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Childhood maltreatment (CM) plays an important role in the development of major depressive disorder (MDD). The aim of this study was to examine whether CM severity and type are associated with MDD-related brain alterations, and how they interact with sex and age.
Within the ENIGMA-MDD network, severity and subtypes of CM using the Childhood Trauma Questionnaire were assessed and structural magnetic resonance imaging data from patients with MDD and healthy controls were analyzed in a mega-analysis comprising a total of 3872 participants aged between 13 and 89 years. Cortical thickness and surface area were extracted at each site using FreeSurfer.
CM severity was associated with reduced cortical thickness in the banks of the superior temporal sulcus and supramarginal gyrus as well as with reduced surface area of the middle temporal lobe. Participants reporting both childhood neglect and abuse had a lower cortical thickness in the inferior parietal lobe, middle temporal lobe, and precuneus compared to participants not exposed to CM. In males only, regardless of diagnosis, CM severity was associated with higher cortical thickness of the rostral anterior cingulate cortex. Finally, a significant interaction between CM and age in predicting thickness was seen across several prefrontal, temporal, and temporo-parietal regions.
Severity and type of CM may impact cortical thickness and surface area. Importantly, CM may influence age-dependent brain maturation, particularly in regions related to the default mode network, perception, and theory of mind.
Between 30 and 60% of adults with unipolar or bipolar disorders exhibit
impairments across multiple domains. However, little is known about
impaired functioning in youth with mood disorders.
To examine the prevalence of objective, subjective and observer-rated
disability in a large, representative sample of young people with a
primary mood disorder.
Individuals aged 16–25 years presenting to youth mental health services
for the first time with a primary mood disorder participated in a
systematic diagnostic and clinical assessment. Impairment was assessed
using objective (unemployment or disability payments), observer- (Social
and Occupational Functioning Assessment Scale; SOFAS) and self-rated
measures (role functioning according to the Brief Disability
Of 1241 participants (83% unipolar; 56% female), at least 30% were
functionally impaired on the objective, self-rated and/or observer-rated
measures, with 16% impaired according to all three criteria. Even when
current distress levels were taken into account, daily use of cannabis
and/or nicotine were significantly associated with impairment, with odds
ratios (OR) ranging from about 1.5 to 3.0. Comorbid anxiety disorders
were related to lower SOFAS scores (OR = 2–5).
Levels of disability were significant, even in those presenting for
mental healthcare for the first time. Functional impairment did not
differ between unipolar and bipolar cases, but some evidence suggested
that females with bipolar disorder were particularly disabled. The
prevalence of comorbid disorders (50%) and polysubstance use (28%) and
their association with disability indicate that more meaningful
indicators of mood episode outcomes should focus on functional rather
than symptom-specific measures. The association between functioning and
nicotine use requires further exploration.
Individuals with traumatic brain injury (TBI) often suffer from a number of enduring cognitive impairments such as in attention, memory, speed of processing information and dual-task performance.
The aim of this study was to assess the patterns of regional brain activation in response to the Tower of London (ToL) task in a group of patients suffering from chronic TBI using functional magnetic resonance imaging (fMRI).
fMRI was performed during performance of the ToL planning task in 10 patients suffering from severe TBI and in 10 age- and sex-matched controls using a 3 T magnetic resonance scanner.
Performance data showed no difference in response accuracy between the TBI group and the healthy control group. Statistical parametric brain maps showed that the TBI group activates larger and additional areas of the cerebral cortex than the healthy control group both for tasks and for a subtraction contrast between the tasks.
The results of this study are interpreted as a cortical reorganization inside the executive system of vigilance and working memory in patients with TBI. Both parietal and frontal areas are recruited to compensate for damaged brain tissue.
The electroencephalogram (EEG) can be a useful tool in determining differences in general neural activity and specific waveforms in individuals with a number of psychiatric disorders. This paper aims to outline and discuss significant findings in EEG and event-related potential (ERP) research into bipolar disorder (BD).
A literature review was performed through searches of MedLine, EMBASE, CINAHL and PsycInfo medical research databases for papers published from 1985 onwards. References of selected articles were also examined for other relevant studies.
Differences in general EEG data were found in subjects with BD, namely increased theta and delta and decreased alpha wave bands. Changes in EEG were also found in euthymic BD subjects and those undergoing medication programmes. ERP studies commonly report prolonged latencies and reduced amplitudes in the P300 component. Hyperfunctioning of the right hemisphere in BD was also reported in some studies, although further confirmation of this finding is required. Finally, the effects of medication and the role that genetics plays in EEG still remain unclear.
The literature reviewed demonstrates supporting evidence for the presence of significant differences in EEG and ERP data in subjects with BD. However, methodological considerations such as varying mood states and medication status of the patients need to be followed more stringently for future research to bring about a robust model of the cognitive deficits of BD.
Functional transcranial Doppler (fTCD) sonography provides a high temporal resolution measure of blood flow and has over the years proved to be a valuable tool in the clinical evaluation of patients with cerebrovascular disorders. More recently, due to advances in physics and computing, it has become possible to derive indices of cerebrovascular autoregulation (CA) as well as cerebrovascular pressure reactivity (CR), using non-invasive techniques. These indices provide a dynamic representation of the brain's regulatory blood flow mechanisms not only in pathological states but also in health. However, whilst the temporal resolution of these regulatory indices is very good, spatially, the localization of brain regions remains very poor, thus limiting its brain mapping capacity. Functional MRI, on the contrary, is a brain-imaging technique that operates on similar blood flow principles; however, unlike fTCD, it provides high spatial resolution. Because both fTCD and fMRI determine blood flow-dependant imaging parameters, the coupling of fTCD with fMRI may provide greater insight into brain function by virtue of the combined enhanced temporal and spatial resolution that each technique affords. This review summarizes the fTCD technique with particular emphasis on the CA and CR indices and their relationship in traumatic brain injury as well as in health.
The orienting reflex (OR) is a fundamental biological mechanism thought to reflect automatic adaptive processing of environmental stimuli necessary for successful interaction with the environment. It has been hypothesized that the OR is generated in response to novelty such as in the case where a mismatch results between an internal neuronal template stored in working memory and incoming stimuli. Recent blood oxygenated level dependant (BOLD) activation studies that have investigated networks involved in the processing of novelty have suggested the recruitment of a distributed limbic-neocortical network. In the present study, event-related functional resonance imaging with simultaneous autonomic electrodermal activity was used to detect single trials of an auditory oddball task associated with the OR.
The pattern of activations indicated two distinct, but partially overlapping, networks. Predominantly, frontal activations were seen for the target stimuli that did elicit an OR, including the orbitofrontal gyrus and anterior cingulate gyrus, as well as activations in the anterior thalamus and cerebellum. On contrary, parietal activations including the supramarginal gyrus and precuneus were seen for the target stimuli that that did not elicit an OR.