Anterior Hippocampal Volume Research Articles

Teaching an adult brain new tricks: A critical review of evidence for training-dependent structural plasticity in humans

A growing number of structural neuroimaging studies have reported significant changes in gray matter density or volume and white matter microstructure in the adult human brain following training. Such reports appear consistent with animal studies of training-dependent structural plasticity showing changes in, for example, dendritic spines. However, given the microscopic nature of these changes in animals and the relatively low spatial resolution of MRI, it is unclear that such changes can be reliably detected in humans. Here, we critically evaluate the robustness of the current evidence in humans, focusing on the specificity, replicability, and the relationship of the reported changes with behavior. We find that limitations of experimental design, statistical methods, and methodological artifacts may underlie many of the reported effects, seriously undermining the evidence for training-dependent structural changes in adult humans. The most robust evidence, showing specificity of structural changes to training, task and brain region, shows changes in anterior hippocampal volume with exercise in elderly participants. We conclude that more compelling evidence and converging data from animal studies is required to substantiate structural changes in the adult human brain with training, especially in the neocortex.

Anatomical and functional correlates of human hippocampal volume asymmetry

Hemispheric asymmetry of the human hippocampus is well established, but poorly understood. We studied 110 healthy subjects with 3-Tesla MRI to explore the anatomical and functional correlates of the R>L volume asymmetry. We found that the asymmetry is limited to the anterior hippocampus (hemisphere×region interaction: F(1,109)=42.6, p<.001). Anterior hippocampal volume was correlated strongly with the volumes of all four cortical lobes. In contrast, posterior hippocampal volume was correlated strongly only with occipital lobe volume, moderately with the parietal and temporal lobe volumes and not with the frontal lobe volume. The degree of R>L anterior hippocampal volume asymmetry predicted performance on a measure of basic cognitive abilities. This provides evidence for regional specificity and functional implications of the well-known hemispheric asymmetry of hippocampal volume. We suggest that the developmental profile, genetic mechanisms and functional implications of R>L anterior hippocampal volume asymmetry in the human brain deserve further study.

Structural and functional plasticity of the hippocampal formation in professional dancers and slackliners

The acquisition of special skills can induce plastic changes in the human hippocampus, a finding demonstrated in expert navigators (Maguire et al. (2000) Proc Natl Acad Sci USA 97:4,398-403). Conversely, patients with acquired chronic bilateral vestibular loss develop atrophy of the hippocampus, which is associated with impaired spatial memory (Brandt et al. (2005) Brain 128:2,732-741). This suggests that spatial memory relies on vestibular input. In this study 21 professional dancers and slackliners were examined to assess whether balance training with extensive vestibulo-visual stimulation is associated with altered hippocampal formation volumes or spatial memory. Gray matter voxel-based morphometry showed smaller volumes in the anterior hippocampal formation and in parts of the parieto-insular vestibular cortex of the trained subjects but larger volumes in the posterior hippocampal formation and the lingual and fusiform gyri bilaterally. The local volumes in the right anterior hippocampal formation correlated negatively and those in the right posterior hippocampal formation positively with the amount of time spent training ballet/ice dancing or slacklining at the time of the study. There were no differences in general memory or in spatial memory as assessed by the virtual Morris water task. Trained subjects performed significantly better on a hippocampal formation-dependent task of nonspatial memory (transverse patterning). The smaller anterior hippocampal formation volumes of the trained subjects may be the result of a long-term suppression of destabilizing vestibular input. This is supported by the associated volume loss in the parieto-insular vestibular cortex. The larger volumes in the posterior hippocampal formation of the trained subjects might result from their increased utilization of visual cues for balance. This is supported by the concomitant larger volumes in visual areas like the lingual and fusiform gyri. Our findings indicate that there is a spatial separation of vestibular and visual processes in the human hippocampus.

Failure to demonstrate that memory improvement is due either to aerobic exercise or increased hippocampal volume

We read with interest the article in PNAS, “Exercise training increases size of hippocampus and improves memory” by Erickson et al. (1). It is a noteworthy finding that over a 1-y period anterior hippocampal volume increased by 2% in the aerobic exercise group, whereas it decreased by 1.4% in the stretching control group. However, contrary to both the title and abstract, there is virtually no evidence in this article that exercise improved memory. After 1 y there were no differences between the exercise and control groups. “Both groups showed improvements in memory, as demonstrated by significant increases in accuracy between the first and last testing sessions for the aerobic exercise [t(2,51) = 2.08; P 0.05). Furthermore, changes in BDNF were not associated with improvements in memory function for either group (r 0.20).” The authors then “reasoned that increased hippocampal volume after the exercise intervention should translate to improved memory function.” To support this hypothesis they correlated aerobic exercise group hippocampal volume increase and memory improvement and found statistically significant correlations, which are small. For left hippocampus r = 0.23 (P < 0.05), accounting for 5% variance, and for right hippocampus r = 0.29 (P < 0.02), accounting for 8% variance. They concluded that “this indicates that increases in hippocampal volume after 1 y of exercise augments memory function in late adulthood.” However, association cannot be assumed to indicate causality. Furthermore, it is clear that although the aerobic exercise group improved on the memory task, so did the stretching control group in whom hippocampal volume decreased, further undermining any assumed link between hippocampal volume and improved memory. However, just such a link was explicitly drawn in the abstract, which states “here we show, in a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory.” Unfortunately both the title and abstract are misleading and a major overstatement of the findings. A similar lack of precision in reporting is evident elsewhere in the research literature, making it difficult to evaluate what the real evidence is in relation to cognitive enhancement interventions and aging. This clouds the picture for the scientific community and is misleading for the general public. It behooves us all to ensure rigor in our scientific reporting.

Studying Brain &amp; Behavior in Schizophrenia: Multivariate Surface Analysis of Hippocampus

Studying Brain &amp; Behavior in Schizophrenia: Multivariate Surface Analysis of Hippocampus

Structural pathology underlying neuroendocrine dysfunction in schizophrenia

Polydipsic hyponatremic schizophrenic (PHS) patients exhibit altered neuroendocrine activity that has been linked to their life-threatening water imbalance, as well as to impaired function and reduced volume of the anterior hippocampus. Polydipsic patients without hyponatremia (polydipsic normonatremic schizophrenics: PNS) exhibit similar, albeit less marked, changes in neuroendocrine activity and anterior hippocampal function, but not reduced anterior hippocampal volume. Indeed, reduced anterior hippocampal volume is seen in patients with normal water balance (nonpolydipsic normonatremic schizophrenics: NNS) whose neuroendocrine activity and anterior hippocampal function differ markedly from those with polydipsia. In an effort to reconcile these findings we measured hippocampal, amygdala and 3rd ventricle shapes in 26 schizophrenic patients (10 PNS, 7 PHS, 9 NNS) and 12 healthy controls matched for age and gender. Bilateral inward deformations were localized to the anterior lateral hippocampal surface (part of a neurocircuit which modulates neuroendocrine responses to psychological stimuli) in PHS and to a lesser extent in PNS, while deformations in NNS were restricted to the medial surface. Proportional deformations of the right medial amygdala, a key segment of this neurocircuit, were seen in both polydipsic groups, and correlated with the volume of the 3rd ventricle, which lies adjacent to the neuroendocrine nuclei. Finally, these structural findings were most marked in those with impaired hippocampal-mediated stress responses. These results reconcile previously conflicting data, and support the view that anterior lateral hippocampal pathology disrupts neuroendocrine function in polydipsic patients with and without hyponatremia. The relationship of these findings to the underlying mental illness remains to be established.

Group differences in anterior hippocampal volume and in the retrieval of spatial and temporal context memory in healthy young versus older adults

The ability to retrieve temporal and spatial context information from memory declines with healthy aging. The hippocampus (HC) has been shown to be associated with successful encoding and retrieval of spatio-temporal context, versus item recognition information (Davachi, Mitchell, & Wagner, 2003; Nadel, Samsonovich, Ryan, & Moscovitch, 2000; Ross & Slotnick, 2008). Aging has been linked to volume reduction in the HC (Bouchard, Malykhin, Martin, Hanstock, Emery, Fisher, & Camicioli, 2008; Malykhin, Bouchard, Camicioli, & Coupland, 2008; Raz et al., 2005). As such, age-associated reductions in anterior HC volume may contribute to the context memory deficits observed in older adults. In the current MRI study we investigated whether item recognition, spatial context and temporal context memory performance would be predicted by regional volumes in HC head (HH), body (HB) and tail (HT) volumes, using within group multiple regression analyses in a sample of 19 healthy young (mean age 24.3) and 20 older adults (mean age 67.7). We further examined between age-group differences in the volumes of the same HC sub-regions. Multiple regression analyses revealed that in younger adults both spatial and temporal context retrieval performance was predicted by anterior HC volume. Older age was associated with significant volume reductions in HH and HB, but not HT; and with reduced ability to retrieve spatial and temporal contextual details from episodic memory. However, HC volumes did not predict context retrieval performance in older adults. We conclude that individual differences in anterior, not posterior, HC volumes predict context memory performance in young adults. With age there may be a posterior-to-anterior shift from using HC-related processes, due to HC volume loss, to employing the prefrontal cortex to aid in the performance of cognitively demanding context memory tasks. However, due to concomitant changes in the prefrontal system with age, there are limits to compensation in the aging brain.

Anterior hippocampal and orbitofrontal cortical structural brain abnormalities in association with cognitive deficits in schizophrenia

Objective Numerous studies have implicated the hippocampus and prefrontal cortex in schizophrenia. However, precisely which subregions of the hippocampus and prefrontal cortex are abnormal remain unknown. Our study goal was to investigate the structure of the anterior hippocampus, posterior hippocampus, dorsolateral prefrontal cortex (DLPFC), and orbitofrontal cortex (OFC) simultaneously in thirty-eight patients with schizophrenia and twenty-nine controls to determine which of these subregions are abnormal in schizophrenia. As an exploratory study goal, we investigated the relation of neurocognition to brain structure in schizophrenia patients. Method We generated detailed structural magnetic resonance imaging data and compared hippocampal and prefrontal subregional structural brain volumes between schizophrenia and control groups. We obtained a neurocognitive test battery in schizophrenia patients and studied the association of abnormal brain structures to neurocognition. Results Structural brain abnormalities were pinpointed to the left anterior hippocampus and left OFC in schizophrenia patients, which were both significantly reduced in volume. The DLPFC and posterior hippocampus, though numerically decreased in volume, were not significantly decreased. Anterior hippocampal volumes were more strongly associated with OFC volumes in schizophrenia patients compared to controls. By contrast, DLPFC volume was unrelated to anterior or posterior hippocampal volume. Both the anterior hippocampus and OFC were independently related to cognitive abnormalities common in schizophrenia, including indices of verbal, language, and executive functions. The DLPFC and posterior hippocampal volumes were unrelated to cognitive measures. Conclusions These findings highlight related abnormalities of the anterior hippocampus and OFC in schizophrenia, which may shed light on the pathophysiology of the disorder.

Anterior hippocampal volume is reduced in behaviorally depressed female cynomolgus macaques

Hippocampal (HC) function and morphology have been implicated in the pathophysiology of depression. Reduced HC volume has been observed in depressed humans, although the effect is not always significant. Studies of functional differentiation of the HC have revealed that the anterior portion is associated with emotional and anxiety-related functioning, and the posterior portion with memory processing. As such, measuring whole HC volume may mask differences seen only in the anterior or posterior HC. We used unbiased stereology to measure whole, anterior, and posterior HC volumes in 12 adult female cynomolgus macaques, half of which exhibited spontaneously occurring depressive behavior defined as a slumped/collapsed body posture with open eyes, and a relative lack of responsivity to environmental stimuli. The two groups were otherwise matched on circulating estradiol, progesterone, and cortisol levels, social status, estimated age, and body weight. Frozen postmortem HC tissue from depressed and nondepressed monkeys was serially sectioned and thionin-stained. According to established neuroanatomical guidelines and with the aid of Neurolucida software (MBF Bioscience), every 10th section throughout the extent of the HC was manually traced and used to reconstruct the 3D models used to determine volumes. Anterior and posterior HC were delineated by the presence or absence of the uncus. No significant differences were found between depressed and nondepressed monkeys for whole or posterior HC volume, although the average HC volume was 4% smaller in depressed than nondepressed monkeys. Anterior HC volumes were significantly smaller (15.4%) in depressed compared to nondepressed monkeys. These results indicate that reduced volume in the anterior HC, an area previously implicated in emotional functioning, may be associated with a depressive phenotype in female cynomolgus macaques.

Hippocampal Volumes in First-Episode Psychosis

Hippocampal Volumes in First-Episode Psychosis

Hippocampal Volumes in First-Episode Psychosis

Studies have shown that patients with schizophrenia have smaller hippocampi than healthy comparison subjects. There are, however, inconsistencies regarding the relationship between clinical characteristics and topographical differences in hippocampal volumetry. The authors investigated hippocampal volumes in minimally treated patients with first-episode schizophrenia spectrum disorders, relative to comparison subjects. Thirty-nine consecutive patients and 29 matched comparison subjects were scanned using 1.5 tesla MR system. Patients had significantly smaller right anterior, right, and anterior hippocampal volumes than comparison subjects. There was a gender by diagnosis effect: female patients showed significantly smaller anterior and right hippocampal volumes than female comparison subjects, an effect not seen in male patients. Our results suggest that smaller hippocampal volumes are present even in early stages of the illness.

Neuropsychological impairment in patients with schizophrenia and evidence of hyponatremia and polydipsia.

Patients with schizophrenia and water imbalance may represent a subset of patients with distinct pathophysiological abnormalities and susceptibility to cognitive impairment. Specifically, patients with polydipsia and hyponatremia have been shown to have smaller anterior hippocampal volumes, which are also associated with various impairments in neuroendocrine function. To determine whether abnormalities in patients with water imbalance extend to the cognitive realm, the present study evaluated neuropsychological functioning in three groups of patients with schizophrenia: polydipsic hyponatremic, polydipsic normonatremic, and nonpolydipsic normonatremic. Participants were administered cognitive tests assessing intelligence, attention, learning/memory (verbal, nonverbal, emotional), and facial discrimination. Hyponatremic patients showed poorer overall neuropsychological functioning relative to all other patients, and polydipsic normonatremic patients performed intermediate to the other two groups. Results indicate that patients with schizophrenia and polydipsia, and particularly those with hyponatremia, show prominent cognitive deficits relative to patients without water imbalance. The clinical, neuroendocrine, and cognitive abnormalities in these patients may arise from pathology within the anterior hippocampus and associated prefrontal/limbic brain regions.

Schizophrenia diagnosis and anterior hippocampal volume make separate contributions to sensory gating

Impaired P50 gating is thought to reflect a core deficit in schizophrenia, but the relevant neural network is not well understood. The present study used EEG and MEG to assess sensory gating and volumetric MRI to measure hippocampal volume to investigate relationships between them in 22 normal controls and 22 patients with schizophrenia. In the schizophrenia group, anterior but not posterior hippocampal volume was smaller, and both the P50 and M50 gating ratios were larger (worse) than in controls. Independent of group, left-hemisphere M50 gating ratio correlated negatively with left anterior hippocampal volume, and right-hemisphere M50 gating ratio correlated negatively with right anterior hippocampal volume. Schizophrenia diagnosis predicted M50 gating independent of hippocampal volume. These results are consistent with the finding that hippocampus is a critical part of a fronto-temporal circuit involved in auditory gating.

Genetic influences on hippocampal structure and function in recombinant inbred mice

Previously, we identified separate genetic influences on ventral versus dorsal hippocampal volume in BXD recombinant inbred mice [Martin MV, Dong HX, Vallera D, Lu L, Williams RW, Rosen GD, et al. Independent quantitative trait loci influence ventral and dorsal hippocampal volume in recombinant inbred strains of mice. Genes Brain Behav 2006;5:614–23]. Based on genotype at genetic markers associated with ventral hippocampal volume, we evaluated BXD mouse strains with relatively small versus large ventral hippocampal volumes using numerous behavioral paradigms known to rely upon hippocampal function and several other tasks that tap into behaviors analogous to those often impaired in schizophrenia. We observed a relationship between genotype at markers known to influence ventral hippocampal volume and working memory at an intermediate memory load. There was no association between genotype at markers known to influence ventral hippocampal volume and spatial reference memory, prepulse inhibition, or elevated plus maze performance. The relevance of these findings for understanding the pathophysiology of schizophrenia are discussed, including the possibility that genetic predisposition toward anterior hippocampal volume reductions and working memory deficits in schizophrenia may be related through a shared genetic locus.

Aging hippocampus and amygdala

Earlier studies suggest that the anterior hippocampus may show resilience to age-associated volume loss. This study compared high-resolution magnetic resonance images obtained from younger (n=28; age range: 22-50 years) and older (n=39; age range: 65-84 years) healthy right-handed individuals to determine whether age-related volume changes varied between the hippocampal head, body and tail. Volumetric reductions were progressively more severe from hippocampal head to tail. Amygdala volume differences were intermediate in size. Although limited by the cross-sectional design, these data suggest that hippocampal subregions show a gradient of volume reduction in healthy aging that contrasts with the preferential reduction of anterior hippocampal volumes in Alzheimer's and Parkinson's diseases.

Cortisol levels in relation to hippocampal sub-regions in subjects with first episode schizophrenia

The etiology of hippocampal volumetric reductions in schizophrenia is largely unknown. In addition to genetic factors, environmental factors might also play a role. High levels of glucocorticoids are known to affect hippocampal volume in disorders such as Cushing's syndrome, but the relationship between cortisol and hippocampal volumes has not been studied in schizophrenia. We obtained diurnal salivary cortisol levels and MRI images to explore the link between cortisol levels and regional hippocampal volumes in healthy controls (N=29) and subjects with first episode schizophrenia (N=16) at the time of first admission. T1-weighted coronal MR images (slice thickness=1.5 mm) were acquired through the whole head using a 3D Fast SPGR IR Prep sequence on a 1.5 T GE imaging system. Using ANOVA, cumulative daily cortisol exposure calculated as area under the curve for each subject revealed significantly higher cortisol levels in the patient group [F(1,43)=4.4 p=0.04]. However, there were no statistically significant associations between the cortisol measures and regional hippocampal volumes in the subjects, except a trend level link between anterior hippocampal volume and cortisol in the positive direction, in parallel to previous findings in healthy adolescents. Our findings do not suggest a robust association between cortisol levels and hippocampal volumes in a first episode schizophrenia sample. Larger scale studies are needed to conclude a link between the two measures, yet it is possible that the negative association that was previously shown in other disorders may not apply to schizophrenia.

Reduced anterior hippocampal formation volume in hyponatremic schizophrenic patients

Diminished hippocampal volume occurs in the anterior segment of some schizophrenic patients, and in the posterior segment in others. The significance of hippocampal pathology in general and these segmental differences in specific is not known. Several lines of evidence suggest anterior hippocampal pathology underlies the life-threatening hyponatremia seen in a subgroup of patients with schizophrenia; therefore our goal was to determine if this region was preferentially diminished in hyponatremic patients. We studied seven polydipsic hyponatremic, ten polydipsic normonatremic, and nine nonpolydipsic normonatremic schizophrenic inpatients, as well as 12 healthy controls. All underwent structural scanning on a high resolution (3.0 T) magnetic resonance imaging (MRI) scanner. Hippocampal formation, amygdala, and third ventricle volumes were manually traced in each subject. The hippocampus was divided at the posterior extent of the uncus, and all structural volumes were corrected for whole brain volume and other significant recognized factors (i.e., age, gender, height, parental education). Despite being overhydrated, anterior hippocampal formation volume was diminished in those with polydipsia and hyponatremia relative to each of the other three groups. Third ventricle volume was larger in this group than in healthy controls but similar to the two patient groups. Posterior hippocampal and amygdala volumes did not differ between groups. Other potential confounds (e.g., water imbalance) either had no effect or accentuated these differences. We conclude the anterior hippocampal formation is smaller in hyponatremic schizophrenic patients, thereby linking an important and objective clinical feature of schizophrenia to a neural pathway that can be investigated in animal models. The findings strengthen the hypothesis that anterior hippocampal formation pathology disrupts functional connectivity with other limbic structures in schizophrenia.

Hippocampal volume in childhood complex partial seizures

Purpose This study compared hippocampal volume in children with cryptogenic epilepsy, all of whom had complex partial seizures (CPS), and age and gender matched normal children controlling for between group differences in IQ and demographic variables (e.g., age, gender, ethnicity, socioeconomic status). It also examined the relationship between hippocampal volumes and seizure variables in the patients. Methods Using quantitative magnetic resonance imaging (MRI), we compared the hippocampal volumes of 19 medically treated children with CPS, aged 6–14 years, to 21 age and gender matched normal children. Results The children with CPS had significantly smaller total hippocampal volumes than the normal children. This finding was accounted for primarily by significantly smaller anterior hippocampal volumes. Within the CPS group, smaller total and posterior hippocampus volumes were significantly associated with longer duration of illness. Anterior hippocampal volumes, however, were unrelated to seizure variables. Conclusions These findings imply impaired development of the hippocampus, particularly the anterior hippocampus, and a differential effect of the underlying illness and on-going seizures on hippocampal development in medically controlled pediatric CPS.

Hippocampus, VI: Depression and the Hippocampus

Back to table of contents Previous article Next article Images in NeuroscienceFull AccessHippocampus, VI: Depression and the HippocampusAlexander Neumeister, M.D., , Dennis S. Charney, M.D., , and Wayne C. Drevets, M.D., Alexander NeumeisterSearch for more papers by this author, M.D., West Haven, Ct., Dennis S. CharneySearch for more papers by this author, M.D., New York, N.Y., and Wayne C. DrevetsSearch for more papers by this author, M.D., Bethesda, Md.Published Online:1 Jun 2005https://doi.org/10.1176/appi.ajp.162.6.1057AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail Recent evidence suggests that the hippocampus may be disordered in patients with major depressive disorder, with the speculation that disease-associated elevated cortisol levels might mediate alterations in hippocampal physiology and, consequently, alter cognitive performance in persons with the illness. In support of this are reports from several laboratories that have shown a reduction in hippocampal volume in the illness that is most severe in those with early age at onset, many previous episodes, longer durations of untreated illness, and a childhood abuse history. It appears that the posterior segment of the hippocampus is most consistently involved in the volume reduction in patients with major depressive disorder. Cognitive studies show that learning and memory are altered in major depressive disorder, consistent with an abnormality in the posterior hippocampus. Cellular changes in the posterior hippocampus in patients with major depressive disorder have still to be elucidated, but there is evidence of an involvement of an alteration in the serotonin and neurotropin systems. Of interest is that a reduction of mRNA for the serotonin 5-HT1a receptor has been demonstrated in patients with major depressive disorder. It is not clear whether this represents a primary abnormality specific to depression or, alternatively, whether reduced 5-HT1a receptor expression results from abnormal interaction between neurotropins (such as brain-derived neurotrophic factor) and serotonin receptors. Illustrated here is an approach to analyzing volume in the human hippocampus. Using anatomically specific criteria, hippocampal regions of interest were defined on anterior to posterior structural MRI scans (Figure, left). We averaged the volumes for these hippocampal regions of interest across all medication-free depressed patients and contrasted these with matched normal comparison subjects. Consistent with previous data from medicated patients, hippocampal volumes were reduced in persons with major depressive disorder, and these reductions were restricted to the posterior regions (Figure, right). We speculate that this volume reduction represents cellular alterations in 5-HT1a and neurotropin mechanisms, possibly related to elevated cortisol levels.One might consider that these kinds of changes underlie the alterations in learning and memory associated with major depressive disorder.Address reprint requests to Dr. Tamminga, UT Southwestern Medical Center, Department of Psychiatry, 5323 Harry Hines Blvd., #NC5.914, Dallas, TX 75390-9070; [email protected] (e-mail). Figure. The four magnetic resonance images of the medial temporal cortex show the most anterior (a) to posterior (d) regions of interest, respectively, of the hippocampus. The graph shows the average total, posterior, and anterior hippocampal volumes for depressed versus normal subjects and shows the posterior volume reduction in those with major depressive disorder. FiguresReferencesCited byDetailsCited byReduced Sulcal Depth in Central Sulcus of Major Depressive DisorderExperimental Neurobiology, Vol. 31, No. 5Sex-specific hippocampus volume changes in obstructive sleep apneaNeuroImage: Clinical, Vol. 20BMC Psychiatry, Vol. 18, No. 1Investigative Magnetic Resonance Imaging, Vol. 19, No. 1, Vol. 209PLoS ONE, Vol. 7, No. 5Neurosurgery Clinics of North America, Vol. 22, No. 2Research in Developmental Disabilities, Vol. 32, No. 5Indo-Pacific Journal of Phenomenology, Vol. 10, No. 2Emotion Modelling Towards Affective Pathogenesis1 December 2009 | Australasian Psychiatry, Vol. 17, No. 6Beyond Neurobiological Reductionism14 August 2009 | Theory & Psychology, Vol. 19, No. 4Peripheral biomarker composite associated with smaller hippocampal volumeNeuroReport, Vol. 19, No. 13Functional Magnetic Resonance in PsychiatryTopics in Magnetic Resonance Imaging, Vol. 19, No. 2The role of hippocampus in the pathophysiology of bipolar disorderBehavioural Pharmacology, Vol. 18, No. 5-6Neuroimaging Clinics of North America, Vol. 17, No. 4Current Opinion in Psychiatry, Vol. 20, No. 1 Volume 162Issue 6 June 2005Pages 1057-1057 Metrics PDF download History Published online 1 June 2005 Published in print 1 June 2005

Reduced hippocampal volume in unmedicated, remitted patients with major depression versus control subjects

Hippocampal volumes obtained from a group of medication-free, remitted subjects with recurrent major depressive disorder (MDD) were compared against corresponding measures from healthy controls. Thirty-one subjects with recurrent MDD in full remission, and 57 healthy controls underwent high resolution magnetic resonance imaging (MRI) on a GE 3T scanner. Eight patients with MDD were medication-naive, and twenty-three MDD patients were off antidepressant medications for a mean of 30 months at the time of the MRI study. Patients showed smaller total and posterior hippocampal volume relative to controls. Anterior hippocampal volume did not differ between patients and controls. Recurrent depression is associated with smaller hippocampal volume which is most prominent in the posterior hippocampus. Smaller hippocampal volume appears to be a trait characteristic for MDD.