Posts tagged smoking
Posts tagged smoking
Treatment for alcohol use disorders works best if the patient actively understands and incorporates the interventions provided in the clinic. Multiple factors can influence both the type and degree of neurocognitive abnormalities found during early abstinence, including chronic cigarette smoking and increasing age. A new study is the first to look at the interactive effects of smoking status and age on neurocognition in treatment-seeking alcohol dependent (AD) individuals. Findings show that AD individuals who currently smoke show more problems with memory, ability to think quickly and efficiently, and problem-solving skills than those who don’t smoke, effects which seem to become exacerbated with age.
Results will be published in the October 2013 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
“Several factors – nutrition, exercise, comorbid medical conditions such as hypertension and diabetes, psychiatric conditions such as depressive disorders and post-traumatic stress disorder, and genetic predispositions – may also influence cognitive functioning during early abstinence,” explained Timothy C. Durazzo, assistant professor in the department of radiology and biomedical imaging at the University of California San Francisco, and corresponding author for the study. “We focused on the effects of chronic cigarette smoking and increasing age on cognition because previous research suggested that each has independent, adverse affects on multiple aspects of cognition and brain biology in people with and without alcohol use disorders. This previous research also indicated that the adverse effects of smoking on the brain accumulate over time. Therefore, we predicted that AD, active chronic smokers would show the greatest decline in cognitive abilities with increasing age.”
“The independent and interactive effects of smoking and other drug use on cognitive functioning among individuals with AD are largely unknown,” added Alecia Dager, associate research scientist in the department of psychiatry at Yale University. “This is problematic because many heavy drinkers also smoke. Furthermore, in treatment programs for alcoholism, the issue of smoking may be largely ignored. This study provides evidence of greater cognitive difficulties in alcoholics who also smoke, which could offer important insights for treatment programs. First, individuals with AD who also smoke may have more difficulty remembering, integrating, and implementing treatment strategies. Second, there are clear benefits for thinking skills as a result of quitting both substances.”
Durazzo and his colleagues compared the neurocognitive functioning of four groups of participants, all between the ages of 26 and 71 years of age: never-smoking healthy individuals or “controls” (n=39); and one-month abstinent, treatment-seeking AD individuals, who were never-smokers (n = 30), former-smokers (n = 21) and active-smokers (n = 68). Evaluated cognitive abilities included cognitive efficiency, executive functions, fine motor skills, general intelligence, learning and memory, processing speed, visuospatial functions, and working memory.
“We found that, at one month of abstinence, actively smoking AD [individuals] had greater-than-normal age effects on measures of learning, memory, processing speed, reasoning and problem-solving, and fine motor skills,” said Durazzo. “AD never-smokers and former-smokers showed equivalent changes on all measures with increasing age as the never-smoking controls. These results indicate the combination of alcohol dependence and active chronic smoking was related to an abnormal decline in multiple cognitive functions with increasing age.”
“These results indicate the combined effects of these drugs are especially harmful and become even more apparent in older age,” said Dager. “In general, people show cognitive decline in older age. However, it seems that years of combined alcohol and cigarette use exacerbate this process, contributing to an even greater decline in thinking skills in later years.”
Durazzo agreed. “Chronic cigarette smoking, excessive alcohol consumption, and increasing age are all associated with increased oxidative damage to brain tissue,” he said. “Oxidative damage results from increased levels of free radicals and other compounds that directly injure neurons and other cells that make up the brain. Cigarette smoking and excessive alcohol consumption expose the brain to a tremendous amount of free radicals. We hypothesize that chronic, long-term exposure to cigarette smoke and excessive alcohol consumption interacts with the normal aging process to produce greater neurocognitive decline in the active-smoking AD group.”
Cigarette smoking is a “modifiable health risk” that is directly associated with at least 440,000 deaths every year in the United States, Durazzo noted. “Chronic smoking, and to a lesser extent, alcohol use disorders are also associated with an increased risk for Alzheimer’s disease,” he said. “So, the combination of these modifiable health risks may place an individual at even greater risk for development of Alzheimer’s disease. Given the above, in conjunction with the findings from our cognitive and neuroimaging research, we completely support programs that routinely offer smoking cessation programs to all individuals seeking treatment for alcohol/substance abuse disorders.”
Cigarette smoking is the leading cause of preventable deaths globally. Unfortunately smoking cessation is difficult, with more than 90% of attempts to quit resulting in relapse.
There are a growing number of available methods that can be tried in the effort to reduce smoking, including medications, behavioral therapies, hypnosis, and even acupuncture. All attempt to alter brain function or behavior in some way.
A new study published in Biological Psychiatry now reports that a single 15-minute session of high frequency transcranial magnetic stimulation (TMS) over the prefrontal cortex temporarily reduced cue-induced smoking craving in nicotine-dependent individuals.
Nicotine activates the dopamine system and reward-related regions in the brain. Nicotine withdrawal naturally results in decreased activity of these regions, which has been closely associated with craving, relapse, and continued nicotine consumption.
One of the critical reward-related regions is the dorsolateral prefrontal cortex, which can be targeted using a brain stimulation technology called transcranial magnetic stimulation. Transcranial magnetic stimulation is a non-invasive procedure that uses magnetic fields to stimulate nerve cells. It does not require sedation or anesthesia and so patients remain awake, reclined in a chair, while treatment is administered through coils placed near the forehead.
Dr. Xingbao Li and colleagues at Medical University of South Carolina examined cravings triggered by smoking cues in 16 nicotine-dependent volunteers who received one session each of high frequency or sham repetitive transcranial magnetic stimulation applied over the dorsolateral prefrontal cortex. This design allowed the researchers to ferret out the effects of the real versus the sham stimulation, similar to how placebo pills are used in evaluating the effectiveness and safety of new medications.
They found that craving induced by smoking cues was reduced after participants received real stimulation. They also report that the reduction in cue-induced craving was positively correlated with level of nicotine dependence; in other words, the TMS-induced craving reductions were greater in those with higher levels of nicotine use.
Dr. John Krystal, Editor of Biological Psychiatry, commented, “One of the elegant aspects of this study is that it suggests that specific manipulations of particular brain circuits may help to protect smokers and possibly people with other addictions from relapsing.”
“While this was only a temporary effect, it raises the possibility that repeated TMS sessions might ultimately be used to help smokers quit smoking. TMS as used in this study is safe and is already FDA approved for treating depression. This finding opens the way for further exploration of the use of brain stimulation techniques in smoking cessation treatment,” said Li.
Your DNA may play a significant role in determining whether or not you end up a smoker – and how easy you find it to kick the habit.
Many large studies have identified particular gene variants that are more common in smokers than other people, suggesting the they play a role in nicotine dependence.
Now an international team of researchers have used these genetic clues develop a ‘genetic risk profile’, and to see how accurate it is, they have road-tested it on the on a well known sample of Kiwis: the Dunedin Birth Cohort.
Researchers analysed data from the long-term study of 1,000 New Zealanders to identify whether individuals at high genetic risk got hooked on cigarettes more quickly as teens and whether, as adults, they had a harder time quitting.
The results, published in JAMA Psychiatry, showed that a person’s genetic risk profile did not predict whether he or she would try cigarettes. But for those who did try cigarettes, having a high-risk genetic profile predicted increased likelihood of heavy smoking and nicotine dependence.
This link was most apparent for teenagers; Among teens who tried cigarettes, those with a high-risk genetic profile were 24 percent more likely to become daily smokers by age 15 and 43 percent more likely to become pack-a-day smokers by age 18.
As adults, those with high-risk genetic profiles were 22 percent more likely to fail in their attempts at quitting.
“The effects of genetic risk seem to be limited to people who start smoking as teens,” said author Daniel Belsky, a post-doctoral research fellow at Duke University.
“This suggests there may be something special about nicotine exposure in the adolescent brain, with respect to these genetic variants.”
The authors noted that their genetic risk profile isn’t yet accurate enough to be used for targeted interventions to prevent at-risk teens smoking, but it does highlight the critical adolescent period in addiction development.
“Public health policies that make it harder for teens to become regular smokers should continue to be a focus in antismoking efforts,” Belsky said.
Smoking “rots” the brain by damaging memory, learning and reasoning, according to researchers at King’s College London. A study of 8,800 people over 50 showed high blood pressure and being overweight also seemed to affect the brain, but to a lesser extent.
Scientists involved said people needed to be aware that lifestyles could damage the mind as well as the body. Their study was published in the journal Age and Ageing.
Researchers at King’s were investigating links between the likelihood of a heart attack or stroke and the state of the brain. Data about the health and lifestyle of a group of over-50s was collected and brain tests, such as making participants learn new words or name as many animals as they could in a minute, were also performed.
They were all tested again after four and then eight years. The results showed that the overall risk of a heart attack or stroke was “significantly associated with cognitive decline” with those at the highest risk showing the greatest decline.
It also said there was a “consistent association” between smoking and lower scores in the tests. One of the researchers, Dr Alex Dregan, said: “Cognitive decline becomes more common with ageing and for an increasing number of people interferes with daily functioning and well-being.
“We have identified a number of risk factors which could be associated with accelerated cognitive decline, all of which, could be modifiable.” He added: “We need to make people aware of the need to do some lifestyle changes because of the risk of cognitive decline.”
The researchers do not know how such a decline could affect people going about their daily life. They are also unsure whether the early drop in brain function could lead to conditions such as dementia.
Preclinical data suggests inactivation of a specific sub-class of nicotinic receptors may be an effective strategy to help smokers quit without feeling anxious, according to Virginia Commonwealth University researchers.
These findings could one day point researchers to the development of novel therapies to help smokers quit without feeling anxious.
Smokers use cigarettes for many reasons, but many report that they smoke to relieve anxiety, despite the health danger of cigarette smoking. Researchers are now working to understand the underlying neurochemical pathways that support smoking behavior.
In a study, published online this week in PLoS ONE, researchers observed that low doses of nicotine and a nicotinic receptor blocker had similar effects to reduce anxiety-like behavior in an animal model. They found that inactivation of beta2 subunit, a specific sub-class of nicotinic receptors that bind nicotine, appears to reduce anxiety. This is different from the mechanism that regulates nicotine reward and likely occurs in a separate brain area.
“This work is unique because it suggests that nicotine may be acting through inactivation, rather than activation, of the high affinity nicotinic receptors,” said Darlene Brunzell, Ph.D., assistant professor in the Department of Pharmacology and Toxicology in the VCU School of Medicine.
“Nicotine acts like a key that unlocks nicotine receptors in the brain. Usually that key opens the receptor, but at other times nicotine is like a key that has gotten broken inside of the lock. Our findings suggest that low-dose nicotine may block a specific subtype of receptor from opening that is important for regulating anxiety behavior,” she said, adding that anxiety is a major reason why people relapse to smoking.
Smoking and hyperactivity (ADHD) share common genetic risk factor
A variation of a particular gene may link the behaviours typical of childhood attention hyperactivity disorder, or ADHD for short, and those associated with smoking, suggests research published online in the Archives of Disease in Childhood (1, 2)
Childhood ADHD and subsequent smoking in adulthood frequently go hand in hand, say the authors, with people who have been diagnosed with ADHD more likely to start smoking early and to smoke twice as much as those without the condition.
The researchers focused on five variations in DNA sequences (single nucleotide polymorphisms or SNPs) in different genes that are strongly associated with different aspects of smoking behaviour, such as the number of cigarettes smoked every day, and taking up and quitting smoking.
Cigarettes have already been linked to a plethora of different diseases and adverse health conditions, and now a new study has found that the smoking could also increase the risk of developing cataracts in some individuals.
Dr. Juan Ye of the Zhejiang University Institute of Ophthalmology and colleagues conducted a meta-analysis, reviewing a dozen cohorts and eight case-control studies from five continents (Africa, Asia, Australia, Europe and North America) to determine smoking’s impact on the development of age-related cataracts, the leading cause of vision loss and blindness in the world.
They looked at the occurrence of age-related cataract in individuals who had smoked cigarettes versus those who had never lit up. They also looked at the differences between former and current smokers, as well as each of the three different types of cataract that can develop in older individuals, the Association for Research and Vision in Ophthalmology (ARVO) explained in an October 12 press release.
“The results showed that every individual that ever smoked cigarettes was associated with an increased risk of age-related cataract, with a higher risk of incidence in current smokers,” they said, adding that “former and current smokers showed a positive association with two of the subtypes: nuclear cataract, when the clouding is in the central nucleus of the eye, and subscapular cataract, when the clouding is in the rear of the lens capsule.”
The study did not find a link between smoking and cortical cataract, a type of cataract in which the cortex of the lens is affected by cloudiness. Their findings have been published in the journal Investigative Ophthalmology & Visual Science (IOVS).
“Although cataracts can be removed surgically to restore sight, many people remain blind from cataracts due to inadequate surgical services and high surgery expenses,” Ye said. “Identifying modifiable risk factors for cataracts may help establish preventive measures and reduce the financial as well as clinical burden caused by the disease.”
“We think our analysis may inspire more high-quality epidemiological studies” the study author added. “Our analysis shows that association between smoking and the risk of age-related cataract differ by subtypes, suggesting that pathophysiologic processes may differ in the different cataract types.”
Non-smokers who live with or spend time with smokers are damaging their memory, according to new research from Northumbria University.
The findings, published in the latest online edition of the journal Addiction is the first study to explore the relationship between exposure to other people’s smoke and everyday memory problems.
Dr Tom Heffernan and Dr Terence O’Neil, both researchers at the Collaboration for Drug and Alcohol Research Group at Northumbria University, compared a group of current smokers with two groups of non-smokers – those who were regularly exposed to second-hand smoke and those who were not.
Those exposed to second-hand smoke either lived with smokers or spent time with smokers, for example in a designated “smoking area,” and reported being exposed to second-hand smoke for an average of 25 hours a week for an average of four and a half years.
The three groups were tested on time-based memory (remembering to carry out an activity after some time) and event-based memory (which refers to memory for future intentions and activities).
Researchers found that the non-smokers who had been exposed to second-hand smoke forgot almost 20% more in the memory tests than those non-smokers not exposed. However, both groups out-performed the current smokers who forgot 30% more than those who were not exposed to second-hand smoking.
Dr Heffernan said: “According to recent reports by the World Health Organisation, exposure to second-hand smoke can have serious consequences on the health of people who have never smoked themselves, but who are exposed to other people’s tobacco smoke.
“Our findings suggest that the deficits associated with second-hand smoke exposure extend to everyday cognitive function. We hope our work will stimulate further research in the field in order to gain a better understanding of the links between exposure to second-hand smoke, health problems and everyday cognitive function.”
Have you ever wondered why some people find it so much easier to stop smoking than others?
New research shows that vulnerability to smoking addiction is shaped by our genes. A study from the Montreal Neurological Institute and Hospital - The Neuro, McGill University shows that people with genetically fast nicotine metabolism have a significantly greater brain response to smoking cues than those with slow nicotine metabolism. Previous research shows that greater reactivity to smoking cues predicts decreased success at smoking cessation and that environmental cues promote increased nicotine intake in animals and humans. This new finding that nicotine metabolism rates affect the brain’s response to smoking may lead the way for tailoring smoking cessation programs based on individual genetics.
June 27, 2012
Smoking, head injury, pesticide exposure, farming and less education may be risk factors for a rare sleep disorder that causes people to kick or punch during sleep, according to a study published in the June 27, 2012, online issue of Neurology, the medical journal of the American Academy of Neurology.
People with the disorder, called REM sleep behavior disorder, do not have the normal lack of muscle tone that occurs during rapid eye movement (REM) sleep, causing them to act out their dreams. The movements can sometimes be violent, causing injury to the person or their bed partner. The disorder is estimated to occur in 0.5 percent of adults.
“Until now, we didn’t know much about the risk factors for this disorder, except that it was more common in men and in older people,” said study author Ronald B. Postuma, MD, MSc, with the Research Institute of the McGill University Health Centre (MUHC) in Montreal and a member of the American Academy of Neurology. “Because it is a rare disorder, it was difficult to gather information about enough patients for a full study. For this study, we worked with 13 institutions in 10 countries to get a full picture of the disorder.”
The disorder can also be a precursor to neurodegenerative diseases such as Parkinson’s disease and a type of dementia. Studies have shown that more than 50 percent of people with REM sleep behavior disorder go on to develop a neurodegenerative disorder years or even decades later.
“Due to this connection, we wanted to investigate whether the risk factors for REM sleep behavior disorder were similar to those for Parkinson’s disease or dementia,” Postuma said.
The results were mixed. While smoking has found to be a protective factor for Parkinson’s disease, people who smoked were found to be more likely to develop REM sleep behavior disorder. Pesticide use, on the other hand, is a risk factor for both disorders. Studies have shown that people who drink coffee are less likely to develop Parkinson’s, but this study found no relationship between coffee drinking and REM sleep behavior disorder.
For the study, 347 people with REM sleep behavior disorder were compared to 347 people who did not have the disorder. Of those, 218 had other sleep disorders and 129 had no sleep disorders.
Those with REM sleep behavior disorder were 43 percent more likely to be smokers, with 64 percent of those with the disorder having ever smoked, compared to 56 percent of those without the disorder. They were 59 percent more likely to have had a previous head injury with loss of consciousness, 67 percent more likely to have worked as farmers, and more than twice as likely to have been exposed to pesticides through work. Those with the disorder also had fewer years of education, with an average of 11.1 years, compared to 12.7 years for those without the disorder.
More information: To learn more about sleep disorders, visit http://www.aan.com/patients
Provided by American Academy of Neurology