Differential effects of 5-HTTLPR genotypes on the behavioral and neural responses to tryptophan depletion in patients with major depression and controls

CONTEXT: Tryptophan depletion (TD) is a model used to study the contribution of reduced serotonin transmission to the pathogenesis of major depressive disorder (MDD). Recent studies have not sufficiently addressed the relative contribution of a functional-length triallelic polymorphism in the promoter of the serotonin transporter, 5-HTTLPR, to the behavioral and neural responses to TD in individuals with remitted MDD (rMDD) and controls. OBJECTIVE: To determine the role of 5-HTTLPR on the behavioral and neural responses to TD in medication-free patients with rMDD and individually matched controls. DESIGN: Participants were stratified according to diagnosis and 5-HTTLPR genotypes and underwent TD on one test day and sham depletion on the other test day in a prospective, double-blind, randomized order. SETTING: Outpatient clinic. PARTICIPANTS: Twenty-seven medication-free patients with rMDD (18 women and 9 men) and 26 controls (17 women and 9 men). INTERVENTIONS: Tryptophan depletion was induced by administration of capsules containing an amino acid mixture without tryptophan. Sham depletion used identical capsules containing lactose. Fludeoxyglucose F 18 positron emission tomography was performed 6 hours after TD. Magnetic resonance images were obtained for each participant. MAIN OUTCOME MEASURES: Quantitative positron emission tomography of regional cerebral metabolic rates for glucose and measures of depression using the Hamilton Depression Rating Scale. RESULTS: Behavioral responses to TD are affected by 5-HTTLPR in patients with rMDD and controls. A direct effect of 5-HTTLPR on the regulation of regional cerebral metabolic rates for glucose was identified in patients with rMDD for the amygdala, hippocampus, and subgenual anterior cingulate cortex. CONCLUSIONS: Variations in 5-HTTLPR modulate the sensitivity of patients with rMDD and controls to the behavioral effects of TD. In patients with rMDD, variations in triallelic 5-HTTLPR have a direct effect on regulation of regional cerebral metabolic rates for glucose in a corticolimbic circuit that has been implicated in rMDD.     

重性抑郁障碍临床痊愈患者心理社会功能特征研究

目的:研究重性抑郁障碍患者在达到临床痊愈标准后心理社会功能的特点。方法:采用生活质量综合评定问卷(GQOLI-74)的躯体、心理、社会功能分量表、17项汉密顿抑郁量表(HAMD)、社会支持评定量表(SSS)和生活事件量表(LES),对32例经住院治疗后达到临床痊愈的重性抑郁障碍患者和32名正常人进行调查分析。结果:协变量方差分析显示,以客观社会支持或负性生活事件为协变量时;研究组躯体功能维度(F=5.75,P<0.05)及躯体不适感因子得分(F=5.51,P<0.05)显著低于对照组;研究组心理功能维度中的正性情感因子得分(F=4.75,P<0.05)显著高于对照组;研究组社会功能维度中的工作学习(t=-3.80,P<0.01)和婚姻家庭因子得分(t=-3.30,P<0.01)显著低于对照组,该维度中的社会支持因子(F=4.94,P<0.05)和业余娱乐生活因子得分(F=9.30,P<0.01)显著高于对照组;研究组总体生活质量因子得分(F=4.14,P<0.05)显著低于对照组。结论:临床痊愈的重性抑郁障碍患者心理功能可能已恢复至正常水平,躯体、社会功能可能尚未完全恢复。     

Effects of tryptophan depletion on serum levels of brain-derived neurotrophic factor in unmedicated patients with remitted depression and healthy subjects

OBJECTIVE: Data suggest the involvement of serotonergic and neurotrophic systems in major depressive disorder. To investigate their potential interaction, the authors studied changes in serum levels of brain-derived neurotrophic factor (BDNF) during tryptophan depletion and sham depletion in unmedicated patients with remitted major depressive disorder and in a group of healthy comparison subjects. METHOD: Twenty-seven patients with remitted major depressive disorder and 20 healthy subjects underwent tryptophan depletion and sham depletion in a randomized, placebo-controlled, double-blind crossover study. Serum BDNF concentrations and plasma tryptophan concentrations as well as behavioral assessments were obtained. RESULTS: During tryptophan depletion, BDNF levels increased in healthy volunteers. By contrast, patients with remitted major depressive disorder were unable to mount this presumed compensatory response, and BDNF levels remained low in these patients. CONCLUSIONS: The results further substantiate the potential role of BDNF in major depressive disorder.     

Neurocognitive impairments and quality of life in unemployed patients with remitted major depressive disorder

Quality of life (QOL) has been reported to be impaired in patients with major depressive disorder (MDD), even after remission according to symptom rating scales. Although a relationship between QOL and neurocognitive dysfunction has been reported during depressive episodes, little is known about this relationship in remitted MDD patients. The aim of the present study was to investigate the relationship between QOL and neurocognitive dysfunction in patients with remitted MDD while controlling for confounding factors. Forty-three remitted MDD patients were assessed with neuropsychological tests and QOL, which was measured by a short-form 36-item health survey. The neurocognitive performances of the patients were compared with those of 43 healthy controls. We next evaluated the relationships between neurocognitive impairments, clinical factors, and QOL. Remitted MDD patients had poorer neurocognitive performances than healthy controls for psychomotor speed, attention, and verbal memory. Residual depressive symptoms were strongly associated with QOL. Delayed verbal recall was associated with general health perceptions, which are part of the QOL assessment, even after the effects of the residual depressive symptoms were considered. The results may indicate that clinicians should try to detect neurocognitive dysfunctions that may interfere with QOL using neurocognitive assessments in their daily practice.     

Neural indicators of emotion regulation via acceptance vs reappraisal in remitted major depressive disorder

Mood disorders are characterized by impaired emotion regulation abilities, reflected in alterations in frontolimbic brain functioning during regulation. However, little is known about differences in brain function when comparing regulatory strategies. Reappraisal and emotional acceptance are effective in downregulating negative affect, and are components of effective depression psychotherapies. Investigating neural mechanisms of reappraisal vs emotional acceptance in remitted major depressive disorder (rMDD) may yield novel mechanistic insights into depression risk and prevention. Thirty-seven individuals (18 rMDD, 19 controls) were assessed during a functional magnetic resonance imaging task requiring reappraisal, emotional acceptance or no explicit regulation while viewing sad images. Lower negative affect was reported following reappraisal than acceptance, and was lower following acceptance than no explicit regulation. In controls, the acceptance > reappraisal contrast revealed greater activation in left insular cortex and right prefrontal gyrus, and less activation in several other prefrontal regions. Compared with controls, the rMDD group had greater paracingulate and right midfrontal gyrus (BA 8) activation during reappraisal relative to acceptance. Compared with reappraisal, acceptance is associated with activation in regions linked to somatic and emotion awareness, although this activation is associated with less reduction in negative affect. Additionally, a history of MDD moderated these effects.     

CSF-hypocretin-1 levels in patients with major depressive disorder compared to healthy controls

Depressive patients exhibit symptoms of impaired regulation of wakefulness with hyperarousal and agitation as well as difficulties to falling asleep and preserving sleep continuity. Changes in hypocretin (hcrt) levels as polypeptides with impact on arousal and sleep-wake-regulation have been discussed in affective disorders but have not been investigated in patients with solely unipolar depression in comparison to healthy controls. In the present study, cerebrospinal fluid (CSF) levels of hcrt-1 for the first time were analyzed in patients with major depressive disorder (MDD) without psychiatric comorbidities and compared with levels in healthy controls. In 17 inpatients with MDD (mean Hamilton Depression Rating Scale 13.9 ± 7.4) and 10 healthy controls, CSF-hcrt-1 levels were measured using a fluorescence immunoassay (FIA). The mean hcrt-1 CSF levels in patients with MDD (74.3 ± 17.8pg/ml) did not differ compared to that of healthy controls (82.8 ± 22.1pg/ml). Hcrt-1 levels did not correlate with the severity of depressive episode, the symptoms of depression or the number of episodes. Although autonomic and neurohumoral signs of hyperarousal are common in MDD, hcrt-1 levels in CSF were not found to be altered in MDD compared to healthy controls. Whether hcrt-1 levels are altered in depressive patients exhibiting impaired vigilance regulation has to be investigated in further studies combining measures of CSF-hcrt-1 with electroencephalography.     

Differential responses to anxiogenic challenge studies in patients with major depressive disorder and panic disorder

Anxiogenic challenge studies (intravenous lactate infusion and oral fenfluramine challenge) were conducted in 17 patients with panic disorder (PD), 12 patients with major depressive disorder and a history of panic attacks (MDD-PD), 27 patients with major depression and no history of panic (MDD), and 12 normal controls. PD and MDD-PD patients revealed significantly greater anxiogenic responses to lactate infusion and fenfluramine administration than either MDD patients or controls. PD patients revealed the most robust anxiogenic responses to both challenges as well as associated significant prolactin and cortisol responses to fenfluramine. The findings suggest that the predisposition to panic attacks as seen in PD and MDD-PD patients may represent a distinct neurobiological diathesis which may coexist with a major depressive diathesis in some patients. The delineation of subgroups within the more heterogenous groups of patients with MDD and/or PD will lead to greater precision in the development of clinical treatment strategies. Thus, MDD-PD patients (better called panic-depressives) may have a more severe illness than patients with MDD alone which must be accounted for in the course of pharmacotherapy and psychotherapy.     

Mood-congruent bias in affective go/no-go performance of unmedicated patients with major depressive disorder

OBJECTIVE: Neuropsychological studies of major depressive disorder have described attentional biases for affectively laden stimuli, but these reports were based on measures obtained from medicated subjects. This study investigated performance of unmedicated depressed patients on the Affective Go/No-Go Task. METHOD: Twenty depressed patients and 20 healthy comparison subjects, matched for age, gender, and IQ, performed the Affective Go/No-Go Task as well as tests of attention and memory for nonaffective stimuli. RESULTS: Depressed patients did not differ from healthy subjects on memory task performance, but they made more omission errors on the attention task. On the Affective Go/No-Go Task, depressed patients made more omission errors during happy than sad word blocks and required more time to respond to happy than to sad words. In contrast, healthy subjects required more time to respond to sad than to happy words. CONCLUSIONS: Unmedicated depressed patients do not show a pattern of generalized cognitive impairment but, rather, specifically display an attentional deficit and a mood-congruent bias toward salient stimuli.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

目的 探讨抑郁症患者对情感刺激的行为学反应模式及其相关的杏仁核时程反应过程.方法 12例首次发病、未经治疗的抑郁症患者(抑郁症组)和13名健康个体(健康对照组)对观看正性、中性和负性情绪图片的愉悦度等评分;并在被动注视任务下行功能磁共振成像,采用感兴趣区分析方法,比较两组杏仁核在不同情绪图片任务组块间的血氧水平依赖(BOLD)信号时间反应特征.结果 (1)抑郁症组情绪图片愉悦度评分[正性:(6.6 ±0.2)分;中性:(4.7 ±0.1)分]低于健康对照组[分别为(7.7 ±0.2)分和(5.1 ±0.1)分],负性情绪图片评分[(3.4 ±0.3)分]高于健康对照组[(2.2 ±0.2)分;P<0.01].(2)对正性情绪图片任务,两组间右侧杏仁核存在"组×时间"交互作用(P=0.002);抑郁症组杏仁核BOLD信号变化率为(0.02±0.09)%,激活时间后移至Block 2.对负性情绪图片任务,两组间左侧杏仁核有"组×时间"交互作用(P=0.008),右侧杏仁核存在组主效应(P=0.007)和时间主效应(P=0.016),抑郁症组BOLD信号变化率低于(-0.06 ±0.14)%.结论 杏仁核是抑郁症患者丧失愉悦体验和情绪低落的神经基础之一.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

Altered ability to access a clinically relevant control network in patients remitted from major depressive disorder

Neurobiological models to explain vulnerability of major depressive disorder (MDD) are scarce and previous functional magnetic resonance imaging studies mostly examined “static” functional connectivity (FC). Knowing that FC constantly evolves over time, it becomes important to assess how FC dynamically differs in remitted‐MDD patients vulnerable for new depressive episodes. Using a recently developed method to examine dynamic FC, we characterized re‐emerging FC states during rest in 51 antidepressant‐free MDD patients at high risk of recurrence (≥2 previous episodes), and 35 healthy controls. We examined differences in occurrence, duration, and switching profiles of FC states after neutral and sad mood induction. Remitted MDD patients showed a decreased probability of an FC state (p < 0.005) consisting of an extensive network connecting frontal areas—important for cognitive control—with default mode network, striatum, and salience areas, involved in emotional and self‐referential processing. Even when this FC state was observed in patients, it lasted shorter (p < 0.005) and was less likely to switch to a smaller prefrontal–striatum network (p < 0.005). Differences between patients and controls decreased after sad mood induction. Further, the duration of this FC state increased in remitted patients after sad mood induction but not in controls (p < 0.05). Our findings suggest reduced ability of remitted‐MDD patients, in neutral mood, to access a clinically relevant control network involved in the interplay between externally and internally oriented attention. When recovering from sad mood, remitted recurrent MDD appears to employ a compensatory mechanism to access this FC state. This study provides a novel neurobiological profile of MDD vulnerability.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.     

抑郁症患者情绪图片反应特征及杏仁核反应模式的研究

Objective To explore the behavioral and related amygdaiar temporal response to emotional pictures in individuals with major depressive disorder(MDD).Methods Functional magnetic resonance imaging(fMRI)was adopted to examine the neural substrates of emotional pictures processing in 12 first-episode unmedicated MDD subjects(MDD)and 13 healthy controls(HC).Analyses were focused on the temporal dynamics of the blood-oxygen level dependant(BOLD)signal change in the amygdala across blocks of positive,neutral and negative emotional pictures.The crude score to emotional pictures was also recorded.Results(1)The crude score wag(6.6 ±0.2)to positive pictures and(4.7 ±0.1)to neutral pictures in depressed subjects,lower than that in HC(P＜0.01),and(3.4 ±0.3)to negativc pictures in depressed subjects,which was higher than that in HC(2.2±0.2,P＜0.01).(2)The bilateral amygdala showed attenuated and delayed response to the positive pictures.in which the right amygdala showed"group×time"interaction effect to positive pictures(P=0.002).For the negative pictures,there was"group×time"interaction effect in the left amygdala(P=0.008)and group main effect in the right amygdaia(P=0.007),with the attenuated BOLD signal change in MDD group.Conclusions It suggests that amygdala is one of the key neural substrates to the character of the depressed mood or loss of interest in individuals with MDD.Depressed subiects show the attenuated and blunted behavioral and amygdala response to emotional stimuli,which support the hypothesis of the unspecially blunted emotional response in major depressive disorder.