Archive for the ‘post-traumatic stress disorder’ Category

pot

by Jon Hamilton

Veterans who smoke marijuana to cope with post-traumatic stress disorder may be onto something. There’s growing evidence that pot can affect brain circuits involved in PTSD.

Experiments in animals show that tetrahydrocannabinol, the chemical that gives marijuana its feel-good qualities, acts on a system in the brain that is “critical for fear and anxiety modulation,” says Andrew Holmes, a researcher at the National Institute on Alcohol Abuse and Alcoholism. But he and other brain scientists caution that marijuana has serious drawbacks as a potential treatment for PTSD.

The use of marijuana for PTSD has gained national attention in the past few years as thousands of traumatized veterans who fought in Iraq and Afghanistan have asked the federal government to give them access to the drug. Also, Maine and a handful of other states have passed laws giving people with PTSD access to medical marijuana.

But there’s never been a rigorous scientific study to find out whether marijuana actually helps people with PTSD. So lawmakers and veterans groups have relied on anecdotes from people with the disorder and new research on how both pot and PTSD works in the brain.

An Overactive Fear System

When a typical person encounters something scary, the brain’s fear system goes into overdrive, says Dr. Kerry Ressler of Emory University. The heart pounds, muscles tighten. Then, once the danger is past, everything goes back to normal, he says.

But Ressler says that’s not what happens in the brain of someone with PTSD. “One way of thinking about PTSD is an overactivation of the fear system that can’t be inhibited, can’t be normally modulated,” he says.

For decades, researchers have suspected that marijuana might help people with PTSD by quieting an overactive fear system. But they didn’t understand how this might work until 2002, when scientists in Germany published a mouse study showing that the brain uses chemicals called cannabinoids to modulate the fear system, Ressler says.

There are two common sources of cannabinoids. One is the brain itself, which uses the chemicals to regulate a variety of brain cells. The other common source is Cannabis sativa, the marijuana plant.

So in recent years, researchers have done lots of experiments that involved treating traumatized mice with the active ingredient in pot, tetrahydrocannabinol (THC), Ressler says. And in general, he says, the mice who get THC look “less anxious, more calm, you know, many of the things that you might imagine.”

Problems with Pot

Unfortunately, THC’s effect on fear doesn’t seem to last, Ressler says, because prolonged exposure seems to make brain cells less sensitive to the chemical.

Another downside to using marijuana for PTSD is side effects, says Andrew Holmes at the National Institute on Alcohol Abuse and Alcoholism. “You may indeed get a reduction in anxiety,” Holmes says. “But you’re also going to get all of these unwanted effects,” including short-term memory loss, increased appetite and impaired motor skills.

So for several years now, Holmes and other scientists have been testing drugs that appear to work like marijuana, but with fewer drawbacks. Some of the most promising drugs amplify the effect of the brain’s own cannabinoids, which are called endocannabinoids, he says. “What’s encouraging about the effects of these endocannabinoid-acting drugs is that they may allow for long-term reductions in anxiety, in other words weeks if not months.”

The drugs work well in mice, Holmes says. But tests in people are just beginning and will take years to complete. In the meantime, researchers are learning more about how marijuana and THC affect the fear system in people.

At least one team has had success giving a single dose of THC to people during something called extinction therapy. The therapy is designed to teach the brain to stop reacting to something that previously triggered a fearful response.

The team’s study found that people who got THC during the therapy had “long-lasting reductions in anxiety, very similar to what we were seeing in our animal models,” Holmes says. So THC may be most useful when used for a short time in combination with other therapy, he says.

As studies continue to suggest that marijuana can help people with PTSD, it may be unrealistic to expect people with the disorder to wait for something better than marijuana and THC, Ressler says. “I’m a pragmatist,” he says. “I think if there are medications including drugs like marijuana that can be used in the right way, there’s an opportunity there, potentially.”

http://www.npr.org/blogs/health/2013/12/23/256610483/could-pot-help-veterans-with-ptsd-brain-scientists-say-maybe

_67807883_face_research

_67807877_virtualshrink

Ellie is a creation of ICT, and could serve as an important diagnostic and therapeutic tool for veterans with Post-Traumatic Stress Disorder.

By Alastair Leithead
BBC News, Los Angeles

The University of Southern California’s Institute for Creative Technologies is leading the way in creating virtual humans. The result may produce real help for those in need.

The virtual therapist sits in a big armchair, shuffling slightly and blinking naturally, apparently waiting for me to get comfortable in front of the screen.

“Hi, I’m Ellie,” she says. “Thanks for coming in today.”

She laughs when I say I find her a little bit creepy, and then goes straight into questions about where I’m from and where I studied.

“I’m not a therapist, but I’m here to learn about people and would love to learn about you,” she asks. “Is that OK?”

Ellie’s voice is soft and calming, and as her questions grow more and more personal I quickly slip into answering as if there were a real person in the room rather than a computer-generated image.

“How are you at controlling your temper?” she probes. “When did you last get into an argument?”

With every answer I’m being watched and studied in minute detail by a simple gaming sensor and a webcam.

How I smile, which direction I look, the tone of my voice, and my body language are all being precisely recorded and analysed by the computer system, which then tells Ellie how best to interact with me.

“Wizard of Oz mode” is how researcher Louis-Philippe Morency describes this experiment at the University of Southern California’s Institute for Creative Technologies (ICT).

In the next room his team of two are controlling what Ellie says, changing her voice and body language to get the most out of me.

Real people come in to answer Ellie’s questions every day as part of the research, and the computer is gradually learning how to react in every situation.

It is being taught how to be human, and to respond as a doctor would to the patients’ cues.

Soon Ellie will be able to go it alone. That opens up a huge opportunity for remote therapy sessions online using the knowledge of some of the world’s top psychologists.

But Dr Morency doesn’t like the expression “virtual shrink”, and doesn’t think this method will replace flesh-and-blood practitioners.

“We see it more as being an assistant for the clinician in the same way you take a blood sample which is analysed in a lab and the results sent back to the doctor,” he said.

The system is designed to assess signs of depression or post-traumatic stress, particularly useful among soldiers and veterans.

“We’re looking for an emotional response, or perhaps even any lack of emotional response,” he says.

“Now we have an objective way to measure people’s behaviour, so hopefully this can be used for a more precise diagnosis.”

The software allows a doctor to follow a patient’s progress over time. It objectively and scientifically compares sessions.

“The problem we have, particularly with the current crisis in mental health in the military, is that we don’t have enough well trained providers to handle the problem,” says Skip Rizzo, the associate director for medical virtual reality at the ICT.

“This is not a replacement for a live provider, but it might be a stop-gap that helps to direct a person towards the kind of care they might need.”

The centre does a lot of work with the US military, which after long wars in Iraq and Afghanistan has to deal with hundreds of thousands of troops and veterans suffering from various levels of post-traumatic stress disorder.

“We have an issue in the military with stigma and a lot of times people feel hesitant talking about their problems,” he says. A virtual counselling tool can alleviate some of this reluctance.

“We see this as a way for service members or veterans to talk openly and explore their issues.”

The whole lab is running experiments with virtual humans. To do so, it blends a range of technologies and disciplines such as movement sensing and facial recognition.

Dr Morency has won awards for his work into the relationship between psychology and minute physical movements in the face.

“People who are anxious fidget with their hands more, and people who are distressed often have a shorter smile with less intensity. People who are depressed are looking away a lot more,” he says.

Making computer-generated images appear human isn’t easy, but if believable they can be powerful tools for teaching and learning. To that end, the lab is involved in several different projects to test the limits and potential of virtual interactions.

In the lab’s demonstration space a virtual soldier sits behind a desk and responds to a disciplinary scenario as part of officer training.

The team have even built a Wild West style saloon, complete with swinging doors and bar.

Full-size characters appear on three projection screens and interact with a real person walking in, automatically responding to questions and asking their own to play out a fictional scenario.

Downstairs, experiments are creating 3D holograms of a human face.

Throughout the building, the work done is starting to blur the lines between the real world and the virtual world.

And the result just may be real help for humans who need it.

http://www.bbc.co.uk/news/magazine-22630812

Many thanks to Jody, for bringing this to the attention of the It’s Interesting community.

green-image

The flip of a single molecular switch helps create the mature neuronal connections that allow the brain to bridge the gap between adolescent impressionability and adult stability. Now Yale School of Medicine researchers have reversed the process, recreating a youthful brain that facilitated both learning and healing in the adult mouse.

Scientists have long known that the young and old brains are very different. Adolescent brains are more malleable or plastic, which allows them to learn languages more quickly than adults and speeds recovery from brain injuries. The comparative rigidity of the adult brain results in part from the function of a single gene that slows the rapid change in synaptic connections between neurons.

By monitoring the synapses in living mice over weeks and months, Yale researchers have identified the key genetic switch for brain maturation a study released March 6 in the journal Neuron. The Nogo Receptor 1 gene is required to suppress high levels of plasticity in the adolescent brain and create the relatively quiescent levels of plasticity in adulthood. In mice without this gene, juvenile levels of brain plasticity persist throughout adulthood. When researchers blocked the function of this gene in old mice, they reset the old brain to adolescent levels of plasticity.

“These are the molecules the brain needs for the transition from adolescence to adulthood,” said Dr. Stephen Strittmatter. Vincent Coates Professor of Neurology, Professor of Neurobiology and senior author of the paper. “It suggests we can turn back the clock in the adult brain and recover from trauma the way kids recover.”

Rehabilitation after brain injuries like strokes requires that patients re-learn tasks such as moving a hand. Researchers found that adult mice lacking Nogo Receptor recovered from injury as quickly as adolescent mice and mastered new, complex motor tasks more quickly than adults with the receptor.

“This raises the potential that manipulating Nogo Receptor in humans might accelerate and magnify rehabilitation after brain injuries like strokes,” said Feras Akbik, Yale doctoral student who is first author of the study.

Researchers also showed that Nogo Receptor slows loss of memories. Mice without Nogo receptor lost stressful memories more quickly, suggesting that manipulating the receptor could help treat post-traumatic stress disorder.

“We know a lot about the early development of the brain,” Strittmatter said, “But we know amazingly little about what happens in the brain during late adolescence.”

Other Yale authors are: Sarah M. Bhagat, Pujan R. Patel and William B.J. Cafferty

The study was funded by the National Institutes of Health. Strittmatter is scientific founder of Axerion Therapeutics, which is investigating applications of Nogo research to repair spinal cord damage.

http://news.yale.edu/2013/03/06/flip-single-molecular-switch-makes-old-brain-young