Posts tagged PTSD
Articles and news from the latest research reports.
Stroke Survivors with PTSD More Likely to Avoid Treatment
A new survey of stroke survivors has shown that those with post-traumatic stress disorder (PTSD) are less likely to adhere to treatment regimens that reduce the risk of an additional stroke. Researchers found that 65 percent of stroke survivors with PTSD failed to adhere to treatment, compared with 33 percent of those without PTSD. The survey also suggests that nonadherence in PTSD patients is partly explained by increased ambivalence toward medication. Among stroke survivors with PTSD, approximately one in three (38 percent) had concerns about their medications. Results of the study, led by Columbia University Medical Center researchers, are published today in the British Journal of Health Psychology.
According to data from the American Stroke Association, nearly 795,000 Americans each year suffer a new or recurrent stroke. Stroke is the fourth-leading cause of death and the top cause of disability in the United States. Survivors of strokes are often prescribed treatment regiments, including antiplatelet agents, antihypertensive agents, and statins, which help reduce the risk of subsequent strokes. Previous research has shown that PTSD triggered by medical events—which affects 18 percent of stroke survivors—may impair recovery.
“Unfortunately, too many stroke survivors are not compliant with these regimens, even though we know that adherence to post-stroke treatment regimens is one of the most important components of reducing the risk of a future stroke,” said Ian M. Kronish, MD, MPH, assistant professor of medicine (Center for Behavioral Cardiovascular Health) and one of the study’s authors.
“For those with PTSD, this study shows that concerns about medications are a significant barrier to treatment adherence. Stroke survivors should be assessed for concerns about medications and PTSD symptoms, so that interventions may be introduced as early as possible to get patients back on track to avoid future stroke events.”
Scientists explore the illusion of memory
A memory might seem like a permanent, precious essence carved deep into the circuits of the brain. But it is not. Instead, scientists are discovering that a memory changes every time you think about it.
"Every time you recall a memory, it becomes sensitive to disruption. Often that is used to incorporate new information into it." That’s the blunt assessment from one of the world’s leading experts on memory, Dr. Eric Kandel from Columbia University.
And that means our memories are not abstract snapshots stored forever in a bulging file in our mind, but rather, they’re a collection of brain cells — neurons that undergo chemical changes every time they’re engaged.
So when we think about something from the past, the memory is called up like a computer file, reviewed and revised in subtle ways, and then sent back to the brain’s archives, now modified slightly, updated, and changed.
As scientists increasingly understand the biological process of memory, they are also learning how to interrupt it, and that means they might one day be able to ease the pain of past trauma, or alter destructive habits and addictions, as though shaking an Etch A Sketch, erasing the scribbles on the mind, and starting fresh.
In his McGill University lab, researcher Karim Nader routinely erases the memory of his laboratory rats. But first he has to give them a memory and he does that by putting them in an isolation cubicle, playing a tone, and then delivering a small electrical shock to their feet.
A New Focus on the ‘Post’ in Post-Traumatic Stress
Psychological trauma dims tens of millions of lives around the world and helps create costs of at least $42 billion a year in the United States alone. But what is trauma, exactly?
Both culturally and medically, we have long seen it as arising from a single, identifiable disruption. You witness a shattering event, or fall victim to it — and as the poet Walter de la Mare put it, “the human brain works slowly: first the blow, hours afterward the bruise.” The world returns more or less to normal, but you do not.
In 1980, the Diagnostic and Statistical Manual of Mental Disorders defined trauma as “a recognizable stressor that would evoke significant symptoms of distress in almost everyone” — universally toxic, like a poison.
But it turns out that most trauma victims — even survivors of combat, torture or concentration camps — rebound to live full, normal lives. That has given rise to a more nuanced view of trauma — less a poison than an infectious agent, a challenge that most people overcome but that may defeat those weakened by past traumas, or other factors.
Now, a significant body of work suggests that even this view is too narrow — that the environment just after the event, particularly other people’s responses, may be just as crucial as the event itself.
The idea was demonstrated vividly in two presentations this fall at the Interdisciplinary Conference on Culture, Mind and Brain at the University of California, Los Angeles. Each described reframing a classic model of traumatic experience — one in lab rats, the other in child soldiers.
Research identifies a way to block memories associated with PTSD or drug addiction
New research from Western University could lead to better treatments for Post-Traumatic Stress Disorder (PTSD) and drug addiction by effectively blocking memories. The research performed by Nicole Lauzon, a PhD candidate in the laboratory of Steven Laviolette at Western’s Schulich School of Medicine & Dentistry has revealed a common mechanism in a region of the brain called the pre-limbic cortex, can control the recall of memories linked to both aversive, traumatic experiences associated with PTSD and rewarding memories linked to drug addiction. More importantly, the researchers have discovered a way to actively suppress the spontaneous recall of both types of memories, without permanently altering memories. The findings are published online in the journal Neuropharmacology.
“These findings are very important in disorders like PTSD or drug addiction. One of the common problems associated with these disorders is the obtrusive recall of memories that are associated with the fearful, emotional experiences in PTSD patients. And people suffering with addiction are often exposed to environmental cues that remind them of the rewarding effects of the drug. This can lead to drug relapse, one of the major problems with persistent addictions to drugs such as opiates,” explains Laviolette, an associate professor in the Departments of Anatomy and Cell Biology, and Psychiatry. “So what we’ve found is a common mechanism in the brain that can control recall of both aversive memories and memories associated with rewarding experience in the case of drug addiction.”
In their experiments using a rat model, the neuroscientists discovered that stimulating a sub-type of dopamine receptor called the “D1” receptor in a specific area of the brain, could completely prevent the recall of both aversive and reward-related memories. “The precise mechanisms in the brain that control how these memories are recalled are poorly understood, and there are presently no effective treatments for patients suffering from obtrusive memories associated with either PTSD or addiction,” says Lauzon. “If we are able to block the recall of those memories, then potentially we have a target for drugs to treat these disorders.”
Childhood trauma leaves mark on DNA of some victims
Abused children are at high risk of anxiety and mood disorders, as traumatic experience induces lasting changes to their gene regulation. Scientists from the Max Planck Institute of Psychiatry in Munich have now documented for the first time that genetic variants of the FKBP5 gene can influence epigenetic alterations in this gene induced by early trauma. In individuals with a genetic predisposition, trauma causes long-term changes in DNA methylation leading to a lasting dysregulation of the stress hormone system. As a result, those affected find themselves less able to cope with stressful situations throughout their lives, frequently leading to depression, post-traumatic stress disorder or anxiety disorders in adulthood. Doctors and scientists hope these discoveries will yield new treatment strategies tailored to individual patients, as well as increased public awareness of the importance of protecting children from trauma and its consequences.
Follow-up study finds lasting benefit from MDMA for people with PTSD
The follow-up study was based on an original trial held in 2010 where 20 patients suffering from long term PTSD were given MDMA (the main ingredient in the party drug ecstasy) as part of their psychotherapy sessions. The researchers reported at the time that 83% of the participants showed improvements in their condition two months later.
In this new work, the researchers revisited the original patients three and a half years later (one refused to participate leaving just 19) to see how well they were doing. They found that just two of the patients had suffered a relapse – the rest they say maintained the relief they had found in the original trial.
The research was sponsored by the group Multidisciplinary Association for Psychedelic Studies (MAPS), whose mission is to seek out treatments for a variety of mental ailments using non-traditional drug therapies. In addition to providing funds for the trials they also worked out agreements with the government to allow for legal testing of the drug (it currently has as a Schedule I status.)
Study leads Michael and Ann Mithoefer conducted the original trial out of their private practice office. Each trial was conducted with a single patient at a time and involved a non-pharmaceutical therapy session followed by one where the patient was given a dose of MDMA. Another traditional session was held later – the sessions that included use of the drug lasted up to eight hours because the effects of the drugs last that long.
The researchers believe that MDMA helps PTSD sufferers by allowing them to relive the emotionally traumatic experience that led to their condition in a more relaxed and receptive way. Because of the promising results, MAPS is calling on the government to relax its rules on the testing and use of MDMA for medical applications.
PTSD linked to smaller brain area regulating fear response
Recent combat veterans who are diagnosed with post traumatic stress disorder have significantly smaller volume in an area of the brain critical for regulating fear and anxiety responses, according to research led by scientists at Duke University and the Durham VA Medical Center.
The finding, published Nov. 5, 2012, in the journal Archives of General Psychiatry, for the first time provides clear evidence that smaller amygdala volume is associated with PTSD, regardless of the severity of trauma. But it’s not clear whether the physiological difference was caused by a traumatic event, or whether PTSD develops more readily in people who naturally have smaller amygdalas.
“Researchers found 20 years ago that there were changes in volume of the hippocampus associated with PTSD, but the amygdala is more relevant to the disorder,” said Rajendra A. Morey, M.D., M.S., assistant professor at Duke and lead author of the study. Morey said studies in animals have established the amygdala’s role in regulating fear, anxiety and stress responses, but its effect on human behavior is less well known.
“It’s associated with how fear is processed, especially abnormal fear processing.” Morey said. “So it makes sense to look at the structure of the amygdala.”
(Photo: U.S. Army)
Scientists reveal brain circuitry involved in post-traumatic stress and related disorders
Post-traumatic stress disorder (PTSD) is a severe anxiety disorder that can develop after experience of a traumatic or terrifying event, such as those experienced in combat or from sexual aggression. Such events can overwhelm the individual’s ability to cope and lead to a long-lasting disorder. Symptoms include re-experiencing the original trauma through flashbacks or nightmares, often triggered by seemingly innocuous events. PTSD can harm an individual’s relationships, ability to work, to sleep, and other aspects of life.
The lifetime prevalence of PTSD among adult Americans is 8 percent. Neither drug nor behavioral treatments currently available are consistently effective in treating PTSD. Therefore, scientists are studying brain changes associated with PTSD and related cognitive disorders, looking for clues to help in the development of new treatments.
Today’s findings show that:
- A fast-acting antidepressant, ketamine, appears to aid the formation of new nerve connections in the brain, helping to extinguish fearful memories. The mouse study could possibly lead to new PTSD treatments (Neil Fournier, PhD, abstract 399.09).
- In a mouse model, when dopamine neurons in the brain’s reward system are turned on and off with a genetically engineered “light switch,” depressive symptoms also come and go. The research highlights the importance of this neural circuit as a potential target for new depression treatments (Dipesh Chaudhury, PhD, abstract 522.01).
- Brain images of adolescents taken before and after the 2011 Japanese earthquake reveal that pre-existing weakness in certain brain connections could be a risk factor for intensified anxiety and PTSD after a traumatic life experience (Atsushi Sekiguchi, MD, PhD, abstract 168.12).
- Rodent studies show that repeated violent, competitive encounters drive changes in brain activity that shapes the ongoing behavior of losers and winners in distinct ways, and can contribute to depression and/or anxiety (Tamara Franklin, PhD, abstract 399.10).
Other recent findings discussed show:
- How exposure to stress causes molecular changes that weaken the ability of the prefrontal cortex to regulate behavior, thought, and emotion, while strengthening more primitive brain circuits (Amy Arnsten, PhD, abstract 310).
Breakthrough study identifies trauma switch
Research identifies the mechanism that protects our brains from turning stress and trauma into post-traumatic stress disorder
Researchers from the University of Exeter Medical School have for the first time identified the mechanism that protects us from developing uncontrollable fear.
Our brains have the extraordinary capacity to adapt to changing environments – experts call this ‘plasticity’. Plasticity protects us from developing mental disorders as the result of stress and trauma.
Researchers found that stressful events re-programme certain receptors in the emotional centre of the brain (the amygdala), which the receptors then determine how the brain reacts to the next traumatic event.
These receptors (called protease-activated receptor 1 or PAR1) act in the same way as a command centre, telling neurons whether they should stop or accelerate their activity.
Before a traumatic event, PAR1s usually tell amygdala neurons to remain active and produce vivid emotions. However, after trauma they command these neurons to stop activating and stop producing emotions – so protecting us from developing uncontrollable fear.
This helps us to keep our fear under control, and not to develop exaggerated responses to mild or irrelevant fear triggers – for example, someone who may have witnessed a road traffic accident who develops a fear of cars or someone who may have had a dog jump up on them as a child and who now panics when they see another dog.
The research team used mice in which the PAR1 receptors were genetically de-activated and found that the animals developed a pathological fear in response to even mild, aversive stimuli.
The study was led by Professor Robert Pawlak of University of Exeter Medical School. He said: “The discovery that the same receptor can either awaken neurons or ‘switch them off’ depending on previous trauma and stress experience, adds an entirely new dimension to our knowledge of how the brain operates and emotions are formed.”
Professor Pawlak added: “We are now planning to extend our study to investigate if the above mechanisms, or genetic defects of the PAR1 receptor, are responsible for the development of anxiety disorders and depression in human patients. There is more work to be done, but the potential for the development of future therapies based on our findings is both exciting and intriguing.”
The article describing the above findings has recently been published in one of the most prestigious psychiatry journals, Molecular Psychiatry.
(Source: eurekalert.org)