1. How do close relationships lead to longer life?

    September 19, 2017 by Ashley

    From the American Psychological Association press release:

    While recent research has shown that loneliness can play a role in early death, psychologists are also concerned with the mechanisms by which social relationships and close personal ties affect health. A special issue of American Psychologist, the flagship journal of the American Psychological Association, offers an overview of the science and makes the case for psychological scientists to work together to make close relationships a public health priority.

    “The articles in this special issue represent state-of-the-art work on the central issues in the study of close relationships and health. They draw from relationship science and health psychology, two areas of scientific inquiry with independent histories and distinct domains,” special issue editor Christine Dunkel Schetter, PhD, wrote in the introduction. “The goal of this special issue is to bridge the gap between these two specialties to improve the quality and usefulness of future research and practice.”

    Articles focus on topics including how healthy relationships early in life affect physical and mental health in childhood and beyond; the role of intimate relationships in coronary heart disease; the need to focus on partners when treating someone with chronic disease; and the increasingly complex biological pathways involved linking relationships to health.

    “The challenge remains to translate existing and future knowledge into interventions to improve social relationships for the benefit of physical and mental health,” wrote Dunkel Schetter, of the University of California, Los Angeles.


  2. Study suggests yoga, meditation improve brain function and energy levels

    September 18, 2017 by Ashley

    From the University of Waterloo press release:

    Practicing brief sessions of Hatha yoga and mindfulness meditation can significantly improve brain function and energy levels, according to a new study from the University of Waterloo.

    The study found that practicing just 25 minutes of Hatha yoga or mindfulness meditation per day can boost the brain’s executive functions, cognitive abilities linked to goal-directed behavior and the ability to control knee-jerk emotional responses, habitual thinking patterns and actions.

    “Hatha yoga and mindfulness meditation both focus the brain’s conscious processing power on a limited number of targets like breathing and posing, and also reduce processing of nonessential information,” said Peter Hall, associate professor in the School of Public Health & Health Systems. “These two functions might have some positive carryover effect in the near- term following the session, such that people are able to focus more easily on what they choose to attend to in everyday life.”

    Thirty-one study participants completed 25 minutes of Hatha yoga, 25 minutes of mindfulness meditation, and 25 minutes of quiet reading (a control task) in randomized order. Following both the yoga and meditation activities, participants performed significantly better on executive function tasks compared to the reading task.

    “This finding suggests that there may be something special about meditation — as opposed to the physical posing — that carries a lot of the cognitive benefits of yoga,” said Kimberley Luu, lead author on the paper.

    The study also found that mindfulness meditation and Hatha yoga were both effective for improving energy levels, but Hatha yoga had significantly more powerful effects than meditation alone.

    “There are a number of theories about why physical exercises like yoga improve energy levels and cognitive test performance,” said Luu. “These include the release of endorphins, increased blood flow to the brain, and reduced focus on ruminative thoughts. Though ultimately, it is still an open question.”

    Hatha yoga is one of the most common styles of yoga practiced in Western countries.

    It involves physical postures and breathing exercises combined with meditation. Mindfulness mediation involves observing thoughts, emotions and body sensations with openness and acceptance.

    Although the meditative aspect might be even more important than the physical posing for improving executive functions, there are additional benefits to Hatha yoga including improvements in flexibility and strength,” said Hall. “These benefits may make Hatha yoga superior to meditation alone, in terms of overall health benefits.”


  3. Study suggests cultural context may affect link between positive emotions and health

    September 14, 2017 by Ashley

    From the Association for Psychological Science press release:

    Positive emotions are often seen as critical aspects of healthy living, but new research suggests that the link between emotion and health outcomes may vary by cultural context. The findings, published in Psychological Science, a journal of the Association for Psychological Science, show that experiencing positive emotions is linked with better cardiovascular health in the US but not in Japan.

    “Our key finding is that positive emotions predict blood-lipid profiles differently across cultures,” says psychological scientist Jiah Yoo of the University of Wisconsin-Madison. “American adults who experience high levels of positive emotions, such as feeling ‘cheerful’ and ‘extremely happy’, are more likely to have healthy blood-lipid profiles, even after accounting for other factors such as age, gender, socioeconomic status, and chronic conditions. However, this was not true for Japanese adults.”

    “Our findings underscore the importance of cultural context for understanding links between emotion and health, something that has been largely ignored in the literature,” Yoo adds. “Although some studies have examined cultural differences in links between positive emotions and healthy functioning, this work is novel in that it includes biological measures of health and large representative samples from both countries.”

    The fact that positive emotions are conceived of and valued differently across cultures led Yoo and colleagues to wonder whether the health benefits observed in tandem with positive emotions might be specific to Western populations.

    In American cultures, experiencing positive emotions is seen as desirable and is even encouraged via socialization. But in East Asian cultures, people commonly view positive emotions as having dark sides — they are fleeting, may attract unnecessary attention from others, and can be a distraction from focusing on important tasks,” says Yoo.

    The researchers designed a cross-cultural comparison, examining data from two large representative studies of adults: Midlife in the United States and Midlife in Japan, both funded by the National Institute on Aging. Data included participants’ ratings of how frequently they felt 10 different positive emotions in the previous 30 days and measures of blood lipids, which provided objective data on participants’ heart health.

    “Because of the global prevalence of coronary artery disease, blood lipids are considered important indices of biological health in many Western and East Asian countries,” Yoo explains.

    As expected, the data indicated that experiencing frequent positive emotions was associated with healthy lipid profiles for American participants. But there was no evidence of such a link for Japanese participants.

    The differences may be due, in part, to the relationships between positive emotions and BMI in each culture. Higher positive emotions were linked with lower BMI and, in turn, healthier lipid profiles among American participants, but not among Japanese participants.

    “By demonstrating that the cultural variation in the connection between emotional well-being and physical well-being, our research has wide-ranging relevance among those who seek to promote well-being in the communities and the workplace, including clinicians, executives, and policy makers,” Yoo concludes.

    In future work, the researchers will examine longitudinal data to determine whether the evidence suggests a direct causal link between emotions and health. They also hope to identify emotional profiles that may be more relevant or important to health outcomes in East Asian cultures.


  4. Brain changes linked to physical, mental health in functional neurological disorder

    September 13, 2017 by Ashley

    From the Massachusetts General Hospital press release:

    An imaging study by Massachusetts General Hospital (MGH) investigators has identified differences in key brain structures of individuals whose physical or mental health has been most seriously impaired by a common but poorly understood condition called functional neurological disorder (FND). In their report published online in the Journal of Neurology, Neurosurgery and Psychiatry, the research team describes reductions in the size of a portion of the insula in FND patients with the most severe physical symptoms and relative volume increases in the amygdala among those most affected by mental health symptoms.

    “The brain regions implicated in this structural neuroimaging study are areas involved in the integration of emotion processing, sensory-motor and cognitive functions, which may help us understand why patients with functional neurological disorder exhibit such a mix of symptoms,” says David Perez, MD, MMSc, of the MGH Departments of Neurology and Psychiatry, lead and corresponding author of the report. “While this is a treatable condition, many patients remain symptomatic for years, and the prognosis varies from patient to patient. Advancing our understanding the pathophysiology of FND is the first step in beginning to develop better treatments.”

    One of the most common conditions bringing patients to neurologists, FND involves a constellation of neurologic symptoms — including weakness, tremors, walking difficulties, convulsions, pain and fatigue — not explained by traditional neurologic diagnoses. This condition has also been called conversion disorder, reflecting one theory that patients were converting emotional distress into physical symptoms, but Perez notes that this now appears to be an oversimplified view of a complex neuropsychiatric condition. The research team hopes that advancing the neurobiological understanding of FND will increase awareness and decrease the stigma — including skepticism about the reality of patients’ symptoms — often associated with this condition.

    Previous functional MRI studies have suggested that a group of brain structures forming part of what is called the salience network — which are involved in detecting important bodily and environmental stimuli, as well as integrating emotional, cognitive and sensory-motor experiences — showed increased activity in FND patients during a variety of behavioral and emotion-processing tasks. The current study is one of the first to examine structural relationships between components of the salience network and the physical and mental health of patients with FND.

    The researchers compared whole-brain structural MRI scans of 26 FND patients with those of 27 healthy control participants, looking for associations between the size of salience-network structures and participants’ reports of their physical health, mental health and symptoms of anxiety and depression. While there were no whole-brain structural differences between FND patients and healthy controls, patients reporting the greatest levels of physical impairment were found to have decreased volume in the left anterior insula, while those reporting the greatest mental health impairments and highest anxiety levels had increased volume within the amygdala.

    “The association among FND patients between the severity of impairments in physical functioning and reduced left anterior insular volume is intriguing, given that the anterior insula has been implicated in self- and emotional awareness,” says Perez, who is a dual trained neurologist-psychiatrist and an assistant professor of Neurology at Harvard Medical School.

    He adds, “Little attention has been given to FND to date, which is striking given its prevalence and the health care expenses driven by patients suffering with FND. I hope that advancing the neurobiological understanding of FND will help decrease the stigma often associated with this condition and increase public awareness of the unmet needs of this patient population.”


  5. Psychologists examine how to package health recommendations

    September 10, 2017 by Ashley

    From the University of Illinois College of Liberal Arts & Sciences press release:

    In the world of health care, the phrase “too much information” — or TMI — can be a serious problem. If you Google “How to prevent cancer,” for example, you will find list after list of websites claiming to have the winning strategy, with some plans presenting 20-30 steps.

    The same situation occurs if one searches for information on quitting smoking, exercising, sleep, and endless other issues. The question becomes this: When does a person receive too much health information? What’s the best way for health providers to convey information without consumers skipping over or forgetting key information?

    According to a new study from the University of Illinois, the answer lies in the goal of a specific health objective. Dolores Albarracin, professor of psychology, graduate student Jack McDonald, and colleagues at other universities studied the behavior of some 459 people to shine light on this topic that challenges health providers.

    One school of thought among health care providers is to give health information in small doses of two or three recommendations at once. Others argue that it’s best to give patients the entirety of their options, so as to not skip out on something that may prove useful. The Illinois study, published in Clinical Psychological Science, asserts that it depends on the nature of the recommendations.

    According to the researchers, presenting a large amount of information would be appropriate if the goal would be for people to remember a large amount of potentially interchangeable behaviors, but if the goal is for people to remember a complete set of important recommendations, then the best strategy should be to present relatively few recommendations.

    “The best number of health behaviors to recommend seems to depend on the goal of an intervention,” Albarracin said. “If the goal is to communicate as many recommendations as possible, then go for a long list of behaviors. But if the goal is to implement behaviors, then the best strategy may be to convey a lower number of recommended behaviors.”

    The researchers, who also included Patrick McDonald at the University of Buffalo and Colleen Hughes at Indiana University-Bloomington (both are former members of Albarracin’s research group), came to their conclusion by analyzing the results of experiments in which participants were presented with a list of brief health recommendations (ranging in number from two to 20, with each recommendation being about 33 words long). They were then asked to recall as many recommendations as they could.

    Participants were also asked open-ended questions about their intentions to follow the recommendations. Even though more recommendations meant that participants recalled a lower proportion of the total, they recalled and intended to follow more recommendations.

    “When multiple health recommendations are necessary, knowing the influence of the number of recommendations on recall and intended compliance is critical,” the researchers wrote.

    This information can prove useful in many health fields. For example, psychotherapists who want to change the behavior of their patients in specific ways could assign homework, for example, that addresses one behavior. Other health professionals might give recommendations in small bursts (perhaps via text messaging) to help maximize the proportion of recalled recommendations while minimizing the costs to a patient.


  6. Less REM sleep tied to greater risk of dementia

    September 9, 2017 by Ashley

    From the American Academy of Neurology (AAN) press release:

    People who get less rapid eye movement (REM) sleep may have a greater risk of developing dementia, according to a new study published in the August 23, 2017, online issue of Neurology®, the medical journal of the American Academy of Neurology. REM sleep is the sleep stage when dreaming occurs.

    There are five stages of sleep. Stage one is light sleep. Stage two is when the body begins to prepare for deeper sleep, including stages three and four. Stage five is REM sleep. During this dream stage, the eyes move rapidly and there is increased brain activity as well as higher body temperature, quicker pulse and faster breathing. The first REM stage occurs about an hour to an hour-and-a-half into sleep and then recurs multiple times throughout the night as the cycles repeat.

    “Sleep disturbances are common in dementia but little is known about the various stages of sleep and whether they play a role in dementia risk,” said study author Matthew P. Pase, PhD, of Swinburne University of Technology in Australia. “We set out to discover which stages of sleep may be linked to dementia and while we did not find a link with deep sleep, we did with REM sleep.”

    For the study, researchers looked at 321 people with an average age of 67 from Massachusetts who participated in The Framingham Heart Study. During that study, sleep cycles were measured for each participant. Researchers collected the sleep data and then followed participants for an average of 12 years. During that time, 32 people were diagnosed with some form of dementia and of those, 24 were determined to have Alzheimer’s disease.

    The people who developed dementia spent an average of 17 percent of their sleep time in REM sleep, compared to 20 percent for those who did not develop dementia. After adjusting for age and sex, researchers found links between both a lower percentage of REM sleep and a longer time to get to the REM sleep stage and a greater risk of dementia. In fact, for every percent reduction in REM sleep there was a 9 percent increase in the risk of dementia. The results were similar after researchers adjusted for other factors that could affect dementia risk or sleep, such as heart disease factors, depression symptoms and medication use.

    Other stages of sleep were not associated with an increased dementia risk.

    “Our findings point to REM sleep as a predictor of dementia,” said Pase. “The next step will be to determine why lower REM sleep predicts a greater risk of dementia. By clarifying the role of sleep in the onset of dementia, the hope is to eventually identify possible ways to intervene so that dementia can be delayed or even prevented.”

    Limitations of the study include a small sample size. Studies on larger groups of people need to be done to confirm findings. There was also no data available on shift work among study participants, which can cause unusual sleep patterns and possibly lead to sleep disorders.


  7. Physical activity in midlife not linked to cognitive fitness in later years

    September 8, 2017 by Ashley

    From the Johns Hopkins University Bloomberg School of Public Health press release:

    A study led by Johns Hopkins Bloomberg School of Public Health researchers that tracked activity levels of 646 adults over 30 years found that, contrary to previous research, exercise in mid-life was not linked to cognitive fitness in later years.

    The finding suggests that physical activity may not help maintain cognitive function, or help avoid or delay the onset of the debilitating conditions like dementia and Alzheimer’s. Alzheimer’s affects as many as 30 million, mostly older people throughout the world. With no known treatment or cure, researchers are trying to identify measures that might help delay Alzheimer’s onset or limit its reach.

    The study, which appears online in the Journal of Alzheimer’s Disease, did find that activity levels among study participants in the later years were associated with high cognitive function two years later. This supports earlier research findings that exercise may help to maintain cognitive fitness in the short term.

    “This study reminds us that physical activity has all sorts of benefits for people, including promoting cardiovascular health, managing optimal weight levels and maintaining bone and muscle mass,” says Alden L. Gross, assistant professor in the Bloomberg School’s Department of Epidemiology. “Unfortunately it is too early for us to say the same about exercise and Alzheimer’s, especially as a possible long-term preventive measure.”

    There is no known treatment or cure for Alzheimer’s or dementia, syndromes that involves declining memory, confusion and eventually limited ability to perform daily tasks. To date, there are no preventive measures, such as physical exercise, brain games or a diet regimen, that have been proven to help delay or altogether prevent its onset. In the US, an estimated five million adults are currently living with Alzheimer’s, according to the Centers for Disease Control and Prevention (CDC), and the CDC predicts that this number will rise to 14 million by 2050.

    The researchers undertook the study because of a growing consensus that physical activity levels helps prevent Alzheimer’s, however much of the evidence for this thinking is based on cross-sectional studies that compare responses from one group of participants with another at a given point in time or within a very short duration, typically several years. Such studies can be valuable for confirming associations, or links, but not at establishing actual causation because of what is known as reverse causation: it is possible that people who eventually develop dementia may reduce their physical activity and exercise as dementia advances. That’s where longitudinal studies, which look at the same group of participants over a long time, are more helpful.

    The researchers used data from the Johns Hopkins Precursors study, which registered students studying at Johns Hopkins School of Medicine between 1948 and 1964 and tracked them with annual questionnaires about their overall health. The researchers note that the cohort’s homogeneity — students at a selective medical school — meant that any differences in physical activity and later cognitive function could not be explained by other differences among participants.

    The median age for study participants was 46 years in 1978 and 77 years in 2008. Every several years, the questionnaire asked about exercise, physical activity and physical limitations. The researchers used responses from 1978 through 2008 from 646 participants (598 men, 48 women) to calculate so-called metabolic equivalents, which quantify physical activity levels. Participants were also asked whether they regularly exercise to a sweat.

    The team administered cognitive tests in 2008, and, using participants’ medical records, scored for dementia through 2011. The researchers identified 28, or 4.5 percent of the cohort, to have Alzheimer’s.

    No physical activity measure in mid-life was associated with late-life cognitive fitness or onset of dementia. The study confirmed findings of other cross-sectional studies, that higher levels of physical activity and exercise measured close in time to the cognitive testing were associated with better cognitive functioning. The authors also looked at whether patterns of change in physical activity levels over the life span were associated with cognitive health and found no relationships.

    The idea that exercise might play a role in preventing or limiting Alzheimer’s makes sense, the researchers say, because physical activity, at least in mouse models, has shown less accumulation of B-amyloid plaques, which are thought to play a role in dementia, including Alzheimer’s. In addition, physical activity improves blood flow to the brain, which is linked to better cognitive performance. This may explain why studies find that exercise may contribute to cognitive fitness in the short term.

    “These findings have implications for intervention work moving forward,” says Gross. “We still need to focus on causes and mechanisms of Alzheimer’s and dementia, since we don’t yet know which preventive measures may or may not work. For now, when I speak in the community about Alzheimer’s, I find that people take some relief in understanding that there wasn’t anything that anyone might have done to avoid a loved one developing Alzheimer’s. Of course, the goal for researchers is to identify factors that may help older people maintain their cognitive function into their later years. More long-term studies like the Precursors study are needed.”


  8. New light on link between gut bacteria and anxiety-like behaviours

    by Ashley

    From the Biomed Central press release:

    Research published in the open access journal Microbiome sheds new light on how gut bacteria may influence anxiety-like behaviors. Investigating the link between gut bacteria and biological molecules called microRNAs (miRNAs) in the brain; researchers at the APC Microbiome Institute at University College Cork, which is funded by Science Foundation Ireland, found that a significant number of miRNAs were changed in the brains of microbe-free mice. These mice are reared in a germ-free bubble and typically display abnormal anxiety, deficits in sociability and cognition, and increased depressive-like behaviors.

    Dr Gerard Clarke, the corresponding author said: “Gut microbes seem to influence miRNAs in the amygdala and the prefrontal cortex. This is important because these miRNAs may affect physiological processes that are fundamental to the functioning of the central nervous system and in brain regions, such as the amygdala and prefrontal cortex, which are heavily implicated in anxiety and depression.”

    miRNAs are short sequences of nucleotides (the building blocks of DNA and RNA), which can act to control how genes are expressed. miRNA dysregulation or dysfunction is believed to be an underlying factor contributing to stress-related psychiatric disorders, neurodegenerative diseases and neurodevelopmental abnormalities. miRNA changes in the brain have been implicated in anxiety-like behaviors.

    Dr Clarke said: “It may be possible to modulate miRNAs in the brain for the treatment of psychiatric disorders but research in this area has faced several challenges, for example, finding safe and biologically stable compounds that are able to cross the blood-brain barrier and then act at the desired location in the brain. Our study suggests that some of the hurdles that stand in the way of exploiting the therapeutic potential of miRNAs could be cleared by instead targeting the gut microbiome.”

    The researchers found that levels of 103 miRNAs were different in the amygdala and 31 in the prefrontal cortex of mice reared without gut bacteria (GF mice) compared to conventional mice. Adding back the gut microbiome later in life normalized some of the changes to miRNAs in the brain.

    The findings suggest that a healthy microbiome is necessary for appropriate regulation of miRNAs in these brain regions. Previous research demonstrated that manipulation of the gut microbiome affects anxiety-like behaviors but this is the first time that the gut microbiome has been linked to miRNAs in both the amygdala and prefrontal cortex, according to the authors.

    The researchers used next-generation-sequencing (NGS) to find out which miRNAs were present in the amygdala and the prefrontal cortex of groups of 10-12 control mice with a normal gut microbiota, GF mice and ex-GF mice — which had been colonized with bacteria by housing them with the control mice — and adult rats whose normal microbiota had been depleted with antibiotics.

    They found that depleting the microbiota of adult rats with antibiotics impacted some miRNAs in the brain in a similar way to the GF mice. This suggests that even if a healthy microbiota is present in early life, subsequent changes in adulthood can impact miRNAs in the brain relevant to anxiety-like behaviors, according to the authors.

    The authors note that the exact mechanism by which the gut microbiota is able to influence the miRNAs in the brain remains unclear. Even though the study shows that effects of the microbiota on miRNAs are present in more than one species (mice and rats), further research into the possible connection between gut bacteria, miRNAs and anxiety-like behaviors is needed before the findings can be translated to a clinical setting.

    Dr Clarke said: “This is early stage research but the possibility of achieving the desired impact on miRNAs in specific brain regions by targeting the gut microbiota — for example by using psychobiotics — is an appealing prospect.”


  9. One in five women with postpartum mood disorders keep quiet

    by Ashley

    From the North Carolina State University press release:

    A recent study from North Carolina State University finds that 21 percent of recent mothers experiencing postpartum mood disorders (PPMDs), such as anxiety and depression, do not disclose their symptoms to healthcare providers.

    “Our study finds that many women who would benefit from treatment are not receiving it, because they don’t tell anyone that they’re dealing with any challenges,” says Betty-Shannon Prevatt, a practicing clinical psychologist and Ph.D. student at NC State who was lead author of a paper on the work.

    “We know that 10-20 percent of women experience significant mood disorders after childbirth, and those disorders can adversely affect the physical and emotional well-being of both mothers and children,” Prevatt says. “Our goal with this study was to see how many women are not disclosing these problems, since that’s a threshold issue for helping women access treatment.”

    To address this question, researchers conducted an anonymous survey of 211 women who had given birth within the previous three years. The survey asked women whether they’d experienced PPMD symptoms; whether they had disclosed PPMD symptoms to healthcare providers — from doulas and lactation consultants to nurses and doctors; and a range of questions related to their mental health and obstacles to seeking care.

    Survey responses showed that 51 percent of study participants met the criteria for a PPMD. However, just more than one in five of those who experienced PPMDs did not disclose their problems to healthcare providers.

    “To place this in context, there are national guidelines in place telling healthcare providers to ask women about PPMD symptoms after childbirth,” says Sarah Desmarais, an associate professor of psychology at NC State and co-author of the paper. “With so many women in our study not disclosing PPMDs to their providers, it strongly suggests that a significant percentage of these women did not disclose their symptoms even when asked.”

    The study found that women experiencing the highest levels of stress, and women with the strongest social support networks, were most likely to report their PPMD symptoms to healthcare providers.

    The study did not identify any specific barriers to disclosing PPMD symptoms. However, the study did find that women who were unemployed, had a history of mental health problems or were experiencing severe symptoms were more likely to report barriers to treatment — though the specific barriers to treatment varied significantly.

    “This work highlights the importance of support networks and the need to normalize the wide variety of reactions women have after childbirth,” Prevatt says. “We need to make it OK for women to talk about their mental health, so that they can have better access to care. Working with the people around new mothers may be key.”

    “We don’t just need to teach women how to develop a birth plan, we need to teach them how to develop a social support plan,” Desmarais says.

    The researchers are currently recruiting participants for a follow-up study aimed at addressing similar questions in Spanish-language communities.


  10. Study examines impact of nicotine reduction on vulnerable smokers

    September 7, 2017 by Ashley

    From the Larner College of Medicine at the University of Vermont press release:

    The FDA is right — when it comes to disease culprits, cigarette smoking tops the list. While recognized as the number-one cause of preventable disease and death, it’s an incredibly tough habit to break due to the addictiveness of nicotine. New research from the University of Vermont (UVM) and colleagues suggests that reducing nicotine content in cigarettes may decrease their addiction potential in especially vulnerable populations and suggests how regulatory policies could shift preferences to less-harmful tobacco products.

    The study appears in JAMA Psychiatry.

    The Vermont Center on Behavior and Health (VCBH) at UVM focuses on the relationship between behavior and health, particularly in disadvantaged populations, a group that is “overrepresented” among smokers, according to the study’s authors. In their latest study, the research team, led by Stephen Higgins, Ph.D., professor of psychiatry and VCBH director, examined the addiction potential of cigarettes with reduced nicotine content in three vulnerable populations of smokers — individuals with psychiatric disorders (i.e., affective disorders, opioid-use disorder), and socioeconomically disadvantaged women.

    Evidence in relatively healthy and socially stable smokers indicates that reducing the nicotine content of cigarettes reduces their addictiveness,” says Higgins. “Whether that same effect would be seen in populations highly vulnerable to tobacco addiction was unknown.”

    The multi-site, double-blind study is “the first large, controlled study to examine the dose-dependent effects of cigarettes with reduced nicotine content on the reinforcing effects, subjective effects, and smoking topography of vulnerable populations,” say the study’s authors.

    The study ran between March 2015 and April 2016 and included 169 daily smokers, including 120 women and 49 men. Participating centers included UVM, Brown University, Johns Hopkins University School of Medicine and the University of Kansas. A total of 56 of the participants were diagnosed with affective disorders, 60 with opioid dependence, and 53 were socioeconomically disadvantaged women. Each study participant completed fourteen 2- to 4-hour sessions, abstaining from smoking for 6 to 8 hours before each of the sessions, which were organized in 3 phases. Phase 1 included sessions 1 to 5 and included sampling of the research cigarettes in double-blind conditions, beginning with the smoking of the participant’s regular brand cigarette in session 1 and then smoking 1 research cigarette of identical appearance, but varying doses of nicotine in sessions 2 to 5. Participants were required to use a plastic cigarette holder when smoking research cigarettes, in order to measure smoking topography — number of puffs, length and speed of each puff.

    A Cigarette Purchase Task (CPR) was completed after each smoking session to measure the effects of cost on the participant’s rate of smoking. Additional questionnaires assessed research cigarette evaluation, nicotine withdrawal, smoking urges, and nicotine dependence.

    The Phase 2 sessions (6-11) provided participants with an opportunity to select which cigarette they preferred to smoke among 6 different dose combinations and used a computer program, which recorded which of two cigarettes participants preferred for that session and whether or not they wanted to continue to smoke that selection after two puffs or abstain. The final phase 3 (sessions 12-14) followed the same protocol, but measured only the highest and lowest doses of nicotine.

    While participants tended to prefer the higher nicotine dose content research cigarettes, the researchers found that the low-nicotine dose cigarettes could serve as economic substitutes for higher-dose commercial-level nicotine cigarettes when the cost of the latter was greater.

    Among the limitations of the study is its brief exposure to the research cigarettes. The authors report that field testing of extended exposure with these vulnerable populations to determine feasibility under “naturalistic smoking conditions” is underway.

    “This study provides a very encouraging indication that reducing the nicotine content of cigarettes would help vulnerable populations,” Higgins says. “We need more research, but this is highly encouraging news with tremendous potential to improve U.S. public health.”