Substance Abuse News

Nicotine takes much longer than previously thought to reach peak levels in the brains of cigarette smokers, according to new research conducted at Duke University Medical Center.

Traditionally, scientists thought nicotine inhaled in a puff of cigarette smoke took a mere seven seconds to be taken up by the brain, and that each puff produced a spike of nicotine. Using PET imaging, Duke investigators illustrate, for the first time, that cigarette smokers actually experience a steady rise of brain nicotine levels during the course of smoking a whole cigarette.

The findings, scheduled to appear online in the Early Edition of Proceedings of the National Academy of Sciences (PNAS), could lead to more effective treatments for smoking addiction.

Nicotine Accumulates in the Brain

“Previously it was thought that the puff-by-puff spikes of nicotine reaching the brain explained why cigarettes are so much more addictive than other forms of nicotine delivery, like the patch or gum,” says Jed Rose, Ph.D., director of the Duke Center for Nicotine and Smoking Cessation Research. “Our work now calls into question whether addiction has to do with the puff-by-puff delivery of nicotine. It may actually depend in part on the overall rate at which nicotine reaches and accumulates in the brain, as well as the unique habit and sensory cues associated with smoking.”

Yet, when the researchers compared 13 dependent smokers to 10 non-dependent smokers, they were surprised to find the dependent smokers had a slower rate of nicotine accumulation in the brain. “This slower rate resulted from nicotine staying longer in the lungs of dependent smokers, which may be a result of the chronic effects of smoke on the lungs,” surmises Rose.

The difference in rate of nicotine accumulation in the brain doesn’t explain why some people become addicted to cigarettes and others don’t. “Even if you correct for the speed of delivery, our study showed the non-dependent smokers eventually experienced the same high levels of nicotine in their brain as dependent smokers, yet they did so without becoming dependent. The real mystery is why.”

Sensitivity to Nicotine

Rose says the absence of addiction in these smokers could be due to genetic differences, differences in the way they smoke, or differences in the psychological effects they derive. “We’re still not able to fully explain why these people are able to smoke without becoming addicted.”

Despite the questions raised, the study provides important insights into the role of the speed and level of brain nicotine levels, and which receptors in the brain are at work. “Different receptors respond to nicotine at different levels of sensitivity,” says Rose. “Knowing the levels of nicotine that are really getting to the brain gives us clues as to which receptors are more likely to be important for the dependence-producing effects of cigarette smoking.”

New research by the Oklahoma Tobacco Research Center (OTRC) shows that concentrations of secondhand tobacco smoke inhaled in smoking rooms of restaurants and bars are exceptionally high and hazardous to health.

Hazardous Extremes

According to the study, which appears in the center’s new report “Tobacco Smoke Pollution in Oklahoma Workplaces,” the average particulate level measured in restaurant smoking rooms was beyond the hazardous extreme based on levels established by the U.S. Environmental Protection Agency. The level found in bars was even worse.

“These levels are exceptionally high and not healthy for the employees and patrons exposed to particles found in secondhand smoke,” said Heather Basara, M.D., an industrial hygienist and lead investigator on the research.

Tobacco smoke levels were evaluated based on measurements of very fine suspended particulates in the air, particles smaller than 2.5 microns, which come primarily from tobacco smoke.

Levels averaged 380 µg/m3 (micrograms per cubic meter of air) in the restaurant smoking rooms tested, and 655 µg/m3 in the bars. Restaurants with no smoking averaged just 26 µg/m3.

Very Unhealthy Levels

The EPA scale ranks outdoor levels of particulate pollution as “unhealthy” at 66-150, “very unhealthy”’ at 151-250, and “hazardous” at higher concentrations such as the levels found in the Oklahoma restaurant smoking rooms and bars tested for this report.

Robert McCaffree, M.D., Co-Director of OTRC, said, “Secondhand smoke exposure is a serious health hazard, accounting for approximately 700 deaths a year in Oklahoma, mostly from heart disease – including heart attacks – and lung cancer. Even brief exposure is harmful. Because this exposure is readily preventable, business owners and public policy makers would be well-advised to act as soon as possible to assure smokefree environments for all public places and all indoor workplaces.”

Health authorities should emphasize the positive message that the most successful method used by most ex-smokers is unassisted cessation, despite the promotion of cessation drugs by pharmaceutical companies and many tobacco control advocates.

The dominant messages about smoking cessation contained in most tobacco control campaigns, which emphasize that serious attempts at quitting smoking must be pharmacologically or professionally mediated, are critiqued in an essay in this week’s PLoS Medicine by Simon Chapman and Ross MacKenzie from the School of Public Health at the University of Sydney, Australia.

This overemphasis on quit methods like nicotine replacement therapy (NRT) has led to the “medicalization of smoking cessation,” despite good evidence that the most successful method used by most ex-smokers is quitting “cold turkey” or reducing-then-quitting. Reviewing 511 studies published in 2007 and 2 008 the authors report that studies repeatedly show that two-thirds to three-quarters of ex-smokers stop unaided and most ex-smokers report that cessation was less difficult than expected.

Pharmaceutical Influence

The medicalization of smoking cessation is fuelled by the extent and influence of pharmaceutical support for cessation intervention studies, say the authors. They cite a recent review of randomized controlled trials of nicotine replacement therapy (NRT) that found that 51% of industry-funded trials reported significant cessation effects, while only 22% of non-industry trials did. Many assisted cessation studies—but few if any unassisted cessation studies—involve researchers who declare support from a pharmaceutical company manufacturing cessation products.

The authors conclude that “public sector communicators should be encouraged to redress the overwhelming dominance of assisted cessation in public awareness, so that some balance can restored in smokers’ minds regarding the contribution that assisted and unassisted smoking cessation approaches can make to helping them quit smoking.”

With the national trend toward quitting smoking flat, psychologists are finding some success with treatments aimed at helping smokers from underserved groups, including racial and ethnic minorities and those with psychiatric disorders.

Quit Smoking Help

In the Journal of Consulting and Clinical Psychology, published by the American Psychological Association, researchers report on several effective treatments that may help these smokers in an effort to increase national smoking cessation rates. The percentage of American smokers rose from 19.8 percent in 2007 to 20.6 percent in 2008, after a 10-year steady decline in smoking rates, according to the latest figures from the Centers for Disease Control and Prevention.

“One of the reasons smoking rates have remained stagnant is because these underserved groups of smokers have not been adequately targeted by research and treatment,” said the special section editor, Belinda Borrelli, PhD, who is with the Centers for Behavioral and Preventive Medicine at Brown University Medical School. Underserved smokers include those who have a 10 percent higher smoking rate than the general population, have less access to treatments, and are more likely to be excluded from long-term treatments trials, according to Borelli.

In one article, researchers found that success in stopping smoking differed for different psychiatric disorders. For example, compared to smokers with no psychiatric disorders, smokers who had an anxiety disorder were less likely to quit smoking six months after treatment.

In the same article, researchers found that people’s barriers to quitting were directly related to what type of psychiatric disorder they had. For example, smokers who had ever been diagnosed with an anxiety disorder reported a strong emotional bond with their cigarettes while smokers ever diagnosed with a substance use disorder reported that social and environmental influences were especially likely to affect their smoking. “This information may help clinicians gauge relapse risk and identify treatment targets among smokers who have ever had psychological illnesses,” said lead author Megan Piper, PhD, from the University of Wisconsin School of Medicine and Public Health.

Comparing Treatment

Evidence-based smoking cessation treatments are addressed in another article in this special section. Researchers from the University of Miami looked at the effect of intensive cognitive-behavioral therapy on African-American smokers. They placed 154 African-American smokers wearing nicotine patches into one of two six-session interventions. Participants in the group using cognitive-behavioral techniques were taught relapse prevention strategies and coping skills, along with other techniques. The other group participated in a health education series that explained general medical conditions that are associated with smoking, such as heart disease and lung cancer.

Compared with general health education, participation in cognitive-behavioral therapy sessions more than doubled the rate of quitting at a six month follow-up, from 14 percent to 31 percent the researchers found. “We know cognitive-behavioral therapy helps people quit, but few studies have examined this treatment’s effect on African-American smokers,” said the study’s lead author, Monica Webb, PhD, of the University of Miami. “Hopefully, our findings will encourage smoking cessation counselors and researchers to utilize cognitive-behavioral interventions in this underserved population.”

Secondhand Smoke Study

Borrelli, the section editor, examined another minority group—Latinos. She measured the amount of second-hand smoke in participants’ homes and gave feedback to smokers about how much smoke their child with asthma was exposed to. For example, they were told that their child was exposed to as much smoke as if the child smoked ‘x’ number of cigarettes him- or herself during the week of the measurement – this was the experimental group. Smokers in the control group underwent standard cognitive-behavioral treatment for smoking cessation. Smokers in the experimental group were twice as likely to quit as the control group, Borrelli found. “The child’s asthma problems may provide a teachable moment for parents whereby they become more open to the smoking cessation messages,” Borrelli said. “Providing treatment that is focused on the health needs of the family, and delivered in a culturally tailored manner, has the potential to address health care disparities for Latino families.”

It is common knowledge that smoking is a health risk but why do teens become addicted to smoking more easily than adults? In an evaluation for Faculty of 1000 Biology, Neil Grunberg looks into why adolescents are more prone to substance abuse.

Grunberg describes the study, published by Natividad et al. in Synapse journal, as “fascinating” and suggests it “may have implications to help understand why adolescents are particularly prone to drug abuse”.

Nicotine increases the level of dopamine in the brain, a neurotransmitter that is responsible for feelings of pleasure and wellbeing. The study looked at dopamine levels in adolescent and adult rats after nicotine withdrawal. The authors found that the withdrawal signs (physical and neurochemical) seen in adolescent rats were fewer than those observed in adults.

The study provides previously unknown mechanisms as to why there are differences in nicotine withdrawal between adolescent and adult rats. The key here, as stated by Grunberg, is “age alters [neurological] systems and interactions relevant to nicotine”.

Increased Sensitivity to Drugs

The reason that adolescents are prone to drug abuse (in this case, nicotine) is that they have increased sensitivity to its rewarding effects and do not display the same negative withdrawal effects as adults do, due to an underdeveloped dopamine-producing system.

Since rats are not subject to cultural influences, “rat studies of nicotine … have provided valuable insights that have led to practical behavioural and pharmacological interventions”, says Grunberg.

The results of this study may not stop at nicotine. Grunberg continues, “these findings might also be relevant to other addictive and abuse drugs”.

Public health experts are calling for urgent steps to reduce the number of healthcare professionals who smoke, after a survey of over 800 new nursing students found that more than half were current or former smokers.

The Italian study, published in the January issue of the Journal of Advanced Nursing, surveyed 812 students who were just starting their University course. They found that 44% of them were still smoking – twice as many as in the general population – and a further 12% were former smokers.

Three-quarters of the smoking students had at least one parent who smoked and almost half had at least one brother or sister who smoked.

“Smoking prevention is an important issue and healthcare professionals, especially physicians and nurses, can play a major role in helping people to understand the consequences that smoking can have on their health and their lives” says Professor Anna Maria Tortorano from the Department of Public Health at the University of Milan, Italy.

“However when health professionals smoke it makes it more difficult for them to encourage patients to stop.”

Key findings of the study included:

• 87% of the students agreed to take part in the survey. 63% were female and 85% were native Italians, with the rest coming from developing countries like Peru, Albania and Ecuador.
• The Italian students were much younger than the immigrant students – averaging 23 and 31 respectively for the males and 23 and 28 for the females.
• 39% of the female students and 53% of the male students smoked, giving an overall average of 44%. 37% smoked up to five cigarettes a day and 4% smoked more than 20.
• Students were much more likely to be current or former smokers if their parents smoked. 75% of smokers had a least one smoking parent, compared with 54% of those who had never smoked and 22% came from homes where both parents smoked, compared with 14% of those who had never smoked.
• The smoking habits of the fathers made little difference, with 33% of smokers having just a father who smoked, compared with 31% of non-smokers. However, smokers were twice as likely to have just a mother who smoked (20%) than non-smokers (10%).
• 47% of current and former smokers had siblings who smoked, compared to 25% of those who have never smoked.

“Figures from the World Health Organization show that approximately 35% of men and 22% of women in developed countries are daily smokers, together with 50% of men and 9% of women in developing countries” says Professor Tortorano, who carried out the study with research associate Dr Emanuela Biraghi.

“Figures for the general Italian population show that 22% of people over the age of 14 smoked in 2007.

“However the figure of 44% reported by nursing students who took part in our study is much higher than the 25% observed for medical students at the same University. It is also twice as high as the general Italian population.

“We believe that smoking cessation programmes should be incorporated into nursing studies as high levels of smoking among healthcare professionals undermine the credibility of non-smoking campaigns aimed at the general public.”

An analysis of published studies on the relationship between Alzheimer’s disease and smoking indicates that smoking cigarettes is a significant risk factor for the disease. After controlling for study design, quality of the journals, time of publication, and tobacco industry affiliation of the authors, the UCSF research team also found an association between tobacco industry affiliation and the conclusions of individual studies. Industry-affiliated studies indicated that smoking protects against the development of AD, while independent studies showed that smoking increased the risk of developing the disease.

Study findings were published online in the Journal of Alzheimer’s Disease. An abstract of the paper is available at the link below.

Smoking Not Protective

“For many years, published studies and popular media have perpetuated the myth that smoking is protective against the development of AD. The disease’s impact on quality of life and health care costs continues to rise. It is therefore critical that we better understand its causes, in particular, the role of cigarette smoking,” said Janine K. Cataldo, PhD, RN, assistant professor in the UCSF School of Nursing and lead author of the study.

According to the Alzheimer’s Association, 5.3 million Americans currently have the disease, and that number will escalate rapidly as the baby boom generation ages. AD also triples health care costs for Americans aged 65 and older, the organization states.

The UCSF team reviewed 43 published studies from 1984 to 2007. Authors of one-fourth of the studies had an affiliation with the tobacco industry.

The UCSF team determined that the average risk of a smoker developing AD, based on studies without tobacco industry affiliation, was estimated to be 1.72, meaning that smoking nearly doubled the risk of AD. In contrast, the team found that studies authored by individuals with tobacco industry affiliations, showed a risk factor of .86 (less than one), suggesting that smoking protects against AD. When all studies were considered together, the risk factor for developing AD from smoking was essentially neutral at a statistically insignificant 1.05.

Previous reviews of the association between smoking and AD have not controlled for study design and author affiliation with the tobacco industry, according to Cataldo. To determine if study authors had connections to the tobacco industry, the UCSF team analyzed 877 previously secret tobacco industry documents.

Corrosive Tobacco Research

The researchers used an inclusive definition of “tobacco industry affiliation” and examined authors’ current or past funding, employment, paid consultation, and collaboration or co-authorship on a study with someone who had current or previous tobacco industry funding within 10 years of publication.

“We know that industry-sponsored research is more likely to reach conclusions favorable to the sponsor,” said Stanton A. Glantz, PhD, of the UCSF Department of Medicine and a study co-author. “Our findings point to the ongoing corrosive nature of tobacco industry funding and point to the need for academic institutions to decline tobacco industry funding to protect the research process.”

Judith J. Prochaska, PhD, MPH, of the UCSF Department of Psychiatry, also is a co-author.  The team’s research was supported by grants from the California Tobacco Related Disease Research Program, the National Cancer Institute, and the National Institute on Drug Abuse.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.

Reducing obesity and smoking have become national priorities in the United States. Research has shown that intensive counseling can positively impact each problem. However, because such counseling is typically not covered by medical insurance, cost can be a barrier. In a study published in the March 2010 issue of the American Journal of Preventive Medicine, researchers from Virginia Commonwealth University, Richmond, Virginia, found that when primary care clinicians and community counselors collaborated to offer free counseling services to patients, there was an overwhelming positive response. Yet, when the same services were offered at a cost to the patient, there was a significant drop in participation.

Unhealthy Behavior

An electronic linkage system (eLinkS) was used to prompt healthcare providers to suggest intensive healthcare counseling for adult patients with unhealthy behaviors. eLinkS then helped to facilitate and automate referrals and communication between primary care practices and community programs. During a 5-week period when funding was available, 5679 patients were evaluated, 1860 had at least one unhealthy behavior (triggering an eLinkS prompt), and 407 (21.8%) were referred for intensive counseling.

In a 3-week period after funding was exhausted, 2510 patients visited the practices, 729 triggered an eLinkS prompt, but only 5 (0.7%) were referred for intensive counseling. Compared to the coverage period, the overall referral rate for patients with an unhealthy behavior decreased by 97%. Practice nurses asked 22% fewer patients about health behaviors (37% vs 29%). When prompted by eLinkS, clinicians offered referrals to 79% fewer patients (29% vs 6%). If a referral was offered, 81% fewer patients accepted (76% vs 14%).

Cost Was a Problem

Patients confirmed that costs introduced a barrier to counseling. Some patients were explicit that charges would prevent participation while others who had deferred counseling in the past were motivated to enroll because it was free. Clinicians reported that removing cost as an impediment, combined with an easy means to refer patients, allowed patient discussions to focus on behavior change. The heightened patient interest reversed when charges were reinstituted. Fewer successes also diminished motivation for the counselors.

Alex H. Krist MD, MPH, Virginia Commonwealth University, Department of Family Medicine, and his co-investigators comment, “Our quantitative and qualitative data underscore that clinicians, not just patients, are influenced by costs. Despite prompts, nurses were less likely to record patients’ BMI and smoking status during the no-coverage period, triggering fewer eLinkS prompts. Clinicians were also less likely to discuss health behaviors with patients. However, even when clinicians did offer a referral, 81% fewer patients accepted. …This study indicates that policymakers and payers should support clinical–community partnerships and eliminate cost as a barrier to intensive smoking cessation and weight loss counseling. Modifying health behaviors is daunting enough for patients and clinicians – cost can be the tipping point in their decision to forego the effort.”