Jonathan Benjamin

Bio: Jonathan Benjamin is an academic researcher from Ben-Gurion University of the Negev. The author has contributed to research in topics: Personality & Anxiety. The author has an hindex of 32, co-authored 65 publications receiving 9812 citations. Previous affiliations of Jonathan Benjamin include Barzilai Medical Center & National Institutes of Health.

Association of Anxiety-Related Traits with a Polymorphism in the Serotonin Transporter Gene Regulatory Region

Abstract: Transporter-facilitated uptake of serotonin (5-hydroxytryptamine or 5-HT) has been implicated in anxiety in humans and animal models and is the site of action of widely used uptake-inhibiting antidepressant and antianxiety drugs. Human 5-HT transporter (5-HTT) gene transcription is modulated by a common polymorphism in its upstream regulatory region. The short variant of the polymorphism reduces the transcriptional efficiency of the 5-HTT gene promoter, resulting in decreased 5-HTT expression and 5-HT uptake in lymphoblasts. Association studies in two independent samples totaling 505 individuals revealed that the 5-HTT polymorphism accounts for 3 to 4 percent of total variation and 7 to 9 percent of inherited variance in anxiety-related personality traits in individuals as well as sibships.

Population and familial association between the D4 dopamine receptor gene and measures of Novelty Seeking

Abstract: Twin and adoption studies suggest that 30 to 60% of the variance in many personality traits is due to inherited factors. However, there is little knowledge of the number or identity of the responsible genes, how they differ between individuals, or how their gene products interact with the developing brain and with environmental and experiential factors to generate the complex blend of attitudes and actions that comprise human temperament1. In the accompanying paper, Ebstein et al.2 have found a population association between a long allele of polymorphic exon III repeat sequence of the D4 dopamine receptor gene (DADR) and the normal personality trait of Novelty Seeking. The possibility of a causal relationship between DADR and Novelty Seeking is further supported by studies showing that the number of exon III repeats can affect the binding of ligands to the receptor3,4; that DADR is expressed in lim-bic areas involved in cognition and emotion5,6; that dopamine mediates exploratory behaviour in experimental animals7–12; that the rewarding effects of amphetamines and cocaine are related to dopamine release13; and that Novelty Seeking is low in dopamine-deficient patients with Parkinson's disease14. We investigated the relationship between DADR exon III sequence variants and personality test scores in a population of 315 mostly male siblings, other family members and individuals from the United States. The association between long alleles of exon III and personality traits related to Novelty Seeking was confirmed. Moreover, family studies showed that this association is the result of genetic transmission rather than of population stratification.

Autonomic dysregulation in panic disorder and in post-traumatic stress disorder: application of power spectrum analysis of heart rate variability at rest and in response to recollection of trauma or panic attacks

Abstract: Power spectral analysis (PSA) of heart rate variability (HRV) offers reliable assessment of cardiovascular autonomic responses, providing a 'window' onto the interaction of peripheral sympathetic and parasympathetic tone Alterations in HRV are associated with various physiological and pathophysiological processes, and may contribute to morbidity and mortality Previous studies of posttraumatic stress disorder (PTSD) found lower resting HRV in patients compared to controls, suggesting increased sympathetic and decreased parasympathetic tone This article describes the analysis of HRV at rest and after psychological stress in panic disorder (PD) patients, in an enlarged sample of PTSD patients, and in healthy control subjects Standardized heart rate (HR) analysis was carried out in 14 PTSD patients, 11 PD patients and 25 matched controls ECG recordings were made while subjects were resting ('rest 1'), while recalling the trauma implicated in PTSD, or the circumstances of a severe panic attack, as appropriate ('recall'), and again while resting ('rest 2') Controls were asked to recall a stressful life event during recall While both patient groups had elevated HR and low frequency (LF) components of HRV at baseline (suggesting increased sympathetic activity), PTSD patients, unlike PD patients and controls, failed to respond to the recall stress with increases in HR and LF HRV analysis demonstrates significant differences in autonomic regulation of PTSD and PD patients compared to each other and to control subjects HRV analysis may augment biochemical studies of peripheral measures in these disorders

Association between the serotonin transporter promoter polymorphism and personality traits in a primarily female population sample

Abstract: The serotonin transporter (5-HTT) regulates serotonergic neurotransmission and is thought to influence emotion. A 5-HTT-linked polymorphic region (5-HTTLPR) has two common variants, short (s) and long (l). We previously found population and within-family associations between the lower-expressing s allele and neuroticism, a trait related to anxiety, hostility, and depression, on a standard measure (the NEO Personality Inventory, Revised [NEO-PI-R]) in a primarily male population (n=505), and that the s allele was dominant. We investigated this association in a new sample (n=397, 84% female, primarily sib-pairs). The results robustly replicated the 5-HTTLPR neuroticism association, and the dominance of the s allele. Combined data from the two studies (n=902) showed a highly significant association between the s allele and higher NEO Neuroticism both across individuals and within families. Association between genotype and a related measure, Anxiety on the 16PF inventory, was replicated in the new population and within families in the combined sample. Association to another trait, estimated TPQ Harm Avoidance, was not replicated in the new sample but found only within the combined sibship group. Another association found in our original study, between the s allele and lower scores on NEO-PI-R Agreeableness, was also replicated and was more robust in the current and the combined samples. Associations between the functional 5-HTTLPR polymorphism were similar in women and men. These results help to define specific personality features reproducibly associated with 5-HTTLPR genotype. Such associations were strongest for traits defined by the NEO, enhancing the attractiveness of the five-factor personality model in genetic research on complex behavioral dimensions. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:202–216, 2000. Published 2000 Wiley-Liss, Inc.

Effect of Prefrontal Repetitive Transcranial Magnetic Stimulation in Obsessive-Compulsive Disorder: A Preliminary Study

Abstract: Objective: Prefrontal mechanisms are implicated in obsessive-compulsive disorder. The authors investigated whether prefrontal repetitive transcranial magnetic stimulation influenced obsessive-compulsive disorder symptoms. Method: Twelve patients with obsessive-compulsive disorder were given repetitive transcranial magnetic stimulation (80% motor threshold, 20 Hz/2 seconds per minute for 20 minutes) to a right lateral prefrontal, a left lateral prefrontal, and a midoccipital (control) site on separate days, randomized. The patients’ symptoms and mood were rated for 8 hours afterward. Results: Compulsive urges decreased significantly for 8 hours after right lateral prefrontal repetitive transcranial magnetic stimulation, but there were nonsignificant increases in compulsive urges after repetitive transcranial magnetic stimulation of the midoccipital site. A shorter-lasting (30 minutes), modest, and nonsignificant reduction in compulsive urges occurred after left lateral prefrontal repetitive transcranial magnetic stimulation. Mood improved during and 30 minutes after right lateral prefrontal stimulation. Conclusions: These preliminary results suggest that right prefrontal repetitive transcranial magnetic stimulation might affect prefrontal mechanisms involved in obsessive-compulsive disorder. (Am J Psychiatry 1997; 154:867‐869)

The Big Five Trait taxonomy: History, measurement, and theoretical perspectives.

Abstract: 2 Taxonomy is always a contentious issue because the world does not come to us in neat little packages (S. Personality has been conceptualized from a variety of theoretical perspectives, and at various levels of Each of these levels has made unique contributions to our understanding of individual differences in behavior and experience. However, the number of personality traits, and scales designed to measure them, escalated without an end in sight (Goldberg, 1971). Researchers, as well as practitioners in the field of personality assessment, were faced with a bewildering array of personality scales from which to choose, with little guidance and no overall rationale at hand. What made matters worse was that scales with the same name often measure concepts that are not the same, and scales with different names often measure concepts that are quite similar. Although diversity and scientific pluralism are useful, the systematic accumulation of findings and the communication among researchers became difficult amidst the Babel of concepts and scales. Many personality researchers had hoped that they might devise the structure that would transform the Babel into a community speaking a common language. However, such an integration was not to be achieved by any one researcher or by any one theoretical perspective. As Allport once put it, " each assessor has his own pet units and uses a pet battery of diagnostic devices " (1958, p. 258). What personality psychology needed was a descriptive model, or taxonomy, of its subject matter. One of the central goals of scientific taxonomies is the definition of overarching domains within which large numbers of specific instances can be understood in a simplified way. Thus, in personality psychology, a taxonomy would permit researchers to study specified domains of personality characteristics, rather than examining separately the thousands of particular attributes that make human beings individual and unique. Moreover, a generally accepted taxonomy would greatly facilitate the accumulation and communication of empirical findings by offering a standard vocabulary, or nomenclature. After decades of research, the field is approaching consensus on a general taxonomy of personality traits, the " Big Five " personality dimensions. These dimensions do not represent a particular theoretical perspective but were derived from analyses of the natural-language terms people use to describe themselves 3 and others. Rather than replacing all previous systems, the Big Five taxonomy serves an integrative function because it can represent the various and diverse systems of personality …

Influence of Life Stress on Depression: Moderation by a Polymorphism in the 5-HTT Gene

Abstract: In a prospective-longitudinal study of a representative birth cohort, we tested why stressful experiences lead to depression in some people but not in others. A functional polymorphism in the promoter region of the serotonin transporter (5-HT T) gene was found to moderate the influence of stressful life events on depression. Individuals with one or two copies of the short allele of the 5-HT T promoter polymorphism exhibited more depressive symptoms, diagnosable depression, and suicidality in relation to stressful life events than individuals homozygous for the long allele. This epidemiological study thus provides evidence of a gene-by-environment interaction, in which an individual's response to environmental insults is moderated by his or her genetic makeup.

Association of Anxiety-Related Traits with a Polymorphism in the Serotonin Transporter Gene Regulatory Region

Abstract: Transporter-facilitated uptake of serotonin (5-hydroxytryptamine or 5-HT) has been implicated in anxiety in humans and animal models and is the site of action of widely used uptake-inhibiting antidepressant and antianxiety drugs. Human 5-HT transporter (5-HTT) gene transcription is modulated by a common polymorphism in its upstream regulatory region. The short variant of the polymorphism reduces the transcriptional efficiency of the 5-HTT gene promoter, resulting in decreased 5-HTT expression and 5-HT uptake in lymphoblasts. Association studies in two independent samples totaling 505 individuals revealed that the 5-HTT polymorphism accounts for 3 to 4 percent of total variation and 7 to 9 percent of inherited variance in anxiety-related personality traits in individuals as well as sibships.

The World Mental Health (WMH) Survey Initiative Version of the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI).

Abstract: This paper presents an overview of the World Mental Health (WMH) Survey Initiative version of the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI) and a discussion of the methodological research on which the development of the instrument was based. The WMH-CIDI includes a screening module and 40 sections that focus on diagnoses (22 sections), functioning (four sections), treatment (two sections), risk factors (four sections), socio-demographic correlates (seven sections), and methodological factors (two sections). Innovations compared to earlier versions of the CIDI include expansion of the diagnostic sections, a focus on 12-month as well as lifetime disorders in the same interview, detailed assessment of clinical severity, and inclusion of information on treatment, risk factors, and consequences. A computer-assisted version of the interview is available along with a direct data entry software system that can be used to keypunch responses to the paper-and-pencil version of the interview. Computer programs that generate diagnoses are also available based on both ICD-10 and DSM-IV criteria. Elaborate CD-ROM-based training materials are available to teach interviewers how to administer the interview as well as to teach supervisors how to monitor the quality of data collection.