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Newly isolated human gut bacterium reveals possible connection to depression -- ScienceDaily

The research team from the U.S. Department of Energy's (DOE) Argonne National Laboratory, Northeastern University and elsewhere made the connection by first isolating the KLE1738, a bacterium that has a surprising dependency upon a brain chemical called gamma-aminobutyric acid (GABA). "The association of microbial GABAmetabolism with mental health is highly compelling," said Jack Gilbert, group leader for microbial ecology at Argonne who also holds new faculty appointments at the University of California, San Diego, in the Department of Pediatrics and at Scripps Institution of Oceanography. "The general ability of the microbiome to produce and/or consume GABA has not been as broadly described before, and a bacterium dependent on GABAhas never been reported."

Stimulating the vagus nerve in the neck might help ease pain associated with PTSD -- ScienceDaily

Lerman especially wants to know how the emotional pain experience may be influenced by the vagus nerve, which runs down both sides of our necks from the brainstem to the abdomen. The vagus nerve also plays a critical role in maintaining heart rate, breathing rate, digestive tract movement and many other basic body functions. In a study published February 13, 2019 in PLOS ONE, Lerman and colleagues tested noninvasive vagus nerve stimulation as a method for dampening the sensation of pain. "It's thought that people with certain differences in how their bodies -- their autonomic and sympathetic nervous systems -- process pain may be more susceptible to PTSD," Lerman said. "And so we wanted to know if we might be able to re-write this 'mis-firing' as a means to manage pain, especially for people with PTSD." Lerman led the study with Alan N. Simmons, PhD, director of the fMRI Research Laboratory at Veterans Affairs San Diego Healthcare System and associate professor of psychiatry at UC San Diego School of Medicine.

Cannabis use in teens linked to risk of depression in young adults: Cannabis use among adolescents is found to be associated with increased risk of depression and anxiety in adulthood -- ScienceDaily

'Regular use during adolescence is associated with lower achievement at school, addiction, psychosis and neuropsychological decline, increased risk of motor vehicle crashes, as well as the respiratory problems that are associated with smoking.' The active ingredient in cannabis,THC, mediates most of psychoactive and mood-related effects of cannabis and also has addictive properties. Preclinical studies in laboratory animals reported an association between pubertal exposure to cannabinoids and adult-onset depressive symptoms. It is thought that cannabis may alter the physiological neurodevelopment (frontal cortex and limbic system) of adolescent brains.

Do differences in gait predict the risk of developing depression in later life? -- ScienceDaily

Gait parameters and mental health both have significant impacts on functional status in later life. The study's findings suggest that gait problems may represent a potentially modifiable risk factor for depression.

Healthy diet can ease symptoms of depression -- ScienceDaily

The study found that all types of dietary improvement appeared to have equal effects on mental health, with weight-loss, fat reduction or nutrient-improving diets all having similar benefits for depressive symptoms. "This is actually good news" said Dr Firth; "The similar effects from any type of dietary improvement suggests that highly-specific or specialised diets are unnecessary for the average individual. "Instead, just making simple changes is equally beneficial for mental health. In particular, eating more nutrient-dense meals which are high in fibre and vegetables, while cutting back on fast-foods and refined sugars appears to be sufficient for avoiding the potentially negative psychological effects of a 'junk food' diet.

Gut Bacteria Linked to Depression Identified – Neuroscience News

Mireia Valles-Colomer (VIB-KU Leuven): ‘Many neuroactive compounds are produced in the human gut. We wanted to see which gut microbes could participate in producing, degrading, or modifying these molecules. Our toolbox not only allows to identify the different bacteria that could play a role in mental health conditions, but also the mechanisms potentially involved in this interaction with the host. For example, we found that the ability of microorganisms to produce DOPAC, a metabolite of the human neurotransmitter dopamine, was associated with better mental quality of life.’

Lasting impact of concussions on young adults -- ScienceDaily

In their study, recently published in the European Journal of Neuroscience, researchers looked at young adults ranging in age from 18 to 24 who had sustained at least two concussions with the most recent one being at least a month before the testing. The participants were asked to switch between two tasks which included telling the difference between colors and shapes, like red and green and circle or square. Cognitive changes, like working memory and processing speed, were noted and oscillatory activity, or brainwaves, were monitored with an electroencephalogram (EEG), which tests for changes in the brainwaves. In both the concussion group and the control group, researchers looked for differences in three different types of brainwaves and their effects on executive function, which is the ability to control cognitive functions like attention, inhibition, performance, flexibility, stability, working memory, and planning. They found an overall lower performance rate from those in the concussion group during the task-switching exercise. They were less accurate and processing performance was low.

Pot withdrawal eased for dependent users | YaleNews

Withdrawal symptoms are marked by craving for marijuana, irritability, anger, depression, insomnia, and decrease in appetite and weight. In 2015, about 4 million people in the United States met the diagnostic criteria for a cannabis use disorder, and almost 150,000 voluntarily sought treatment for their cannabis use. According to recent national data, approximately one-third of all current cannabis users meet diagnostic criteria for CUD.

Effective new target for mood-boosting brain stimulation found -- ScienceDaily

"Stimulation induced a pattern of activity in brain regions connected to OFC that was similar to patterns seen when patients naturally experienced positive mood states," says Vikram Rao, of the University of California, San Francisco. "Our findings suggest that OFC is a promising new stimulation target for treatment of mood disorders." The team led by Rao and Kristin Sellers in the lab of Edward Chang studied 25 patients with epilepsy who had electrodes placed in the brain for medical reasons to pinpoint the origin of their seizures. Many of those patients also suffered from depression, which is often seen in people with epilepsy. With the patients' consent, Chang's team took advantage of those electrodes to deliver small electrical pulses to areas of the brain thought to be involved in regulating mood. Previous studies have explored deep brain stimulation (DBS) for mood disorders, but its success depends critically on target selection. Targets in other mood-related areas deep in the brain hadn't always led to reliable improvements. In the new study, the researchers focused their attention and the electrical stimulation on the OFC. The OFC is a key hub for mood-related circuitry. But it's also widely regarded as one of the least well-understood brain regions. "Although OFC is a more superficial target, it shares rich interconnections with several brain regions implicated in emotion processing," Sellers says. That made this relatively small brain area an attractive target for therapeutic stimulation. The researchers used the implanted electrodes to stimulate OFC and other brain regions while collecting verbal mood reports and questionnaire scores. Those studies found that unilateral stimulation of the lateral OFC produced acute, dose-dependent mood-state improvement in subjects with moderate-to-severe baseline depression. The changes in brain activity the researchers observed after stimulation closely resembled those seen when people are in a good mood.

Association of Testosterone Treatment With Alleviation of Depressive Symptoms in Men: A Systematic Review and Meta-analysis | Depressive Disorders | JAMA Psychiatry | JAMA Network

Random-effects meta-analysis of 27 RCTs including 1890 men suggested that testosterone treatment is associated with a significant reduction in depressive symptoms compared with placebo (Hedges g, 0.21; 95% CI, 0.10-0.32), showing an efficacy of odds ratio (OR), 2.30 (95% CI, 1.30-4.06). There was no significant difference between acceptability of testosterone treatment and placebo (OR, 0.79; 95% CI, 0.61-1.01). Meta-regression models suggested significant interactions for testosterone treatment with dosage and symptom variability at baseline. In the most conservative bias scenario, testosterone treatment remained significant whenever dosages greater than 0.5 g/wk were administered and symptom variability was kept low.

May A.I. Help You? - The New York Times

In a study with 70 young adults, Darcy found that after two weeks of interacting with the bot, the test subjects had lower incidences of depression and anxiety. […]Last spring, when Darcy put Woebot online, free to all, its use immediately exploded; in the first week, more than 50,000 people talked to it. (“Do you realize,” Ng told Darcy, “that Woebot spoke to more people today than a human therapist could in a lifetime?”) Nowadays, Woebot exchanges between one and two million messages a week with users, ranging from divorcées to the bereaved to young men, a population that rarely seeks treatment. Many tell Darcy that it’s easier to talk to a bot than a human; they don’t feel judged.

Brain signature of depressed mood unveiled in new study: Direct recordings of human brain activity link memory, emotion, and anxiety during bouts of low mood -- ScienceDaily

Then, to compare results across the unique brains and distinct electrode placements of all 21 research participants, the researchers mapped each subject's ICNs onto neural connectivity diagrams. Comparing these standardized records of network activity across subjects revealed several "cliques" -- groups of brain regions that repeatedly became synchronized at specific frequencies, and were therefore likely to represent functional brain networks. One such clique was highly active and coordinated in 13 research participants, all of whom had also scored high on a psychological assessment of baseline anxiety conducted prior to the start of the study. In these same individuals, changes in the activity of this brain network were also highly correlated with day-to-day bouts of low or depressed mood. This mood-related network was characterized by so-called beta waves -- synchronized oscillations between 13 and 30 cycles per second -- in the hippocampus and amygdala, two deep brain regions which have long been linked, respectively, to memory and to negative emotion. Sohal said the research team was at first taken aback by the clarity of the finding. "We were quite surprised to identify a single signal that almost completely accounted for bouts of depressed mood in such a large set of people," said Sohal. "Finding such a powerfully informative biomarker was more than what we'd expected at this stage of the project." Surprisingly, this powerful link between of mood-associated beta waves in the amygdala and hippocampus was entirely absent from eight other research participants, all of whom had comparatively low preexisting anxiety, suggesting new questions about how the brains of people prone to anxiety may differ from others in how they process emotional situations.

Gut branches of vagus nerve essential components of brain's reward and motivation system -- ScienceDaily

"Our study reveals, for the first time, the existence of a neuronal population of 'reward neurons' amid the sensory cells of the right branch of the vagus nerve," says Ivan de Araujo, DPhil, Senior Faculty in the Department of Neuroscience at the Icahn School of Medicine at Mount Sinai and senior author of the paper. "We focused on challenging the traditional view that the vagus nerve is unrelated to motivation and pleasure and we found that stimulation of the nerve, specifically its upper gut branch, is sufficient to strongly excite reward neurons lying deep inside the brain." The branches of the vagus nerve are intricately intermingled, making it extremely difficult to manipulate each organ separately. To address this challenge, the research team employed a combination of virally delivered molecular tools that allowed them to exclusively target the vagal sensory neurons connected to the stomach and upper intestine. Specifically, researchers combined different viruses carrying molecular tools in a way that allowed them to optically activate vagal neurons connected to the gut while vagal neurons leading to other organs remained mute. The approach, a state-of-the-art technique known as "optogenetics," allows investigators to use light to manipulate the activity of a prespecified set of neurons. The study revealed that the newly identified reward neurons of the right vagus nerve operate under the same constraints attributed to reward neurons of the central nervous system, meaning they link peripheral sensory cells to the previously mapped populations of reward neurons in the brain. Strikingly, neurons of the left vagus were associated with satiety, but not with reward. The research team's anatomical studies also revealed, for the first time, that the right and left vagal branches ascend asymmetrically into the central nervous system.

In depression the brain region for stress control is larger -- ScienceDaily

So far, it is known that people more predisposed to depression show a dysregulation of the endogenous stress response system, otherwise known as the hypothalamic-pituitary-adrenal axis (HPA axis), which is normally triggered when we are faced with a stressful situation. This response increases the amount of cortisol, providing the body with more energy when faced with a potential threat or challenge. Once the challenging situation has passed, several control mechanisms in the HPA axis normally ensure the system returns to a balanced state. In people who suffer with depressive disorder or who are more predisposed, this is not the case. Instead, a malfunction of the feedback mechanism results in a stress response operating at full throttle, even when there is no apparent stressful situation. Until now, the underlying reason for this hyperactive stress response system and the role of the hypothalamus as its overall control unit has remained unclear.

Breakthrough brain research could yield new treatments for depression -- ScienceDaily

According to Shanechi, for clinical practitioners, a powerful decoding tool would provide the means to clearly delineate, in real time, the network of brain regions that support emotional behavior. "Our goal is to create a technology that helps clinicians obtain a more accurate map of what is happening in a depressed brain at a particular moment in time and a way to understand what the brain signal is telling us about mood. This will allow us to obtain a more objective assessment of mood over time to guide the course of treatment for a given patient," Shanechi said. "For example, if we know the mood at a given time, we can use it to decide whether or how electrical stimulation should be delivered to the brain at that moment to regulate unhealthy, debilitating extremes of emotion. This technology opens the possibility of new personalized therapies for neuropsychiatric disorders such as depression and anxiety for millions who are not responsive to traditional treatments."

Model can more naturally detect depression in conversations: Neural network learns speech patterns that predict depression in clinical interviews -- ScienceDaily

One key insight from the research, Alhanai notes, is that, during experiments, the model needed much more data to predict depression from audio than text. With text, the model can accurately detect depression using an average of seven question-answer sequences. With audio, the model needed around 30 sequences. "That implies that the patterns in words people use that are predictive of depression happen in shorter time span in text than in audio," Alhanai says. Such insights could help the MIT researchers, and others, further refine their models.

Exercise as Medical Treatment for Depression - ScienceDirect

The investigators randomized 101 patients with various degrees of depression into 3 treatment groups: sertraline (50 to 200 mg), group exercise 3 times per week, or placebo. Baseline depressive symptoms were assessed both by the Hamilton Rating Scale for Depression and a structured interview. Approximately one-half of the patients had major depression. At 4-month follow-up, there were comparable reductions in depressive symptoms among the patients who received sertraline and those who underwent exercise, and both groups had greater reductions in depressive symptoms compared with placebo. These results are concordant with those of 2 prior randomized studies these investigators performed to compare exercise with antidepressant medication in noncardiac subjects with depression (18, 19).

Painting a Nuanced Picture of Brain System Regulation Moods and Movements - Neuroscience News

What’s more, the group found that the serotonin neurons themselves were more complex than originally thought. Rather than just transmitting messages with serotonin, the cortical-projecting neurons also released a chemical messenger called glutamate – making them one of the few known examples of neurons in the brain that release two different chemicals. “It raises the question of whether we should even be calling these serotonin neurons because neurons are named after the neurotransmitters they release,” Ren said. Taken together, these findings indicate that the brain’s serotonin system is not made up of a homogenous population of neurons but rather many subpopulations acting in concert. Luo’s team has identified two groups, but there could be many others. In fact, Robert Malenka, a professor and associate chair of psychiatry and behavioral sciences at Stanford’s School of Medicine, and his team recently discovered a group of serotonin neurons in the dorsal raphe that project to the nucleus accumbens, the part of the brain that promotes social behaviors.

Depressed patients see quality of life improve with nerve stimulation: Study focuses on people not treated effectively with antidepressants -- ScienceDaily

The researchers followed 328 patients implanted with vagus nerve stimulators, many of whom also took medication. They were compared with 271 similarly resistant depressed patients receiving only treatment as usual. In assessing quality of life, the researchers evaluated 14 categories, including physical health, family relationships, ability to work and overall well-being. "On about 10 of the 14 measures, those with vagus nerve stimulators did better," Conway said. "For a person to be considered to have responded to a depression therapy, he or she needs to experience a 50 percent decline in his or her standard depression score. But we noticed, anecdotally, that some patients with stimulators reported they were feeling much better even though their scores were only dropping 34 to 40 percent." A vagus nerve stimulator is surgically implanted under the skin in the neck or chest. Stimulation of the vagus nerve originally was tested in epilepsy patients who didn't respond to other treatments. The FDA approved the device for epilepsy in 1997, but while testing the therapy, researchers noticed that some epilepsy patients who also had depression experienced fairly rapid improvements in their depression symptoms.

Brain connectivity study helps explain the neural link between depression and poor sleep quality

The researchers examined data from 1,017 participants who were included in the March 2017 public data release from the Human Connectome Project. They found that both poor sleep quality and depressive symptoms were associated with neural connectivities involving the lateral orbitofrontal cortex, the dorsolateral prefrontal cortex, the cingulate cortex, and the precuneus. “Our analysis shows that the functional connections between the areas of the brain associated with short-term memory, the self, and negative emotions are increased in both poor sleep and depressive participants. So people with poor sleep or depression may focus too much on the negative things and dwell on bad thoughts, which leads to a poor quality of sleep,” Feng told PsyPost.

Getting to the Roots of Pessimism - Neuroscience News

MIT neuroscientists have now pinpointed a brain region that can generate this type of pessimistic mood. In tests in animals, they showed that stimulating this region, known as the caudate nucleus, induced animals to make more negative decisions: They gave far more weight to the anticipated drawback of a situation than its benefit, compared to when the region was not stimulated. This pessimistic decision-making could continue through the day after the original stimulation. The findings could help scientists better understand how some of the crippling effects of depression and anxiety arise, and guide them in developing new treatments. “We feel we were seeing a proxy for anxiety, or depression, or some mix of the two,” says Ann Graybiel, an MIT Institute Professor, a member of MIT’s McGovern Institute for Brain Research, and the senior author of the study, which appears in the Aug. 9 issue of Neuron. “These psychiatric problems are still so very difficult to treat for many individuals suffering from them.”

The Lancet Psychiatry: Exercise linked to improved mental health, but more may not always be better | EurekAlert! Science News

Exercising for 30-60 minutes was associated with the biggest reduction in poor mental health days (associated with around 2.1 fewer days of poor mental health compared with people who did not exercise). Small reductions were still seen for people who exercised more than 90 minutes a day, but exercising for more than three hours a day was associated with worse mental health than not exercising at all. The authors note that people doing extreme amounts of exercise might have obsessive characteristics which could place them at greater risk of poor mental health.

Lack of a Single Molecule May Indicate Severe and Treatment Resistant Depression - Neuroscience News

Naturally produced by the body, LAC performs a number of crucial tasks in the brain. For example, the molecule regulates energy metabolism and interacts with DNA to promote the expression of important genes. Specifically, it acts on a gene that controls levels of the neurotransmitter glutamate–a chemical implicated in almost everything that the brain does. McEwen, the Alfred E. Mirsky Professor, and Nasca, a postdoctoral fellow of the American Foundation for Suicide Prevention, have studied the link between LAC and mood disorders using animal models. In one study, they showed that LAC supplements ameliorate depressive symptoms in mice by reversing brain-cell impairment caused by an excess of glutamate. In a separate rodent study, they observed that LAC treatment reduces depressive behavior and stress-associated neural dysfunction in the medial amygdala, a brain region involved in social interactions. These findings strongly suggest that LAC deficits contribute to a depression-like state in mice, leading the scientists to wonder whether the molecule plays a similar role in humans.

Neural inflammation plays critical role in stress-induced depression -- ScienceDaily

These results show that repeated social defeat stress activates microglia in the medial prefrontal cortex via the innate immune receptors TLR2/4. This triggers the expression of inflammation-related cytokines IL-1? and TNF?, leading to the atrophy and impaired response of neurons in the medial prefrontal cortex, and causing depressive behavior. Professor Furuyashiki says: "These findings demonstrate the importance of neural inflammation caused by the innate immune system for stress-induced depression. This could lead to the development of new antidepressant medication targeting innate immune molecules."

Video: The Underlying Mechanisms of Depression

While it’s likely that there may be more going on with depression than just inflammation by itself, it could be an incredibly useful lens through which to look at promising avenues to potentially treat or prevent it, since controlling systemic inflammation shows promise as being both important for longevity and health in general. Moreover, inflammation can be clinically monitored by well-known biomarkers for systemic inflammation, making it amenable to potentially tracking therapeutic success: the risk of major depression has been shown to increase by 44% for each standard deviation increase in log c-reactive protein.

Suicide is a national epidemic. We need to treat it like one. - The Washington Post

These two treatments are obviously different, but they both point to an entirely new chemical axis in the brain that could be targeted to treat depression: the glutamine/glutamate axis. Commonly abbreviated Glx, these chemicals are suppressed in people with severe depression and post-traumatic stress disorder (PTSD) and do not increase when patients take serotonin-targeting antidepressants. The company I lead is working to develop drugs to raise Glx without the damaging side effects of ketamine or ECT. The science is promising: The FDA recently issued a biomarker letter of support, its first in psychiatry under the 21st Century Cures Act, recognizing that an increased level of Glx correlates with decreased levels of depression and that drugs targeting Glx are linked to a reduction in depression and suicidal ideation.