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1.
JAMA Psychiatry ; 81(6): 545-554, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38381417

RESUMEN

Importance: Current interventions for posttraumatic stress disorder (PTSD) are efficacious, yet effectiveness may be limited by adverse effects and high withdrawal rates. Acupuncture is an emerging intervention with positive preliminary data for PTSD. Objective: To compare verum acupuncture with sham acupuncture (minimal needling) on clinical and physiological outcomes. Design, Setting, and Participants: This was a 2-arm, parallel-group, prospective blinded randomized clinical trial hypothesizing superiority of verum to sham acupuncture. The study was conducted at a single outpatient-based site, the Tibor Rubin VA Medical Center in Long Beach, California, with recruitment from April 2018 to May 2022, followed by a 15-week treatment period. Following exclusion for characteristics that are known PTSD treatment confounds, might affect biological assessment, indicate past nonadherence or treatment resistance, or indicate risk of harm, 93 treatment-seeking combat veterans with PTSD aged 18 to 55 years were allocated to group by adaptive randomization and 71 participants completed the intervention protocols. Interventions: Verum and sham were provided as 1-hour sessions, twice weekly, and participants were given 15 weeks to complete up to 24 sessions. Main Outcomes and Measures: The primary outcome was pretreatment to posttreatment change in PTSD symptom severity on the Clinician-Administered PTSD Scale-5 (CAPS-5). The secondary outcome was pretreatment to posttreatment change in fear-conditioned extinction, assessed by fear-potentiated startle response. Outcomes were assessed at pretreatment, midtreatment, and posttreatment. General linear models comparing within- and between-group were analyzed in both intention-to-treat (ITT) and treatment-completed models. Results: A total of 85 male and 8 female veterans (mean [SD] age, 39.2 [8.5] years) were randomized. There was a large treatment effect of verum (Cohen d, 1.17), a moderate effect of sham (d, 0.67), and a moderate between-group effect favoring verum (mean [SD] Δ, 7.1 [11.8]; t90 = 2.87, d, 0.63; P = .005) in the intention-to-treat analysis. The effect pattern was similar in the treatment-completed analysis: verum d, 1.53; sham d, 0.86; between-group mean (SD) Δ, 7.4 (11.7); t69 = 2.64; d, 0.63; P = .01). There was a significant pretreatment to posttreatment reduction of fear-potentiated startle during extinction (ie, better fear extinction) in the verum but not the sham group and a significant correlation (r = 0.31) between symptom reduction and fear extinction. Withdrawal rates were low. Conclusions and Relevance: The acupuncture intervention used in this study was clinically efficacious and favorably affected the psychobiology of PTSD in combat veterans. These data build on extant literature and suggest that clinical implementation of acupuncture for PTSD, along with further research about comparative efficacy, durability, and mechanisms of effects, is warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT02869646.


Asunto(s)
Trastornos de Combate , Trastornos por Estrés Postraumático , Veteranos , Humanos , Adulto , Masculino , Trastornos por Estrés Postraumático/terapia , Femenino , Persona de Mediana Edad , Trastornos de Combate/terapia , Trastornos de Combate/psicología , Veteranos/psicología , Adulto Joven , Resultado del Tratamiento , Terapia por Acupuntura/métodos , Reflejo de Sobresalto/fisiología , Estudios Prospectivos , Acupuntura Auricular/métodos
2.
Trials ; 22(1): 594, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34488824

RESUMEN

BACKGROUND: Post-traumatic stress disorder (PTSD) is a significant public health problem, affecting approximately 7% of the general population and 13-18% of the combat Veteran population. The first study using acupuncture for PTSD in a civilian population showed large pre- to post-treatment effects for an empirically developed verum protocol, which was equivalent to group cognitive behavior therapy and superior to a wait-list control. The primary objective of this study is to determine both clinical and biological effects of verum acupuncture for combat-related PTSD in treatment-seeking US Veterans. METHODS: This is a two-arm, parallel-group, prospective randomized placebo-controlled clinical trial. The experimental condition is verum acupuncture and the placebo control is sham (minimal) acupuncture in 1-h sessions, twice a week for 12 weeks. Ninety subjects will provide adequate power and will be allocated to group by an adaptive randomization procedure. The primary outcome is change in PTSD symptom severity from pre- to post-treatment. The secondary biological outcome is change from pre- to post-treatment in psychophysiological response, startle by electromyographic (EMG) eyeblink. Assessments will be conducted at pre-, mid-, post-, and 1-month post-treatment, blind to group allocation. Intent-to-treat analyses will be conducted. DISCUSSION: The study results will be definitive because both clinical and biological outcomes will be assessed and correlated. Issues such as the number needed for recruitment and improvement, use of sham acupuncture, choice of biological measure, and future research need will be discussed. TRIAL REGISTRATION: ClinicalTrials.gov NCT02869646 . Registered on 17 August 2016.


Asunto(s)
Terapia por Acupuntura , Trastornos por Estrés Postraumático , Veteranos , Terapia por Acupuntura/efectos adversos , Humanos , Estudios Prospectivos , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/terapia , Resultado del Tratamiento
3.
Psychoneuroendocrinology ; 119: 104749, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32554173

RESUMEN

Posttraumatic stress disorder (PTSD) is associated with dysregulation of the neuroendocrine system, including cortisol, allopregnanolone, and pregnanolone. Preliminary evidence from animal models suggests that baseline levels of these biomarkers may predict response to PTSD treatment. We report the change in biomarkers over the course of PTSD treatment. Biomarkers were sampled from individuals participating in (1) a randomized controlled trial comparing a web-version of Prolonged Exposure (Web-PE) therapy to in-person Present-Centered Therapy (PCT) and (2) from individuals participating in a nonrandomized effectiveness study testing PE delivered in-person as part of an intensive outpatient PTSD program. We found that higher cortisol reactivity during script-driven imagery was associated with higher baseline PTSD severity and that baseline allopregnanolone, pregnanolone, and cortisol reactivity were associated with PTSD treatment responder status over the course of intensive outpatient treatment. These findings demonstrate that peripherally assessed biomarkers are associated with PTSD severity and likelihood of successful treatment outcome of PE delivered daily over two weeks. These assessments could be used to determine which patients are likely to respond to treatment and which patients require augmentation to increase the likelihood of optimal response to PTSD treatment.


Asunto(s)
Biomarcadores/metabolismo , Terapia Implosiva , Personal Militar , Sistemas Neurosecretores/metabolismo , Trastornos por Estrés Postraumático/terapia , Adulto , Campaña Afgana 2001- , Biomarcadores/análisis , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Hidrocortisona/análisis , Hidrocortisona/metabolismo , Terapia Implosiva/métodos , Guerra de Irak 2003-2011 , Masculino , Persona de Mediana Edad , Personal Militar/psicología , Saliva/química , Saliva/metabolismo , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/metabolismo , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos
4.
Am J Physiol Heart Circ Physiol ; 315(1): H141-H149, 2018 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-29652544

RESUMEN

Patients with posttraumatic stress disorder (PTSD) have elevated sympathetic nervous system reactivity and impaired sympathetic and cardiovagal baroreflex sensitivity (BRS). Device-guided slow breathing (DGB) has been shown to lower blood pressure (BP) and sympathetic activity in other patient populations. We hypothesized that DGB acutely lowers BP, heart rate (HR), and improves BRS in PTSD. In 23 prehypertensive veterans with PTSD, we measured continuous BP, ECG, and muscle sympathetic nerve activity (MSNA) at rest and during 15 min of DGB at 5 breaths/min ( n = 13) or identical sham device breathing at normal rates of 14 breaths/min (sham; n = 10). Sympathetic and cardiovagal BRS was quantified using pharmacological manipulation of BP via the modified Oxford technique at baseline and during the last 5 min of DGB or sham. There was a significant reduction in systolic BP (by -9 ± 2 mmHg, P < 0.001), diastolic BP (by -3 ± 1 mmHg, P = 0.019), mean arterial pressure (by -4 ± 1 mmHg, P = 0.002), and MSNA burst frequency (by -7.8 ± 2.1 bursts/min, P = 0.004) with DGB but no significant change in HR ( P > 0.05). Within the sham group, there was no significant change in diastolic BP, mean arterial pressure, HR, or MSNA burst frequency, but there was a small but significant decrease in systolic BP ( P = 0.034) and MSNA burst incidence ( P = 0.033). Sympathetic BRS increased significantly in the DGB group (-1.08 ± 0.25 to -2.29 ± 0.24 bursts·100 heart beats-1·mmHg-1, P = 0.014) but decreased in the sham group (-1.58 ± 0.34 to -0.82 ± 0.28 bursts·100 heart beats-1·mmHg-1, P = 0.025) (time × device, P = 0.001). There was no significant difference in the change in cardiovagal BRS between the groups (time × device, P = 0.496). DGB acutely lowers BP and MSNA and improves sympathetic but not cardiovagal BRS in prehypertensive veterans with PTSD. NEW & NOTEWORTHY Posttraumatic stress disorder is characterized by augmented sympathetic reactivity, impaired baroreflex sensitivity, and an increased risk for developing hypertension and cardiovascular disease. This is the first study to examine the potential beneficial effects of device-guided slow breathing on hemodynamics, sympathetic activity, and arterial baroreflex sensitivity in prehypertensive veterans with posttraumatic stress disorder.


Asunto(s)
Barorreflejo , Ejercicios Respiratorios/métodos , Trastornos por Estrés Postraumático/terapia , Sistema Nervioso Simpático/fisiopatología , Adulto , Ejercicios Respiratorios/instrumentación , Femenino , Hemodinámica , Humanos , Masculino , Trastornos por Estrés Postraumático/fisiopatología
5.
Brain Behav Immun ; 61: 176-183, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27884623

RESUMEN

Toxoplasma gondii (TOXO) is a neuroinvasive protozoan parasite that induces the formation of persistent cysts in mammalian brains. It infects approximately 1.1million people in the United States annually. Latent TOXO infection is implicated in the etiology of psychiatric disorders, especially schizophrenia (SCZ), and has been correlated with modestly impaired cognition. The acoustic startle response (ASR) is a reflex seen in all mammals. It is mediated by a simple subcortical circuit, and provides an indicator of neural function. We previously reported the association of TOXO with slowed acoustic startle latency, an index of neural processing speed, in a sample of schizophrenia and healthy control subjects. The alterations in neurobiology with TOXO latent infection may not be specific to schizophrenia. Therefore we examined TOXO in relation to acoustic startle in an urban, predominately African American, population with mixed psychiatric diagnoses, and healthy controls. Physiological and diagnostic data along with blood samples were collected from 364 outpatients treated at an inner-city hospital. TOXO status was determined with an ELISA assay for TOXO-specific IgG. A discrete titer was calculated based on standard cut-points as an indicator of seropositivity, and the TOXO-specific IgG concentration served as serointensity. A series of linear regression models were used to assess the association of TOXO seropositivity and serointensity with ASR magnitude and latency in models adjusting for demographics and psychiatric diagnoses (PTSD, major depression, schizophrenia, psychosis, substance abuse). ASR magnitude was 11.5% higher in TOXO seropositive subjects compared to seronegative individuals (p=0.01). This effect was more pronounced in models with TOXO serointensity that adjusted for sociodemographic covariates (F=7.41, p=0.0068; F=10.05, p=0.0017), and remained significant when psychiatric diagnoses were stepped into the models. TOXO showed no association with startle latency (t=0.49, p=0.63) in an unadjusted model, nor was TOXO associated with latency in models that included demographic factors. After stepping in individual psychiatric disorders, we found a significant association of latency with a diagnosis of PTSD (F=5.15, p=0.024), but no other psychiatric diagnoses, such that subjects with PTSD had longer startle latency. The mechanism by which TOXO infection is associated with high startle magnitude is not known, but possible mechanisms include TOXO cyst burden in the brain, parasite recrudescence, or molecular mimicry of a host epitope by TOXO. Future studies will focus on the neurobiology underlying the effects of latent TOXO infection as a potential inroad to the development of novel treatment targets for psychiatric disease.


Asunto(s)
Reflejo de Sobresalto/inmunología , Medio Social , Toxoplasma/inmunología , Toxoplasmosis/inmunología , Población Urbana , Estimulación Acústica , Adulto , Negro o Afroamericano , Femenino , Humanos , Masculino , Persona de Mediana Edad
6.
Stud Health Technol Inform ; 191: 115-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23792855

RESUMEN

Posttraumatic stress disorder (PTSD) is a significant health concern for U.S. military service members (SMs) returning from Afghanistan and Iraq. Early intervention to prevent chronic disability requires greater understanding of subthreshold PTSD symptoms, which are associated with impaired physical health, mental health, and risk for delayed onset PTSD. We report a comparison of physiologic responses for recently deployed SMs with high and low subthreshold PTSD symptoms, respectively, to a fear conditioning task and novel virtual reality paradigm (Virtual Iraq). The high symptom group demonstrated elevated heart rate (HR) response during fear conditioning. Virtual reality sequences evoked significant HR responses which predicted variance of the PTSD Checklist-Military Version self-report. Our results support the value of physiologic assessment during fear conditioning and combat-related virtual reality exposure as complementary tools in detecting subthreshold PTSD symptoms in Veterans.


Asunto(s)
Trastornos de Combate/diagnóstico , Trastornos de Combate/fisiopatología , Miedo , Frecuencia Cardíaca , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/fisiopatología , Interfaz Usuario-Computador , Adulto , Campaña Afgana 2001- , Biorretroalimentación Psicológica/métodos , Trastornos de Combate/psicología , Condicionamiento Clásico , Femenino , Humanos , Guerra de Irak 2003-2011 , Masculino , Personal Militar/psicología , Trastornos por Estrés Postraumático/psicología , Adulto Joven
7.
Psychosom Med ; 74(2): 153-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22286850

RESUMEN

OBJECTIVE: Trauma is associated with increased risk for anxiety disorders such as posttraumatic stress disorder (PTSD). To further understand biologic mechanisms of PTSD, we examined the dark-enhanced startle response, a psychophysiological correlate of anxiety, and heart rate variability (HRV) in traumatized individuals with and without PTSD. The associations of these measures with PTSD may be sex-specific because of their associations with the bed nucleus of the stria terminalis, a sexually dimorphic brain structure in the limbic system that is approximately 2.5 times larger in men than in women. METHODS: The study sample (N = 141) was recruited from a highly traumatized civilian population seeking treatment at Grady Memorial Hospital in Atlanta, Georgia. Psychophysiological responses during a dark-enhanced startle paradigm task included startle magnitude, assessed by eyeblink reflex, and measures of high-frequency HRV, during light and dark phases of the startle session. RESULTS: The startle magnitude was higher during the dark phase than the light phase (mean ± standard error = 98.61 ± 10.68 versus 73.93 ± 8.21 µV, p < .001). PTSD was associated with a greater degree of dark-enhanced startle in women (p = .03) but not in men (p = .38, p interaction = .48). Although HRV measures did not differ between phases, high-frequency HRV was greater in men with PTSD compared with men without PTSD (p = .02). CONCLUSIONS: This study demonstrates that the dark-enhanced paradigm provides novel insights into the psychophysiological responses associated with PTSD in traumatized civilian sample. Sex differences in altered parasympathetic and sympathetic function during anxiety regulation tasks may provide further insight into the neurobiological mechanisms of PTSD.


Asunto(s)
Ansiedad/fisiopatología , Frecuencia Cardíaca/fisiología , Reflejo de Sobresalto/fisiología , Núcleos Septales/fisiología , Trastornos por Estrés Postraumático/fisiopatología , Estimulación Acústica , Adolescente , Adulto , Negro o Afroamericano , Anciano , Análisis de Varianza , Nivel de Alerta/fisiología , Arritmia Sinusal/fisiopatología , Parpadeo , Oscuridad , Femenino , Humanos , Acontecimientos que Cambian la Vida , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Frecuencia Respiratoria/fisiología , Núcleos Septales/anatomía & histología , Caracteres Sexuales , Adulto Joven
8.
Psychopharmacology (Berl) ; 215(1): 93-103, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21161186

RESUMEN

RATIONALE: Chronic cocaine use results in long-lasting neurochemical changes that persist beyond the acute withdrawal period. Previous work from our group reported a profound reduction in the acoustic startle response (ASR) in chronic cocaine-dependent subjects in early abstinence compared to healthy controls that may be related to long-lasting neuroadaptations following withdrawal from chronic cocaine use. OBJECTIVES: This study aims to investigate the persistence and time course of the decrements in the ASR of cocaine-dependent subjects during prolonged abstinence. METHODS: Seventy-six cocaine-dependent (COC) subjects and 30 controls (CONT) were tested, the former after a period of heavy cocaine dependence. COC subjects were retested sequentially for 1 year of abstinence or until relapse. ASR testing was conducted at 3-dB levels and the eye-blink component of the startle response was quantified with electromyographic recording of the orbicularis oculi muscle. RESULTS: While there was no difference in startle magnitude between CONT and COC in early abstinence, by day 40 of abstinence COC subjects exhibited a statistically significant decline (p = 0.0057) in ASR magnitude as compared with CONT and this decrement persisted for up to 1 year of abstinence (p = 0.0165). In addition, startle latency was slower in COC subjects as compared with CONT at all stages of abstinence. CONCLUSIONS: These results replicate and expand upon the earlier finding that chronic cocaine use impairs the ASR in a manner that persists beyond the acute withdrawal period. This phenomenon may represent a biological measure of long-term neural changes accompanying cocaine dependence and subsequent withdrawal.


Asunto(s)
Trastornos Relacionados con Cocaína/fisiopatología , Cocaína/efectos adversos , Filtrado Sensorial/fisiología , Síndrome de Abstinencia a Sustancias/fisiopatología , Estimulación Acústica , Parpadeo/efectos de los fármacos , Parpadeo/fisiología , Trastornos Relacionados con Cocaína/metabolismo , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tiempo de Reacción/efectos de los fármacos , Tiempo de Reacción/fisiología , Recurrencia , Filtrado Sensorial/efectos de los fármacos , Síndrome de Abstinencia a Sustancias/metabolismo
9.
J Pharmacol Exp Ther ; 332(2): 612-21, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19855096

RESUMEN

Lobeline is currently being evaluated in clinical trials as a methamphetamine abuse treatment. Lobeline interacts with nicotinic receptor subtypes, dopamine transporters (DATs), and vesicular monoamine transporters (VMAT2s). Methamphetamine inhibits VMAT2 and promotes dopamine (DA) release from synaptic vesicles, resulting ultimately in increased extracellular DA. The present study generated structure-activity relationships by defunctionalizing the lobeline molecule and determining effects on [(3)H]dihydrotetrabenazine binding, inhibition of [(3)H]DA uptake into striatal synaptic vesicles and synaptosomes, the mechanism of VMAT2 inhibition, and inhibition of methamphetamine-evoked DA release. Compared with lobeline, the analogs exhibited greater potency inhibiting DA transporter (DAT) function. Saturated analogs, lobelane and nor-lobelane, exhibited high potency (K(i) = 45 nM) inhibiting vesicular [(3)H]DA uptake, and lobelane competitively inhibited VMAT2 function. Lobeline and lobelane exhibited 67- and 35-fold greater potency, respectively, in inhibiting VMAT2 function compared to DAT function. Lobelane potently decreased (IC(50) = 0.65 microM; I(max) = 73%) methamphetamine-evoked DA overflow, and with a greater maximal effect compared with lobeline (IC(50) = 0.42 microM, I(max) = 56.1%). These results provide support for VMAT2 as a target for inhibition of methamphetamine effects. Both trans-isomers and demethylated analogs of lobelane had reduced or unaltered potency inhibiting VMAT2 function and lower maximal inhibition of methamphetamine-evoked DA release compared with lobelane. Thus, defunctionalization, cis-stereochemistry of the side chains, and presence of the piperidino N-methyl are structural features that afford greatest inhibition of methamphetamine-evoked DA release and enhancement of selectivity for VMAT2. The current results reveal that lobelane, a selective VMAT2 inhibitor, inhibits methamphetamine-evoked DA release and is a promising lead for the development of a pharmacotherapeutic for methamphetamine abuse.


Asunto(s)
Dopamina/metabolismo , Lobelina/análogos & derivados , Metanfetamina/farmacología , Proteínas de Transporte Vesicular de Monoaminas/antagonistas & inhibidores , Ácido 3,4-Dihidroxifenilacético/metabolismo , Trastornos Relacionados con Anfetaminas/tratamiento farmacológico , Animales , Cuerpo Estriado/efectos de los fármacos , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/antagonistas & inhibidores , Evaluación Preclínica de Medicamentos , Lobelina/farmacología , Lobelina/uso terapéutico , Masculino , Agonistas Nicotínicos/farmacología , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Vesículas Sinápticas/metabolismo , Sinaptosomas/metabolismo
10.
Psychiatry Res ; 167(1-2): 151-60, 2009 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-19345420

RESUMEN

One of the central problems in posttraumatic stress disorder (PTSD) is the inability to suppress fear even under safe conditions. The neural underpinnings of fear are clinically relevant but poorly understood. This study assessed fear potentiation and fear inhibition using fear-potentiated startle in a conditional discrimination procedure (AX+/BX-). We hypothesized that patients with PTSD would show normal fear potentiation and impaired fear inhibition. Subjects comprised 28 healthy volunteers and 27 PTSD patients (14 with low current symptoms, 13 with high current symptoms) who were presented with one set of colored lights (AX trials) paired with aversive air blasts to the throat, and a different series of lights (BX trials) presented without air blasts. We then presented A and B together (AB trials) to see whether B would inhibit fear potentiation to A. All groups showed robust fear potentiation in that they had significantly greater startle magnitude on AX trials than on noise-alone trials. However, the high-symptom PTSD group did not show fear inhibition: these subjects had significantly greater fear potentiation on the AB trials than both the controls and the low-symptom PTSD patients.


Asunto(s)
Miedo/fisiología , Inhibición Psicológica , Reflejo de Sobresalto/fisiología , Trastornos por Estrés Postraumático/diagnóstico , Estimulación Acústica , Percepción de Color/fisiología , Condicionamiento Clásico/fisiología , Discriminación en Psicología/fisiología , Electromiografía , Respuesta Galvánica de la Piel/fisiología , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Índice de Severidad de la Enfermedad , Trastornos por Estrés Postraumático/fisiopatología
11.
Int J Psychophysiol ; 71(3): 264-8, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19013485

RESUMEN

Posttraumatic stress disorder (PTSD) is a prolonged reaction to an extremely traumatic experience. One of the core symptoms of PTSD is hyper-arousal which can be the result of an elevated activation of the autonomic nervous system. Including psychophysiological assessment methods in PTSD research can point to the neurobiological bases of the disorder. The studies of psychophysiology of PTSD to date have mostly measured reactivity. The aim of the current study was to compare resting state psychophysiology and startle reflexes in PTSD patients and controls in a sample of Croatian combat veterans. We measured heart-rate, respiratory sinus arrhythmia, skin conductance, and eyeblink muscle contraction during an acclimation period and during the presentation of startle stimuli in 45 male PTSD patients and 33 male healthy controls. We found that PTSD patient had elevated baseline heart-rate and decreased respiratory sinus arrhythmia compared to the controls. Furthermore, PTSD patients had impaired habituation to the startle probe, but there was no group difference in initial startle magnitude. There was also no group difference in skin conductance level or skin conductance response. Startle habituation and baseline heart-rate appear to offer the most reliable psychophysiological indices of PTSD. This finding replicates trends in the literature in a new population of PTSD patients.


Asunto(s)
Trastornos de Combate/fisiopatología , Trastornos de Combate/psicología , Reflejo de Sobresalto/fisiología , Descanso/fisiología , Trastornos por Estrés Postraumático/fisiopatología , Trastornos por Estrés Postraumático/psicología , Guerra , Estimulación Acústica , Adulto , Análisis de Varianza , Arritmia Sinusal/etiología , Croacia , Electrocardiografía , Electromiografía , Respuesta Galvánica de la Piel/fisiología , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Psicofisiología , Tiempo de Reacción/fisiología , Veteranos
12.
Behav Neurosci ; 122(5): 1016-30, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18823159

RESUMEN

Fear extinction is a reduction in conditioned fear following repeated exposure to the feared cue in the absence of any aversive event. Extinguished fear often reappears after extinction through spontaneous recovery. Animal studies suggest that spontaneous recovery can be abolished if extinction occurs within minutes of acquisition. However, a limited number of human extinction studies have shown that short interval extinction does not prevent the return of fear. For this reason, we performed an in-depth parametric analysis of human fear extinction using fear-potentiated startle. Using separate single-cue and differential conditioning paradigms, participants were fear conditioned and then underwent extinction either 10 min (Immediate) or 72 hr (Delayed) later. Testing for spontaneous recovery occurred 96 hr after acquisition. In the single cue paradigm, the Immediate and Delayed groups exhibited differences in context, but not fear, conditioning. With differential conditioning, there were no differences in context conditioning and the Immediate group displayed less spontaneous recovery. Thus, the results remain inconclusive regarding spontaneous recovery and the timing of extinction and are discussed in terms of performing translational studies of fear in humans.


Asunto(s)
Reacción de Prevención/fisiología , Condicionamiento Clásico/fisiología , Extinción Psicológica/fisiología , Miedo/psicología , Reflejo de Sobresalto/fisiología , Estimulación Acústica/efectos adversos , Adolescente , Adulto , Análisis de Varianza , Señales (Psicología) , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tiempo de Reacción/fisiología , Factores de Tiempo
13.
Psychophysiology ; 45(5): 876-82, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18665868

RESUMEN

The acoustic startle reflex and its modulation by a prepulse are psychophysiological phenomena that are commonly studied to evaluate various aspects of information processing. Recent reports in human populations suggest that subjects from disparate racial backgrounds may have significant differences in the startle response. To determine if this pattern could be observed in our subject population and whether it extended to prepulse inhibition (PPI), we evaluated baseline startle parameters and PPI in 53 African-Americans (AA) and 38 European-Americans (EA). In AA compared to EA, mean startle magnitude and probability of blink response were lower, with no difference in habituation. PPI was greater in AA than EA when groups were matched on baseline startle magnitude. These findings support the idea of racial differences in startle response. Implications for study design are highlighted, and possible environmental and genetic influences are considered.


Asunto(s)
Etnicidad/psicología , Reflejo de Sobresalto/fisiología , Estimulación Acústica , Adulto , Negro o Afroamericano , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Población Blanca
14.
Behav Neurosci ; 120(5): 995-1004, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17014251

RESUMEN

Fear-potentiated startle is defined as an increase in the magnitude of the startle reflex in the presence of a stimulus that was previously paired with an aversive event. It has been proposed that a subject's awareness of the contingencies in the experiment may affect fear-potentiated startle. The authors adapted a conditional discrimination procedure (AX+/BX-), previously validated in animals, to a human fear-potentiated startle paradigm in 50 healthy volunteers. This paradigm allows for an assessment of fear-potentiated startle during threat conditions as well as inhibition of fear-potentiated startle during safety conditions. A response keypad was used to assess contingency awareness on a trial-by-trial basis. Both aware and unaware subjects showed fear-potentiated startle. However, awareness was related to stimulus discrimination and fear inhibition.


Asunto(s)
Aprendizaje por Asociación , Concienciación , Parpadeo , Condicionamiento Clásico , Miedo , Inhibición Psicológica , Reflejo de Sobresalto , Estimulación Acústica , Adulto , Anciano , Nivel de Alerta , Atención , Señales (Psicología) , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Desempeño Psicomotor
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