Brain Scans Differentiate Suicidal from Non-Suicidal Patients with Bipolar Disorder

September 29, 2017 · Posted in Brain Imaging · Comment 

brainPeople with bipolar disorder are at high risk for suicidal behavior beginning in adolescence and young adulthood. A 2017 study by Jennifer A. Y. Johnston and colleagues in the American Journal of Psychiatry uses several brain-scanning techniques to identify neurobiological features associated with suicidal behavior in people with bipolar disorder compared to people with bipolar disorder who have never attempted suicide. Clarifying which neural systems are involved in suicidal behavior may allow for better prevention efforts.

The study included 26 participants who had attempted suicide and 42 who had not. Johnston and colleagues used structural, diffusion tensor, and functional magnetic resonance imaging (MRI) techniques to identify differences in the brains of attempters and non-attempters.

Compared to those who had never attempted suicide, those who had exhibited reductions in gray matter volume in the orbitofrontal cortex, hippocampus, and cerebellum. They also had reduced white matter integrity in the uncinate fasciculus, ventral frontal, and right cerebellum regions. In addition, attempters had reduced functional connectivity between the amygdala and the left ventral and right rostral prefrontal cortex. Better right rostral prefrontal connectivity was associated with less suicidal ideation, while better connectivity of the left ventral prefrontal area was linked to less lethal suicide attempts.

Breathing in Through the Nose Enhances Judgment and Memory

August 28, 2017 · Posted in Brain Imaging · Comment 

breathing through the nose

A 2016 study published in the Journal of Neuroscience reported that the rhythm of breathing changes electrical activity in the brain and can improve emotional judgments and recall. Breathing in through the nose seemed to produce benefits compared to breathing out or to breathing in through the mouth.

Participants more easily identified a fearful face if they viewed it while breathing in. They also had an easier time remembering objects they observed while breathing in. The effects were not seen if the participants breathed through their mouth.

The researchers, led by Christina Zelano, reported that there was a major difference in brain activity in the amygdala and hippocampus during inhalation versus exhalation. Breathing in, in addition to stimulating the olfactory cortex responsible for smell perception, seems to activate the entire limbic system, the emotional center of the brain.

Brain Inflammation Found in Autopsy Studies of Teen and Adult Suicides

December 14, 2016 · Posted in Brain Imaging, Neurobiology · Comment 

brain inflammation

Suicide and depression have both been linked to elevated levels of inflammatory cytokines in the blood and cerebrospinal fluid. A recent study finds that these inflammatory markers are also elevated in the brains of teens and depressed adults who died from suicide.

In autopsy studies, researcher Ghanshyam N. Pandey measured levels of the inflammatory cytokines interleukin-1beta, interleukin 6, and TNF-alpha in the brains of teen suicide victims, and compared these to the brains of teens who died from other causes. Pandey also measured levels of interleukin-1beta, interleukin 6, interleukin 8, interleukin 10, interleukin 13, and TNF-alpha in the prefrontal cortex of depressed adult suicide victims and compared them to levels in adults who died of other causes.

There were abnormalities in the inflammatory markers in the brains of those who died from suicide compared to their matched controls. The suicide victims had higher levels of interleukin-1beta, interleukin 6, and TNF-alpha than the controls. Among the adults, levels of the anti-inflammatory cytokine interleukin 10 were low in the suicide victims while levels of Toll-like receptors (TLR3 and TLR4), which are involved in immune mechanisms, were high.

Brain inflammation has also been observed in positron emission tomography (PET) scans of depressed patients, where signs of microglial activation can be observed. Elevated inflammatory cytokines are also found in the blood of some people with bipolar disorder, depression, and schizophrenia.

Pandey presented this research at the 2016 meeting of the Society of Biological Psychiatry.

Cognitive Behavioral Therapy Improves Depression, PTSD by Improving Brain Connectivity

July 8, 2016 · Posted in Brain Imaging, Current Treatments · Comment 

cognitive behavioral therapy

A recent study clarified how cognitive behavioral therapy improves symptoms of depression and post-traumatic stress disorder (PTSD). The participants were 62 adult women. One group had depression, one had PTSD, and the third was made up of healthy volunteers. None were taking medication at the time of the study. The researchers, led by Yvette Shelive, used functional magnetic resonance imaging (fMRI) to analyze participants’ amygdala connectivity.

At the start of the study, participants with depression or PTSD showed diminished connectivity between the amygdala and brain areas related to cognitive control, the process by which the brain can vary behavior and how it processes information in the moment based on current goals. The lack of connectivity reflected the severity of the participants’ depression. Twelve weeks of cognitive behavioral therapy improved mood and connectivity between the amygdala and these control regions, including the dorsolateral prefrontal cortex and the inferior frontal cortex. These regions also allow for executive functioning, which includes planning, implementation, and focus.

Some Evidence of Brain Inflammation in Depression

June 22, 2016 · Posted in Brain Imaging · Comment 

brain inflammationMany studies have found links between levels of inflammatory molecules in the blood and depression or depressive symptoms. There has been less research about inflammation in the brain and its possible role in depressive illness. Improvements in positron emission topography (PET) scan technology now allow for better brain imaging that can reveal when microglia are activated. (Microglia serve as the main immune responders in the central nervous system.)

A study by researcher Jeffrey Meyer found evidence of microglial activation in several brain regions (including the prefrontal cortex, the anterior cingulate cortex, and the insula) in people in an episode of depression who were not receiving any treatments. Participants with more microglial activation in the anterior cingulate cortex and insula had more severe depression and lower body mass indexes.

Meyer, who presented this research at a scientific meeting in December, called it strong evidence for brain inflammation in depressive episodes, and suggested that treatments that target microglial activation would be promising for depression.

However, at the same meeting, researcher Erica Richards reported that she had not been able to replicate Meyer’s results. Her research, which included depressed participants both on and off medication and non-depressed participants, found that depressed participants did show more inflammation in the two brain regions she targeted, the anterior cingulate and the subgenual cortices, but this difference did not reach statistical significance, particularly when patients taking antidepressants were included in the calculations. Richards hopes that with a greater sample size, the data may show a significant difference in brain inflammation between depressed and non-depressed participants.

Poverty Early in Life Decreases White Matter Integrity in the Brain

May 11, 2016 · Posted in Brain Imaging, Neurobiology · Comment 

child poverty affects white matter in brain

One-fifth of children in America grow up in poor families. Poverty can affect development, health, and achievement, and new evidence shows it even affects brain structure.

New unpublished research suggests that early poverty can affect the brain’s structure into adulthood. At a 2015 scientific meeting, researcher James Swain reported that socio-economic status at age 9 was associated with the integrity of white matter in several regions of the brain, including the hippocampus, parahippocampal gyrus, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, corpus collosum, and thalamus at age 23–25, regardless of income at that time.

The brain regions affected by childhood poverty support executive function (planning and implementation skills), social cognition, memory, and language processing. White matter provides the physical connections between parts of the brain, so damage to white matter may lead to problems with functional connectivity of the brain.

Brain Inflammation in People at High Risk for Schizophrenia

January 20, 2016 · Posted in Brain Imaging, Risk Factors · Comment 
brain inflammation in schizophrenia

Microglial activity in the brains of people who are healthy, people at high risk for schizophrenia, and people who have been diagnosed with schizophrenia.

A 2016 study by Peter S. Bloomfield and colleagues in the American Journal of Psychiatry used PET scans to compare the activity of microglia, immune cells in the central nervous system, in healthy controls, people with schizophrenia, and those at high risk for the illness. It found that both people with schizophrenia and those at high risk had greater brain inflammation than the healthy controls.

The study was the first to show that microglial activity was elevated in people at high risk (who showed some preliminary symptoms of schizophrenia). The finding had a large effect size.

Microglial activity was also correlated with symptom severity in the high-risk participants. Increased microglial activity was not linked to depression, suggesting that it is specific to the development of psychosis.

These findings resemble those of other recent studies showing increased inflammation in people at high risk for psychosis.

The study suggests that increased microglial activity occurs before a first episode of psychosis. That means it could help identify people who may develop schizophrenia. The findings also suggest that anti-inflammatory treatment could theoretically be used to prevent psychosis.

RTMS for Depression Increases Volume of Specific Brain Regions

November 13, 2015 · Posted in Brain Imaging, Current Treatments · Comment 

rTMS

Repeated transcranial magnetic stimulation (rTMS) is a treatment for depression in which magnets placed near the skull stimulate electrical impulses in the brain. In a poster presented at the 2015 meeting of the Society of Biological Psychiatry, Martin Lan and colleagues presented results of the first study of structural changes in the brain following rTMS.

In the study, 27 patients in an episode of major depression underwent magnetic resonance brain scans before and after receiving rTMS treatment over their left prefrontal cortices. Lan and colleagues reported that several cortical regions related to cognitive appraisal, the subjective experience of emotion, and self-referential processing increased in volume following rTMS treatment: the anterior cingulate, the cingulate body, the precuneous, right insula, and gray matter in the medial frontal gyrus. The increases ranged from 5.3% to 15.7%, and no regions decreased in volume. More than 92% of the participants showed increased gray matter in all of these regions.

The brain changes were not correlated with antidepressant response to rTMS, but suggest a possible mechanism by which rTMS is effective in some people. Lan and colleagues concluded that rTMS likely had neuroplastic effects in areas of the brain that are important for emotion regulation.

Blood and Now Brain Inflammation Linked to Depression

September 16, 2015 · Posted in Brain Imaging, Risk Factors · Comment 

microgliaThere is growing evidence of a link between inflammation of depression. At the 2015 meeting of the Society of Biological Psychiatry, researcher Jeff Meyer summarized past studies on inflammatory markers. These are measurements, for example of certain proteins in the blood, that indicate the presence of inflammation in the body.

Common inflammatory markers that have been linked to depression include IL-6, TNF-alpha, and c-reactive protein. At the meeting, Meyer reviewed the findings on each of these. Twelve studies showed that IL-6 levels are elevated in the blood of patients with depression. Four studies had non-significant results of link between IL-6 and depression, and Meyer found no studies indicating that IL-6 levels were lower in those with depression. Similarly, for TNF-alpha, Meyer found 11 studies linking elevated TNF-alpha with depression, four with non-significant results, and none showing a negative relationship between TNF-alpha and depression. For c-reactive protein, six studies showed that c-reactive protein was elevated in people with depression, six had non-significant results, and none indicated that c-reactive protein was lower in depressed patients.

Most studies that have linked inflammation to depression have done so by measuring inflammatory markers in the blood. It is more difficult to measure inflammation in the brain of living people, but Meyer has taken advantage of new developments in positron emission tomography (PET) scans to measure translocator protein binding, which illustrates when microglia are activated. Microglial activation is a sign of inflammation. Translocator protein binding was elevated by about 30% in the prefrontal cortex, anterior cingulate cortex, and insula in study participants who showed symptoms of a major depressive episode compared to healthy control participants. The implication is that the depressed people with elevated translocator protein binding have more brain inflammation, probably via microglial activation.

The antibiotic minocycline reduces microglial activation. It would be interesting to see if minocycline might have antidepressant effects in people with depression symptoms and elevated translocator protein binding.

Neuropsychological Deficits After Concussion Are Correlated with White Matter Abnormalities

July 31, 2015 · Posted in Brain Imaging · Comment 
DTI scan

DTI brain scan can show damage to white matter following a concussion.

Many people suffer problems with mental functioning after an apparent concussion (otherwise known as mild traumatic brain injury, or mTBI) that does not show abnormalities on traditional brain imaging measures such as the MRI. New technology called diffusion tensor imaging (DTI) shows that the integrity of white matter tracts may be disturbed by concussions. White matter comprises parts of the brain where myelin wraps around axons, as opposed to grey matter, which reflects the presence of neuronal cell bodies.

In a longitudinal study published in the Journal of Neurotrauma, Vigneswaran Veeramuthu and colleagues compared 61 people with an mTBI to 19 healthy controls. The mTBI participants had their neuropsychological faculties assessed an average of 4.35 hours after their trauma, and participated in DTI scans an average of 10 hours after the trauma. Both the neuropsychological assessment and the DTI scan were repeated six months later. When the acute and follow-up assessments were compared to the same assessments in control participants, the two groups showed differences in numerous white matter tracts at the six-month mark. There was also an association between the degree of abnormality observed on the DTI scans and decrements in performance on the tests of neuropsychological functioning both immediately after the trauma and six months later.

The researchers concluded that their results “provide new evidence for the use of DTI as an imaging biomarker and indicator of [white matter] damage occurring in the context of mTBI, and [the results] underscore the dynamic nature of brain injury and possible biological basis of chronic neurocognitive alterations.”

Editor’s Note: People should be aware of these findings, which confirm earlier studies, and begin rehabilitative treatment as soon as possible after a concussion. New research should target white matter tract changes, with the goal of secondary prevention, i.e. limiting damage to the brain after a traumatic injury has occurred. There are several promising drugs that can prevent damage if administered immediately after an mTBI, including the antioxidant supplement N-acetylcysteine (NAC), which has shown promise in preliminary clinical and laboratory studies, and many others, including lithium and valproate, as reported by De-Maw Chuang and this editor Robert M. Post in a 2015 article in the Journal of Neurology and Stroke titled “Preventing the Sequelae of Concussions and Traumatic Brain Injury.”

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