Tuesday, 17 January 2012
A human's ability to remember data, to reason, and understand things properly can start to worsen at the age of 45 years, and not 60 as many had believed, researchers from France and the United Kingdom reported in the BMJ (British Medical Journal). According to prior studies, cognitive decline, if it does occur, will generally not do so before the age of sixty. Many experts had wondered whether the deterioration might not start sooner.
Study leader, Archana Singh-Manoux, at the Centre for Research in Epidemiology and Population Health, France, and researchers from University College London in the UK, believe that..:
"..understanding cognitive aging will be one
of the challenges of this century."
The authors stress that identifying cognitive decline onset is crucial for effective medical interventions. In other words, the earlier-on cognitive deterioration can be spotted, the better medical treatments tend to be.
Singh-Manoux and team observed 2,192 females and 5,198 males from 1997 to 2007. All the subjects were civil servants aged from forty-five to seventy years - they formed part of the Whitehall II cohort study (a UK study), which had started in 1985.
Over the ten-year period, all study-participants had their cognitive functions assessed. This included testing for:
* Aural comprehension skills (listening skills)
* Visual comprehension skills. The journal cites as examples, remembering as many words as possible that started with the letter "S" (phonemic fluency), or recalling as many animal names as possible (semantic fluency).
Factors which might impact on their findings were taken into account, such as the participant's level of education.
They found that cognitive scores dropped in all categories, except for vocabulary. The older the participant, the faster their decline was likely to be.
From 1997 to 2007, mental reasoning among the males aged 45-49 dropped by 3.6%, and 9.6% in the 65-70 age group (males). Among females, the decline was 3.6% for those aged 45-49, and 7.4% among those aged 65-70.
The authors wrote:
"Robust evidence showing cognitive decline before the age of 60 has important ramifications because it demonstrates the importance of promoting healthy lifestyles, particularly cardiovascular health, as there is emerging evidence that 'what is good for our hearts is also good for our heads'."
There are certain risk factors linked to cognitive decline, such as hypertension, obesity, and high cholesterol levels. Targeting patients with known risk factors might not only protect their hearts, but also prevent dementia from developing later on.
In the same journal, Francine Grodstein, Associate Professor of Medicine at Brigham and Women's Hospital in Boston, wrote:
"(The study) has profound implications for prevention of dementia
and public health."
Grodstein believes more creative research is required, using computer cognitive assessments and telephone assessments.
Written by Christian Nordqvist
Copyright: Medical News Today
Wednesday, 20 October 2010
August 26, 2004 | Seattle Weekly - Alternet by Philip Dawdy
Can reefers cure madness? There is some evidence that cannabis – or 'green Prozac' – has potential in the treatment of some psychiatric disorders, principally depression and bipolar disorder.
Smoking marijuana, the federal government constantly reminds us, is dangerous in every way. It impairs cognitive functioning, makes you high, and, because it's smoked, is a demon in a bong hit – and so on.
A counterargument is that pot has helped thousands of cancer and AIDS patients, for example, contend with side effects of their illnesses and treatments. There is also evidence that marijuana works for some psychiatric disorders as well, principally depression and bipolar disorder. Among some people, pot is jokingly referred to as "green Prozac."
The problem is you can't legally take a toke for psychiatric diagnoses.
"I think cannabis has a lot of potential in the treatment of mental illness," says Lester Grinspoon, emeritus professor of psychiatry at the Harvard School of Medicine. He says that it can be an effective treatment for bipolar disorder and depression. Like any medicine, he cautions, it won't work for everyone. Grinspoon has, over the last three decades, been one of the few psychiatrists willing to speak publicly on mental marijuana.
Most of the evidence to support use of pot as medicine is anecdotal; i.e., it seems to help AIDS and cancer patients contend with their diseases and handle the nausea they often experience from treatment, so there must be something to it. Many people also report that it provides a quick lift from the bowels of depression.
My own anecdotal, ahem, experience is that pot does indeed boost my mood from the badlands of depression and lower me from the Mount Everests of mania. I have no idea why or how, nor do I especially care – I'm one of those people who find Prozac and its progeny to be barely effective and with enough nasty side effects to outweigh the benefits. But I'll never tell that to the Drug Enforcement Administration or drug czar John Walters.
Instead, I'll let the Israeli army speak for me. Two weeks ago, it announced that it would provide, on an experimental basis, medical marijuana to troops suffering from post-traumatic stress disorder, another mental illness. Good enough for an army, good enough for me.
But in states with medical marijuana laws, each attempt to get depression or bipolar disorder added to the list of ailments for which the kine can be oh-so-kind has been shot down.
For example, four years ago, the Washington Medical Quality Assurance Commission was petitioned to add mental illness to its list of approved uses of medical marijuana. The commission denied the request. It argued that there was no lock-solid scientific evidence that weed worked for mental illness. The odd thing is that it had approved pot for treatment of Alzheimer's, Krohn's disease, chronic pain, and wasting syndrome based upon – you guessed it – anecdotal evidence.
The feds would like to keep any evidence that reefer is an Rx anecdotal – no peer-reviewed, double-blind studies here – as it bolsters their case that there's no scientific proof that pot works for anything except getting people high. It's the evil weed.
As proof, the DEA touts the following from a 1999 scientific report: It states that " . . . there is little future in smoked marijuana as a medically approved medication."
The report was prepared by the Institute of Medicine (IOM), part of the independent National Academies of Science. Interestingly, the feds lifted that quote from deep in the report. But perhaps more telling is that only one sentence later, the report says: "The personal medical use of smoked marijuana – regardless of whether or not it is approved – to treat certain symptoms is reason enough to advocate clinical trials to assess the degree to which the symptoms or course of diseases are affected."
The IOM backed that up with several strong recommendations that medical marijuana should be thoroughly studied – you know, like scientists study every other treatment under the sun.
To date, that hasn't happened.
"Who is going to get approval from an institutional review board to break the law?" asks Grinspoon. Researchers must have their studies cleared by such boards before they can do experiments with humans. He likens the situation to that of lithium. Its efficacy for treating mental illness was found by accident in the 1940s by an Australian scientist. The evidence was anecdotal. It wasn't until the late 1950s that the feds allowed it to be used in this country, despite the fact that it was saving lives on the other side of the globe.
That's not to say that marijuana is the new lithium or an all-conquering antidepressant. This is not an argument for 40 grams to freedom. Most psych meds work quite well for an estimated 60 percent to 70 percent of patients. It's the remaining 30 percent to 40 percent who are in a sketchier situation. If the approved meds don't work at all or barely work their alleged magic, where are you supposed to turn?
Psychiatrists usually prescribe another med such as Lexapro, a new antidepressant that's all the rage these days. Personally, I found that marijuana had a positive effect quite by accident, especially when dealing with short-lived psychoses. Medications for that typically take hours or days to work – and when you are in that state, you aren't interested in anything but relief by any means necessary, stat.
So let's assume that weed works for a minority of the mentally ill. Doctors usually come back with the assertion that pot has too many side effects, such as respiratory ailments, to even consider its use. I wonder what universe they live in. Long-term use of psych meds themselves carries a host of side effects, which have been poorly evaluated in long-term studies – kidney and liver damage chief among them, along with nausea, weight gain, sexual dysfunction, sleep interference, and hair loss. And they talk about the side effects of marijuana? By comparison, pot's side effects are almost minimal. So, I'll take that medical marijuana any day – I'd simply like to do it legally.
Friday, 20 August 2010
It's unavoidable: breakdowns in brain connections slow down our physical response times as we age, a new study suggests.
This slower reactivity is associated with an age-related breakdown in the corpus callosum, a part of the brain that acts as a dam during one-sided motor activities to prevent unwanted connectivity, or cross-talk, between the two halves of the brain, said Rachael Seidler, associate professor in the University of Michigan School of Kinesiology and Department of Psychology, and lead study author.
At other times the corpus callosum acts at a bridge and cross-talk is helpful, such as in certain cognitive functions or two-sided motor skills.
The U-M study is the first known to show that this cross-talk happens even while older adults are at rest, said Seidler, who also has appointments in the Institute of Gerontology and the Neuroscience Graduate Program. This resting cross-talk suggests that it is not helpful or compensatory for the two halves of the brain to communicate during one-sided motor movements because the opposite side of the brain controls the part of the body that is moving. So, when both sides of the brain talk simultaneously while one side of the body tries to move, confusion and slower responses result, Seidler said.
Previous studies have shown that cross-talk in the brain during certain motor tasks increases with age but it wasn't clear if that cross-talk helped or hindered brain function, said Seidler.
"Cross-talk is not a function of task difficulty, because we see these changes in the brain when people are not moving," Seidler said.
In some diseases where the corpus callosum is very deteriorated, such as in people with multiple sclerosis, you can see "mirror movements" during one sided-motor tasks, where both sides move in concert because there is so much communication between the two hemispheres of the brain, Seidler said. These mirror movements also happen normally in very young children before the corpus callosum is fully developed.
In the study, researchers gave joysticks to adults between the ages of 65 and 75 and measured and compared their response times against a group approximately 20-25 years old.
Researchers then used a functional MRI to image the blood-oxygen levels in different parts of the brain, a measurement of brain activity.
"The more they recruited the other side of the brain, the slower they responded," Seidler said.
However there is hope, and just because we inevitably age doesn't mean it's our fate to react more slowly. Seidler's group is working on developing and piloting motor training studies that might rebuild or maintain the corpus callosum to limit overflow between hemispheres, she said.
A previous study done by another group showed that doing aerobic training for three months helped to rebuild the corpus callosum, she said, which suggests that physical activity can help to counteract the effects of the age-related degeneration.
Seidler's group also has a study in review that uses the same brain imaging techniques to examine disease related brain changes in Parkinson's patients.
University of Michigan