Linda L Carpenter

Brown University, Providence, RI, USA

Are you Linda L Carpenter?

Claim your profile

Publications (70)293.63 Total impact

  • Article: Early life stress is associated with greater default network deactivation during working memory in healthy controls: a preliminary report.
    [show abstract] [hide abstract]
    ABSTRACT: Early life stress (ELS) is a common risk factor for psychopathology, but there are few functional neuroimaging studies investigating its effects. In this preliminary study, we investigated the correlates of ELS exposure on the default network (DN) through measurements of task-associated DN deactivation. Data were analyzed from 19 subjects without psychiatric illness (10 with ELS). Subjects performed the working memory (WM) N-back task (including a 2-back WM and 0-back control condition) while undergoing functional MRI. We compared brain responses in the two groups across 5 bilateral DN regions using an a priori region of interest (ROI) analysis. The ELS group demonstrated significantly greater DN deactivation, observed in the right posterior cingulate cortex PCC, bilateral medial prefrontal cortex, left middle/superior frontal gyrus and right middle temporal region. These preliminary results indicate subjects with ELS demonstrate greater DN deactivations to WM challenges compared to non-ELS controls, potentially reflecting a biomarker of long-term effects of ELS exposure.
    Brain Imaging and Behavior 12/2012; · 1.66 Impact Factor
  • Article: Decreased default network connectivity is associated with early life stress in medication-free healthy adults.
    [show abstract] [hide abstract]
    ABSTRACT: Early life stress (ELS) is a significant risk factor for psychopathology, although there are few functional imaging studies investigating its effects. Previous literature suggests that ELS is associated with changes in structure and function in the medial prefrontal cortex (MPFC), which forms the main anterior node of the default network (DN). This study investigated the impact of ELS history on resting state DN connectivity, using seed-based correlation analyses (SCA) involving the posterior cingulate cortex (PCC). Data were analyzed from 22 adult subjects without psychiatric or medical illness (13 with and 9 without ELS); none were taking psychotropic medication. Relative to controls, the ELS group had significant decreases in DN connectivity, observed between the PCC seed and the MPFC and inferior temporal cortex. Further analyses revealed a trend-level increase in connectivity between the amygdala and MPFC associated with ELS history. In conclusion, this study found that subjects with ELS, in the absence of psychiatric illness and medication exposure, demonstrated decreased DN connectivity, and trend-level increases in connectivity between the amygdala and MPFC. These findings suggest that altered resting state connectivity is a correlate of stress exposure, rather than a product of medication or psychiatric morbidity.
    European neuropsychopharmacology: the journal of the European College of Neuropsychopharmacology 11/2012; · 3.68 Impact Factor
  • Article: Telomeres and Early-Life Stress: An Overview.
    [show abstract] [hide abstract]
    ABSTRACT: The long-term sequelae of adverse early-life experiences have long been a focus in psychiatry, with a historic neurobiological emphasis on physiological systems that are demonstrably stress-responsive, such as the hypothalamic-pituitary-adrenal axis and neuroimmune function. However, there has been increasing recognition in the general medical literature that such sequelae might encompass more pervasive alterations in health status and physiology. Recent findings in telomere biology have suggested a new avenue for exploring the adverse health effects of childhood maltreatment. Telomere length in proliferative tissues declines with cell replication and the effect can be accelerated by such factors as inflammation, oxidative stress, radiation, and toxins. Reduced telomere length, as a proxy for cellular aging, has been associated with numerous chronic somatic diseases that are generally considered to be diseases of aging, such as diabetes, cancer, and heart disease. More recently, shorter telomeres have been demonstrated in several psychiatric conditions, particularly depression. Sustained psychosocial stress of a variety of types in adulthood appears to be associated with shorter telomeres. Now, emerging work suggests a robust, and perhaps dose-dependent, relationship with early-life stress. These findings present new opportunities to reconceptualize the complex relationships between experience, physical and psychiatric disease, and aging.
    Biological psychiatry 07/2012; · 8.93 Impact Factor
  • Article: Childhood adversity and epigenetic modulation of the leukocyte glucocorticoid receptor: preliminary findings in healthy adults.
    [show abstract] [hide abstract]
    ABSTRACT: A history of early adverse experiences is an important risk factor for adult psychopathology. Changes in stress sensitivity and functioning of the hypothalamic-pituitary-adrenal (HPA) axis may underlie the association between stress and risk for psychiatric disorders. Preclinical work in rodents has linked low levels of maternal care to increased methylation of the promoter region of the glucocorticoid receptor (GR) gene, as well as to exaggerated hormonal and behavioral responses to stress. Recent studies have begun to examine whether early-life stress leads to epigenetic modifications of the GR gene in humans. We examined the degree of methylation of a region of the promoter of the human GR gene (NR3C1) in leukocyte DNA from 99 healthy adults. Participants reported on their childhood experiences of parental behavior, parental death or desertion, and childhood maltreatment. On a separate day, participants completed the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, a standardized neuroendocrine challenge test. Disruption or lack of adequate nurturing, as measured by parental loss, childhood maltreatment, and parental care, was associated with increased NR3C1 promoter methylation (p<.05). In addition, NR3C1 promoter methylation was linked to attenuated cortisol responses to the Dex/CRH test (p<.05). These findings suggest that childhood maltreatment or adversity may lead to epigenetic modifications of the human GR gene. Alterations in methylation of this gene could underlie the associations between childhood adversity, alterations in stress reactivity, and risk for psychopathology.
    PLoS ONE 01/2012; 7(1):e30148. · 4.09 Impact Factor
  • Source
    Article: The nicotinic acetylcholine receptor as a target for antidepressant drug development.
    [show abstract] [hide abstract]
    ABSTRACT: An important new area of antidepressant drug development involves targeting the nicotinic acetylcholine receptor (nAChR). This receptor, which is distributed widely in regions of the brain associated with depression, is also implicated in other important processes that are relevant to depression, such as stress and inflammation. The two classes of drugs that target nAChRs can be broadly divided into mecamylamine- and cytisine-based compounds. These drugs probably exert their effects via antagonism at α4β2 nAChRs, and strong preclinical data support the antidepressant efficacy of both classes when used in conjunction with other primary antidepressants (e.g., monoamine reuptake inhibitors). Although clinical data remain limited, preliminary results in this area constitute a compelling argument for further evaluation of the nAChR as a target for future antidepressant drug development.
    TheScientificWorldJOURNAL 01/2012; 2012:104105. · 1.66 Impact Factor
  • Article: Minimal heating of aneurysm clips during repetitive transcranial magnetic stimulation.
    Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 11/2011; 123(7):1471-3. · 3.12 Impact Factor
  • Article: A placebo-controlled study of sertraline's effect on cortisol response to the dexamethasone/corticotropin-releasing hormone test in healthy adults.
    [show abstract] [hide abstract]
    ABSTRACT: The dexamethasone/corticotropin-releasing hormone (Dex/CRH) test is a neuroendocrine probe involving serial blood sampling of cortisol during a standardized pharmacological challenge without inducing psychological distress in humans. Some past studies in depressed patients have shown a "normalization" or decrease in cortisol response to the Dex/CRH test following successful treatment with an antidepressant. Studies in nondepressed healthy adult samples have also shown aberrant cortisol reactivity to be associated with depression risk factors. These findings prompted research into the use of the Dex/CRH test as a tool for developing antidepressant drugs. In this study, the Dex/CRH test was evaluated with regard to its potential utility for drug development in nonclinical samples. The Dex/CRH test was administered before and after 6 weeks of blinded treatment with either sertraline 100 mg/day or matching placebo in 22 healthy adults (13 women, nine men). Cortisol response to the Dex/CRH test increased following treatment with standard doses of sertraline, compared to placebo, after controlling for age and sex. The observed pattern of change contrasts with results from published studies in depressed patients and with our initial hypothesis.
    Psychopharmacologia 05/2011; 218(2):371-9. · 4.08 Impact Factor
  • Article: Effect of childhood physical abuse on cortisol stress response.
    [show abstract] [hide abstract]
    ABSTRACT: Abuse and neglect are highly prevalent in children and have enduring neurobiological effects. Stressful early life environments perturb the hypothalamic-pituitary-adrenal (HPA) axis, which in turn may predispose to psychiatric disorders in adulthood. However, studies of childhood maltreatment and adult HPA function have not yet rigorously investigated the differential effects of maltreatment subtypes, including physical abuse. In this study, we sought to replicate our previous finding that childhood maltreatment was associated with attenuated cortisol responses to stress and determine whether the type of maltreatment was a determinant of the stress response. Salivary cortisol response to the Trier Social Stress Test (TSST) was examined in a non-clinical sample of women (n = 110). Subjects had no acute medical problems and were not seeking psychiatric treatment. Effects of five maltreatment types, as measured by the Childhood Trauma Questionnaire, on cortisol response to the TSST were investigated. To further examine the significant (p < 0.005) effect of one maltreatment type, women with childhood physical abuse (PA) (n = 20) were compared to those without past PA (n = 90). Women reporting childhood PA displayed a significantly blunted cortisol response to the TSST compared with subjects without PA, after controlling for estrogen use, age, other forms of maltreatment, and other potential confounds. There were no differences between PA and control groups with regard to physiological arousal during the stress challenge. In a non-clinical sample of women with minimal or no current psychopathology, physical abuse is associated with a blunted cortisol response to a psychosocial stress task.
    Psychopharmacologia 03/2011; 214(1):367-75. · 4.08 Impact Factor
  • Article: Variation in NGFB is associated with primary affective disorders in women.
    [show abstract] [hide abstract]
    ABSTRACT: Affective disorders (AFDs) are highly comorbid with substance dependence (SD) and both are genetically influenced. However, the specific etiology of the comorbidity is not well understood. We genotyped an array of 1,350 single nucleotide polymorphisms (SNPs) in or near 130 genes in 868 European-Americans (EAs), including 182 individuals with primary AFDs (PAFDs), 214 with SD comorbid with AFD (CAFD), and 472 screened controls. NGFB, which encodes nerve growth factor β and was represented in the array by 15 SNPs, showed the strongest evidence of association, but only among women with PAFDs. Six of the SNPs showed nominally significant association with PAFDs in women (P's = 0.0007-0.01); three (rs2856813, rs4332358, and rs10776799) were empirically significant based on 1,000,000 permutations (P's = 0.008-0.015). Seven haplotypes were significantly associated with PAFDs in women (P's = 0.0014-0.01), of which six were significant based on empirical permutation analysis (minimal P = 0.0045). Four diplotypes were significantly associated with PAFDs in women (global P's = 0.001-0.01). The specific diplotype GG-TC, reconstructed from rs2856813 and rs6678788, showed the strongest evidence of association with PAFDs in women (OR = 4.07, P = 4.2E-05). No SNPs or haplotypes were associated with PAFDs in men or with CAFDs in either sex. We conclude that variation in NGFB is a risk factor for PAFDs in women, but not for CAFD.
    American Journal of Medical Genetics Part B Neuropsychiatric Genetics 02/2011; 156B(4):401-12. · 3.70 Impact Factor
  • Article: Gene-environment interactions: early life stress and risk for depressive and anxiety disorders.
    [show abstract] [hide abstract]
    ABSTRACT: Prior reviews have examined how stress, broadly defined, interacts with genetic diathesis in the pathogenesis of internalizing (i.e., depressive and anxiety) disorders. Recent findings have suggested a unique role for early life stress (ELS) in the development of internalizing disorders, contributing to the rapid proliferation of research in this area. This paper critically reviews studies in humans examining gene-environment interaction (GxE) effects of ELS on the risk for depression and anxiety, primarily from a candidate gene perspective. Major methodological challenges that are unique to such studies are considered. The majority of published studies have focused on candidates that regulate the serotonin system, especially the serotonin transporter. More recent work has addressed interactions of ELS with candidates from the hypothalamic-pituitary-adrenal axis and neurotrophin system. Available studies vary greatly with respect to definitions of ELS, examination of gene-gene interactions, consideration of gender effects, and attention to analytic limitations. Overall, there is support for GxE effects of ELS on the risk for depressive and anxiety outcomes. Future studies of ELS in this context will require careful attention to methodologic considerations. Such studies would benefit from more systematic assessment of positive environmental factors (e.g., social support) and greater utilization of developmentally sensitive paradigms.
    Psychopharmacologia 01/2011; 214(1):175-96. · 4.08 Impact Factor
  • Article: Nicotinic acetylcholine receptors and depression: a review of the preclinical and clinical literature.
    [show abstract] [hide abstract]
    ABSTRACT: Many patients with depression fail to derive sufficient benefit from available treatment options, with up to a third never reaching remission despite multiple trials of appropriate treatment. Novel antidepressant agents are needed, and drugs targeting nicotinic acetylcholine receptors (nAChRs) appear to hold promise in this regard. nAChRs are involved in a variety of neurobiological systems implicated in the pathophysiology of depression. In addition to their role in cholinergic neurotransmission, they modulate dopamine function and influence inflammation and hypothalamic-pituitary-adrenal axis activity. Preclinical studies have suggested antidepressant-like effects of drugs targeting nAChRs, with the most consistent results observed with alpha4beta2 nAChR modulators such as varenicline and nonspecific nAChR antagonists such as mecamylamine. These agents appear to offer the most potential antidepressant-like efficacy when used in conjunction with other established antidepressant treatments. nAChR modulators also influence neural processes that appear to mediate the behavioral effects of antidepressants, such as hippocampal cell proliferation. Clinical evidence, while limited, shows preliminary efficacy for mecamylamine and varenicline. Taken together, the preclinical and clinical evidence suggests that drugs targeting nAChRs may represent an important new approach to the treatment of depression.
    Psychopharmacologia 09/2010; 212(1):1-12. · 4.08 Impact Factor
  • Article: Association between plasma IL-6 response to acute stress and early-life adversity in healthy adults.
    [show abstract] [hide abstract]
    ABSTRACT: Increased production of peripheral cytokines and other pro-inflammatory markers has been linked to psychiatric disorders such as major depressive disorder and post-traumatic stress disorder. Recent research has pointed to early-life stress, particularly childhood maltreatment, as an independent and preventable risk factor for systemic inflammation in adulthood. Some data suggest that adults with a history of childhood maltreatment exhibit a heightened inflammatory response to acute stress challenge. To further elucidate the relationship between childhood maltreatment and pro-inflammatory cytokine production, we examined plasma IL-6 response to the Trier Social Stress Test (TSST) in 69 healthy adult subjects without depression or post-traumatic stress disorder. Serial plasma IL-6 concentrations were measured during a standardized psychosocial stressor in n=19 subjects with moderate-severe childhood maltreatment (MAL), and n=50 controls without maltreatment (CTL), as indicated by self-ratings on the childhood trauma questionnaire (CTQ). CTQ total scores were positively correlated with overall change in IL-6 response, as well as the maximum IL-6 concentration during the TSST. Greater acute IL-6 release and higher IL-6 concentrations over time were observed for the MAL group relative to the CTL group. Inflammation may be an important developmental mediator linking adverse experiences in early life to poor adult physical and mental health. The results of this preliminary study warrant further investigation in a larger sample.
    Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 09/2010; 35(13):2617-23. · 6.99 Impact Factor
  • Article: In Response to "No Correlation Between Childhood Maltreatment and Telomere Length"
    Biological psychiatry 08/2010; · 8.93 Impact Factor
  • Article: Transcranial magnetic stimulation for medication-resistant depression.
    Agustin G Yip, Linda L Carpenter
    The Journal of Clinical Psychiatry 04/2010; 71(4):502-3. · 5.80 Impact Factor
  • Article: In Reply to: Childhood Maltreatment and Hypothalamic-Pituitary-Adrenal Axis Reactivity.
    Biological psychiatry 03/2010; · 8.93 Impact Factor
  • Article: The clinical correlates of reported childhood sexual abuse: an association between age at trauma onset and severity of depression and PTSD in adults.
    [show abstract] [hide abstract]
    ABSTRACT: This study investigated the relationship between the age of -self-reported sexual abuse occurrence and the development of post-traumatic stress disorder and/or depressive symptoms in adulthood. Subjects were evaluated for the presence of post-traumatic stress disorder and/or depressive symptoms as well as for a self-reported history of sexual abuse before the age of 18. Results found that relative risk of having severe post-traumatic stress disorder symptoms was 10 times higher in patients reporting sexual abuse after age 12 than in those reporting sexual abuse before age 12. Relative risk of having severe depressive symptoms was higher for those abused before the age of 12 than for those abused after the age of 12. Findings suggest that the impact of reported sexual abuse at different stages of development may lead to distinct psychiatric symptoms in adulthood.
    Journal of Child Sexual Abuse 03/2010; 19(2):156-70. · 0.75 Impact Factor
  • Article: Pharmacologic approaches to treatment resistant depression: a re-examination for the modern era.
    [show abstract] [hide abstract]
    ABSTRACT: Treatment-resistant depression (TRD) is common and debilitating. Initial treatment is often insufficient to achieve full remission in a given depressive episode, resulting in more frequent episodes, worsened severity, and major disability. Areas covered in this review: This review surveys literature on the diagnosis and pharmacological management of TRD in light of recent developments. Evidence regarding commonly used treatment options is critically examined and key recommendations are offered. The review ends by considering drugs acting on the melatonin, acetylcholine, and glutamate systems that hold promise as future options for TRD. Recent trends and research findings have impacted how the evidence supporting different approaches to TRD should be evaluated. For example, many earlier TRD studies employed tricyclics as the primary antidepressant, but tricyclics have now been superseded by selective serotonin reuptake inhibitors (SSRIs) in routine clinical practice. This deficiency has been addressed by the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, the largest effectiveness study of TRD ever conducted. However, design characteristics of the STAR*D study preclude simple comparisons with earlier studies. A shortcoming of most treatment recommendations for TRD is their reliance on older studies that do not reflect the current preeminence of SSRIs in clinical practice. This has distorted the prioritization of pharmacological strategies for TRD. Efforts to correct this distortion with effectiveness research, designed to better reflect current practice trends, require critical consideration of the strengths and limitations of this approach.
    Expert Opinion on Pharmacotherapy 02/2010; 11(5):709-22. · 3.20 Impact Factor
  • Article: Childhood maltreatment and telomere shortening: preliminary support for an effect of early stress on cellular aging.
    [show abstract] [hide abstract]
    ABSTRACT: Psychological stress and trauma are risk factors for several medical and psychiatric illnesses. Recent studies have implicated advanced cellular aging as a potential mechanism of this association. Telomeres, DNA repeats that cap the ends of chromosomes and promote stability, shorten progressively with each cell division; their length is a marker of biological aging. Based on previous evidence linking psychosocial stress to shorter telomere length, this study was designed to evaluate the effect of childhood adversity on telomere length. Thirty-one adults with no current or past major Axis I psychiatric disorder participated. Subjects reported on their history of childhood maltreatment and telomere length was measured from DNA extracted from frozen whole blood using quantitative polymerase chain reaction. Participants reporting a history of childhood maltreatment had significantly shorter telomeres than those who did not report a history of maltreatment. This finding was not due to effects of age, sex, smoking, body mass index, or other demographic factors. Analysis of subscales showed that both physical neglect and emotional neglect were significantly linked to telomere length. These results extend previous reports linking shortened leukocyte telomere length and caregiver stress to more remote stressful experiences in childhood and suggest that childhood maltreatment could influence cellular aging.
    Biological psychiatry 10/2009; 67(6):531-4. · 8.93 Impact Factor
  • Article: [Childhood maltreatment and adult psychopathology: pathways to hypothalamic-pituitary-adrenal axis dysfunction].
    [show abstract] [hide abstract]
    ABSTRACT: The aim of this paper was to examine the relationship between childhood maltreatment and adult psychopathology, as reflected in hypothalamic-pituitary-adrenal axis dysfunction. A selective review of the relevant literature was undertaken in order to identify key and illustrative research findings. There is now a substantial body of preclinical and clinical evidence derived from a variety of experimental paradigms showing how early-life stress is related to hypothalamic-pituitary-adrenal axis function and psychological state in adulthood, and how that relationship can be modulated by other factors. The risk for adult psychopathology and hypothalamic-pituitary-adrenal axis dysfunction is related to a complex interaction among multiple experiential factors, as well as to susceptibility genes that interact with those factors. Although acute hypothalamic-pituitary-adrenal axis responses to stress are generally adaptive, excessive responses can lead to deleterious effects. Early-life stress alters hypothalamic-pituitary-adrenal axis function and behavior, but the pattern of hypothalamic-pituitary-adrenal dysfunction and psychological outcome in adulthood reflect both the characteristics of the stressor and other modifying factors. Research to date has identified multiple determinants of the hypothalamic-pituitary-adrenal axis dysfunction seen in adults with a history of childhood maltreatment or other early-life stress. Further work is needed to establish whether hypothalamic-pituitary-adrenal axis abnormalities in this context can be used to develop risk endophenotypes for psychiatric and physical illnesses.
    Revista Brasileira de Psiquiatria 10/2009; 31 Suppl 2:S41-8. · 1.20 Impact Factor
  • Article: Interaction of childhood maltreatment with the corticotropin-releasing hormone receptor gene: effects on hypothalamic-pituitary-adrenal axis reactivity.
    [show abstract] [hide abstract]
    ABSTRACT: Variation in the corticotropin-releasing hormone receptor (CRHR1) gene has been shown to interact with early life stress to predict adult depression. This study was conducted to determine whether CRHR1 polymorphisms interact with childhood maltreatment to predict hypothalamic-pituitary-adrenal (HPA) axis reactivity, which has been linked to both depression and early life stress. One hundred twenty-nine White, non-Hispanic adults completed the Childhood Trauma Questionnaire and the dexamethasone/corticotropin-releasing hormone (DEX/CRH) test, and provided blood samples for genotyping of two CRHR1 polymorphisms. Both rs110402 and rs242924 (which were in tight linkage disequilibrium, D' = .98) showed a significant interaction with maltreatment in the prediction of cortisol response to the DEX/CRH test (p < .05). For subjects with maltreatment, the GG genotype of each single nucleotide polymorphism was associated with elevated cortisol responses to the test. Variation in the CRHR1 moderates the effect of childhood maltreatment on cortisol responses to the DEX/CRH test. Excessive HPA axis activation could represent a mechanism of interactions of risk genes with stress in the development of mood and anxiety disorders.
    Biological psychiatry 07/2009; 66(7):681-5. · 8.93 Impact Factor

Institutions

  • 2002–2012
    • Brown University
      • Department of Psychiatry and Human Behavior
      Providence, RI, USA
    • Alpert Medical School - Brown University
      • Department of Psychiatry and Human Behavior
      Providence, RI, USA
  • 2011
    • Memorial Hospital of Rhode Island
      Pawtucket, RI, USA
  • 2004–2011
    • Providence Hospital
      Mobile, AL, USA
  • 2009–2010
    • Universidade Federal de São Paulo
      Guarulhos, Estado de Sao Paulo, Brazil
  • 2003
    • Yale-New Haven Hospital
      New Haven, CT, USA