by views that certain drugs bring about a molecular level subversion of rationality. The main human evidence for this is verbal reports of smokers who say that they can't quit. On the other hand, the existence of many millions of successful quitters suggests that most people can quit. Some smokers don't quit, but whether they can't is another matter. The addiction hypothesis would be greatly strengthened by the demonstration that any drug of abuse produces special changes in the brain. It has yet to be shown that any drug produces changes in the brain different from those produced by many innocuous substances and events. The effects of nicotine on the brain are similar to those of sugar, salt, exercise, and other harmless substances and events. Apart from numerous conceptual and definitional inadequacies with the addiction concept in general, the notion that nicotine is addictive lacks reasonable empirical support. Nicotine does not have the properties of reference drugs of abuse. There are so many findings that conflict so starkly with the view that nicotine is addictive that it increasingly appears that adhering to the nicotine addiction thesis is only defensible on extra-scientific grounds.

Aminergic tone correlates of migraine and tension-type headache: a study using the tridimensional personality questionnaire

BACKGROUND

Aminergic neurotransmitter activity has been studied in many neuropsychiatric diseases by means of a self-administered questionnaire proposed by Cloninger. Given that central aminergic modulation plays a major role in the pathophysiology of primary headaches, we investigated the personality dimensions related to aminergic neurotransmitter activity in patients with migraine and tension-type headache.

METHODS

From a consecutive series of 230 patients, we selected those presenting with migraine and tension-type headache according to the International Headache Society criteria. All patients were assessed by means of the Cloninger 100-item self-report Tridimensional Personality Questionnaire and a depression scale. The four dimensions of personality are novelty seeking (dopaminergic), harm avoidance (serotonergic), reward dependence (noradrenergic), and persistence (glutaminergic).

RESULTS

One hundred twenty-one patients presenting with migraine and 42 with tension-type headache were recruited. The results indicate significantly higher harm avoidance scores (P<.001) in both patients with migraine and those with tension-type headache than in controls. Furthermore, patients with migraine had a significantly low score in the novelty seeking dimension (P<.001). When we compared only the two groups of patients with headache, we found that the persistence dimension alone was significantly higher in patients with migraine than in those with tension-type headache (P<.05). No differences were observed either in the overall scores of the other personality dimensions or in the depression scale scores.

CONCLUSIONS

The Tridimensional Personality Questionnaire results support a role of the serotonergic system in both migraine and tension-type headache pathophysiology. A dysfunction of dopaminergic and glutaminergic tone seems to be a specific feature of migraine.

Correlation of duration of latent Toxoplasma gondii infection with personality changes in women

Many parasites induce characteristic changes in behavior of their hosts. In humans latent toxoplasmosis is associated with changes in personality profiles. It has been already shown that a decrease in superego strength is correlated with duration of toxoplasmosis in men. Here we studied changes in personality profiles with Cattell's 16 PF questionnaire in Toxoplasma-infected women. The changes were measured as differences in personality factors between Toxoplasma-infected subjects and uninfected controls of the same age. The low-rate changes were studied in 230 women diagnosed with acute toxoplasmosis during past 14 years. The results showed the correlation between duration of toxoplasmosis and level of factors G (high superego strength) and Q3 (high strength of self sentiment). The high-rate changes were estimated by measuring the correlation between level of Toxoplasma-antibody titers (which rapidly decline after the end of acute phase of toxoplasmosis) and personality factors in an experimental set of 55 young mothers with latent toxoplasmosis. Again, certain factors, namely A (affectothymia), F (surgence), G (high superego strength), H (parmia), and L (protension), correlated with the length of the infection. We suggest that the parasite induced the changes in the personality profiles of the women because of our observation of an increasingly different personality profile over time between women with latent infection and controls. The same evidence questions the view that women with a particular personality profile are more prone to acquisition of T. gondii infection.

Six basic dimensions of personality and a seventh factor of generalized dysfunctional personality: a diathesis system covering all personality disorders

The five-factor model (FFM) of personality has recently been claimed to be comprehensive for all dimensionally conceived personality disorders (PDs). This assumption is refuted on the grounds of a principal component analysis conducted for three basic factor inventories (FFPI, NEO-FFI, Hamburg Personality Inventory), 22 explorative facet scales for normal personality and a questionnaire inventory (Inventory of Clinical Personality Accentuations) of 24 PD scales. Seven substantial orthogonal Varimax factors were found explaining 73% of the total variance. The five factors of the FFM were replicated. In addition, a new basic factor 'risk and competition seeking' (basic dimension 'risk', BD-R) emerged replicating findings of Andresen. The massive seventh factor was substantially loaded by all 24 PD scales and interpreted as 'general dysfunctional personality' (GDP). Most of the highly loaded scales describe varying forms of cognitive aberration. Together with GDP, the six-factor model now explains about 73% of all PD scales, thus, a virtually comprehensive descriptive diathesis system is achieved. Without GDP and BD-R, only 25% can be accounted for by the FFM. Five of the six normal dimensions will be loaded with positive and negative signs by some PDs. Neuroticism (BD-N) is still unique regarding its positive substantial correlations with almost all PD scales. BD-N is also the only normal factor which is correlated with GDP at about 0.50. A geometric model for the relationships between basic and clinical factors is presented.