Summary: Attention-deficit hyperactivity disorder (ADHD) is a prevalent disorder that is generally diagnosed on the foundation of developmentally-inappropriate as well as persistent levels of overactivity, inattention and impulsivity.
Attention-deficit hyperactivity disorder (ADHD) is a prevalent disorder that is generally diagnosed on the foundation of developmentally-inappropriate as well as persistent levels of overactivity, inattention and impulsivity. The etiology and patho-physiology of ADHD is not yet completely understood. Evidence has been found in the favor of a genetic basis for ADHD. But it is quite likely that it involves more than one gene of small individual effect.
Apart from that differences in the dimensions of the caudate nucleus, frontal lobes, and cerebellar vermis have been depicted. Neuropsychological testing has brought forward a number of important differences between children who are diagnosed with ADHD and those without ADHD.
These have been evidently seen to occur in two main domains: executive function and motivation. However, neither of the aforementioned factors are specific to ADHD.
In the context of the recent advances in the neurobiology of reinforcement, psychologists concentrated on the altered reinforcement mechanisms. Among the important motivational differences, pieces of evidence purports that there might be an altered response to reinforcement. Which might play a central role in the depiction of the symptoms of ADHD. To be specific, sensitivity towards the delay of reinforcement might be accepted as a reliable finding.
A detailed study depicted that dopamine cell firing activity is commonly associated with reinforcing events. This can be accounted for earlier time-points in the behavioural sequence as the reinforcement involved becomes quite predictable.
Contact: Gail Tripp EG Tripp, OIST Graduate University.
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Depression can be prevented through a healthy lifestyle, find out why
Source: Cambridge University
Summary: Depression can be reduced. as per new research, a healthy lifestyle involves moderate alcohol consumption, a proper diet, regular exercise, proper sleep, and frequent social connections, while avoiding smoking and sedentary behavior.
Depression affects approximately one in every 20 adults and has a significant negative impact on public health globally. It is difficult to pinpoint the precise biological and environmental factors that contribute to the development of depression.
The UK Biobank, a biological database and research resource with anonymized genetic, lifestyle, and health information on its users, was used by the researchers to gain a better understanding of the connection between these characteristics and depression.
The team was able to pinpoint seven healthy lifestyle factors associated with a lower risk of depression by analyzing data from nearly 290,000 individuals, 13,000 of whom had depression, over the course of a nine-year period. They included:
• moderate alcohol consumption • healthy diet • regular physical activity • healthy sleep • never smoking • low-to-moderate sedentary behaviour • frequent social connection.
Sleeping well—between seven and nine hours every night—made the biggest difference of all these variables, lowering the risk of depression, including single depressive episodes and treatment-resistant depression, by 22%.
The best defense against recurrent depressive disorder was regular social contact, which generally reduced the risk of depression by 18%.
Low to moderate sedentary behavior reduced risk of depression by 13%, healthy diet by 6%, regular exercise by 14%, never smoking by 20%, and moderate alcohol consumption by 11%.
An individual was placed in one of three groups—unfavorable, intermediate, or favorable—based on how many healthy lifestyle factors they followed. When compared to people who lead unfavorable lifestyles, people in the intermediate group were about 41% less likely to experience depression, while people who lead a favourable lifestyle were 57% less likely.
The team then performed a genetic risk assessment on each participant by looking at their DNA. The number of genetic variations a person possessed that are known to be associated with a higher risk of depression was the basis for this score. When compared to those with the highest genetic risk scores, those with the lowest scores had a 25% lower risk of developing depression, which is a much smaller effect than lifestyle.
The group also discovered that leading a healthy lifestyle can lower the risk of depression in people with high, medium, and low genetic risk for depression. This study emphasizes the value of leading a healthy lifestyle regardless of a person’s genetic risk for depression.
Professor Barbara Sahakian, from the Department of Psychiatry at the University of Cambridge, said: “Although our DNA—the genetic hand we’ve been dealt—can increase our risk of depression, we’ve shown that a healthy lifestyle is potentially more important. “Some of these lifestyle factors are things we have a degree of control over, so trying to find ways to improve them—making sure we have a good night’s sleep and getting out to see friends, for example—could make a real difference to people’s lives.”
First, they looked at MRI brain scans from slightly less than 33,000 participants and discovered several areas of the brain where a larger volume—more neurons and connections—was associated with a healthy lifestyle. These included the thalamus, hippocampus, amygdala, and pallidum.
The team then looked for markers in the blood that suggest immune system or metabolism (how our bodies process food and create energy) issues. The body produces the molecule Creactive protein in response to stress, and triglycerides, one of the main types of fat the body uses to store energy for later, were among the markers that were discovered to be linked to lifestyle.
Several earlier studies have provided evidence for these connections. For instance, stress in life can impair our capacity to control blood sugar, which can deteriorate immune function and hasten the aging process of cells and molecules in the body.
The body’s capacity to react to stress can be harmed by insufficient exercise and sleep. There is evidence that loneliness and a lack of social support raise immune-deficiency markers and increase the risk of infection.
The research team discovered that the most significant relationship between lifestyle and immune and metabolic processes existed.
To put it another way, leading a poorer lifestyle has an effect on our immune system and metabolism, which raises our risk of developing depression.
Source: Cambridge University
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Cannabinoid molecules can calm your own body during stress.
Summary: Your brain may release its own cannabinoid molecules in response to stress to help you relax, activating the same brain receptors as THC derived from cannabis plants. But it was not well understood how these cannabinoid molecules affected brain activity.
Source: Northwestern University
Your brain may release its own cannabinoid molecules in response to stress to help you relax, activating the same brain receptors as THC derived from cannabis plants. But it was not well understood how these cannabinoid molecules affected brain activity.
A recent mouse study from Northwestern Medicine has shown that the amygdala, a crucial emotional brain region, releases endogenous (body-produced) cannabinoid molecules under stress, which reduces the intensity of the incoming stress signal from the hippocampus, the brain’s memory and emotional region.
These findings lend more credence to the idea that the body produces these endogenous cannabinoid molecules as a stress-reduction mechanism.
Stress exposure increases the risk of psychiatric disorders such as post-traumatic stress disorder (PTSD), generalized anxiety disorder, and major depressive disorder developing or getting worse.
“Understanding how the brain adapts to stress at the molecular, cellular, and circuit level could provide critical insight into how stress is translated into mood disorders and may reveal novel therapeutic targets for the treatment of stress-related disorders,” said corresponding study author Dr. Sachi Patel, a psychiatrist at Northwestern Medicine and the chair of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.
In order to demonstrate that particular high-frequency patterns of amygdala activity can produce these molecules, Northwestern researchers used a novel protein sensor that can spot the presence of these cannabinoid molecules at specific brain synapses in real time. Additionally, the sensor demonstrated that these molecules were released by mice under various forms of stress.
The mice’s ability to handle stress and motivational deficits was affected when scientists removed the cannabinoid receptor type 1 that these cannabinoids target.
Mice adopted more passive and immobile responses to stress and had a lower preference for drinking sweetened sucrose water after stress exposure when the receptor target of these endogenous cannabinoids at hippocampal-amygdala synapses was eliminated. The latter finding might be connected to anhedonia, or the decrease in pleasure, which is frequently felt by people with stress-related disorders like depression and PTSD.
The endocannabinoid system has been recognized as one of the most important signaling systems that is a top drug-development candidate for stress-related psychiatric disorders.
“Determining whether increasing levels of endogenous cannabinoids can be used as potential therapeutics for stress-related disorders is a next logical step from this study and our previous work,” said Patel, also the Lizzie Gilman Professor of Psychiatry and Behavioral Sciences. “There are ongoing clinical trials in this area that may be able to answer this question in the near future.”
Source: Northwestern University
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Depressed Individuals Maintain Focus on Negatives Even After Recovery, Study Finds
Summary: Depressed Individuals Maintain Focus on Negatives Even After Recovery, a study finds. In contrast to people who have never suffered a major depressive episode, people who have recovered from one typically spend more time processing negative information and less time processing positive information, which increases the likelihood of a recurrence.
Source: American Psychological Association
Lead author Alainna Wen, PhD, a postdoctoral scholar at the Anxiety and Depression Research Center at the University of California, Los Angeles, said, “Our research indicates that individuals with a previous history of depression dedicate a significant amount of time to analyzing negative stimuli, such as expressions of sadness, in comparison to positive stimuli like displays of happiness. This contrast is more pronounced when compared to emotionally healthy individuals with no such history. This divergence in processing suggests a heightened susceptibility to potential future depressive episodes. This susceptibility arises from the inherent nature of depression, which involves an abundance of negative thoughts and emotions, coupled with a scarcity of positive ones.”
The Journal of Psychopathology and Clinical Science published the research.
One of the most prevalent mental illnesses in the US is major depression. The National Institute of Mental Health estimates that 21 million American people (8.4% of the country’s population) reported having had serious depression at least once in 2020. Major depression can hinder or limit a person’s capacity to do important life tasks. It is characterized by a minimum of two weeks of a gloomy mood or a lack of interest in or enjoyment from daily activities.
Wen reports that relapse rates for major depressive disorder are still high despite the availability of effective therapies for the condition. After their first major depressive episode, over 50% of people will go on to have several episodes, and they frequently relapse within two years of getting better. To enhance treatment and prevent recurrence, researchers need to gain a deeper understanding of the risk factors associated with major depressive illness.
Research on Depressed Individuals
Researchers performed a meta-analysis of 44 trials, comprising 2285 healthy controls and 2081 patients with a history of severe depressed disorder, for this publication. Every study looked at how quickly people responded to neutral, positive, or negative stimuli. In several instances, participants were requested to press a separate button to represent a happy, sad, or neutral human face. In other cases, participants responded to favorable, unfavorable, or neutral words.
Regardless of whether the stimuli were pleasant, neutral, or negative, healthy participants reacted to both emotional and non-emotional stimuli faster than those with a history of depression. However, compared to controls, individuals who had previously experienced major depressive disorder took longer to process unpleasant emotional cues. When compared to individuals in major depression remission, healthy controls showed a significant difference in the amount of time they spent processing positive versus negative emotional stimuli; however, this difference did not show up when comparing the amount of time spent processing positive versus neutral or negative versus neutral stimuli.
According to Wen, the results generally imply that people with recurrent major depressive disorder not only exhibit a stronger bias for focusing on negative information over positive or neutral information, but they also appear to be less able to manage the information they absorb than people in good health.
“The results of this study have implications for depressed people’s treatment,” Wen stated. Merely centering on diminishing the analysis of negative data might not be adequate to avert a relapse of depression. Alternatively, approaches that enhance the processing of positive information could prove advantageous for patients.”
Source: American Psychological Association
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