Editor's Note: “Sleep that knits up the raveled sleave of care/The death of each day's life, sore labor's bath/Balm of hurt minds, great nature's second course/Chief nourisher in life's feast.” The quatrain from William Shakespeare in his play, Macbeth, reminds us each of how powerful is the theme the investigators from the Osher Center for Integrative Medicine chose for their mind–body exploration in this issue: sleep. The selection of articles includes an examination of the influence of a prison-based t'ai chi program on the disturbed sleep patterns in amphetamine addicts, a genetic exploration on mindfulness and sleep through a longterm study of twins, and then a third on the influence of yoga on the slumber of pregnant women. The signs are that with Shakespeare's positioning of sleep as the “chief nourisher,” mind and body practices may be said to nourish the nourisher. —John Weeks, Editor-in-Chief, JACM
T'ai chi for Amphetamine-Related Sleep Disorders in China: A Traditional Solution for a Modern Crisis
Peter M. Wayne, PhD.
Interim Director and Director of Research; Osher Center for Integrative Medicine; Harvard Medical School and Brigham and Women's Hospital
Amphetamine-type stimulants (ATS) are the second most prevalent drugs used globally and are a major public health concern. China is now recognized as a major region of methamphetamine (MA) production and trafficking, and the prevalence of MA addiction among Chinese nationals is growing exponentially. MA use is associated with serious health consequences, including high risk of mortality, poor physical status, cognitive impairment, and sleep disorders. Prior small studies have suggested that t'ai chi and other mind–body therapies that aim to enhance physical and emotional self-regulation show promise in reducing rates of recidivism after heroin and cocaine addiction programs, and more generally improve sleep and mood disturbances. However, research evaluating the potential of t'ai chi to treat amphetamine-related sleep disorders is very limited.
This randomized trial led by researchers at Shanghai University of Sport assessed the effects of a 6-month course of t'ai chi training versus routine rehabilitation on Chinese female ATS dependents' sleep behavior, mental and physical health, and rates of recidivism.1 A total of 80 women (average age: 35.7 years) were recruited from within a government-run mandatory detoxification and rehabilitation center. Eligibility criteria included the following: formal classification as both a “level-3 illicit drug-dependent user” and an ATS-dependent; no Axis 1 psychiatric disorders; no illnesses that affect the central nervous system; and no current treatment with pharmacologic or psychotropic medications. The t'ai chi program consisted of group classes (5 times/week for first 3 months; 3 times/week for second 3 months). The control intervention included a combination of instructor-led exercise and self-education (e.g., health-related reading and television). All participants also were required to adhere to additional detention center protocols, including participation in a detoxification program and manual labor. The study team hypothesized that compared with the standard rehabilitation program, the addition of t'ai chi would improve sleep quality, overall health, and rates of postprogram recidivism.
In the t'ai chi and control group, 35 and 14 participants, respectively, completed the study. Baseline demographics of study completers and noncompleters were not statistically different. However, overall randomization resulted in chance baseline differences in a number of key factors, including poorer sleep-related metrics in the t'ai chi group. Repeated ANOVAs limited to completers indicated that compared with controls, t'ai chi improved overall Pittsburg Sleep Quality Index scores, sleep duration, and habitual sleep efficiency. In addition, t'ai chi led to significant reductions in use of sleep medications (from 71.5% to 2.7%). Average resting heart rate also significantly decreased in the t'ai chi group. Finally, relapse rates, based on auditing of government drug abuser data bases >2 years postprogram graduation suggested statistically lower relapse rates in the t'ai chi versus control group (9.5% vs. 26.3%).
High dropout rates, significant baseline differences, small sample size, and other methodological weaknesses significantly limit the conclusions that can be drawn from this study. Nevertheless, the provocative findings suggest that old-school traditional therapies such as t'ai chi may provide a solution to a significant public health crisis caused by modern society. Given the general importance of sleep in physical and mental health, both in substance- and nonsubstance-dependent populations, these data support a promising nonpharmacologic option for managing this critical function. And given that the number of MA-related deaths in the United States are approaching those associated with opioid misuse, findings from the study support the broader potential of mind–body assisting populations trapped in this horrible epidemic. Future studies carried out with more rigorous methods and across different cultures are needed to better inform the role t'ai chi and related mind–body practices can play in global substance abuse epidemics.
Citation: 1. Dong Z, Guobine D, Ding X, et al. Long-term effects of Tai Chi intervention on sleep and mental health of female individuals with dependence on amphetamine-type stimulants. Front Psychol 2018;9:1476.
Getting a Good Night Sleep in Pregnancy—What Might Yoga Offer?
Darshan H. Mehta, MD, MPH.
Medical Director, Benson-Henry Institute for Mind Body Medicine; Massachusetts General Hospital; Associate Director of Education; Osher Center for Integrative Medicine; Harvard Medical School and Brigham and Women's Hospital
For many women, pregnancy often results in altered sleep. It is among the most noticed changes and is a topic that women regularly seek information on; epidemiologic studies have suggested that nearly half of pregnant women report having sleep disturbances. During pregnancy and the postpartum period, women are at particular risk for sleep restriction. In addition, pregnancy is a time when women are at a heightened risk of depression. Since there is limited data on what constitutes healthy sleep in pregnancy, health care providers are unable to advise women on what changes are within the range of normal. Moreover, there are very limited pharmacologic options—due to the lack of studies done in pregnant women, and the theoretical and/or observed risks to the fetus. Lastly, the majority of sleep studies have been done in men.
Nonpharmacologic strategies (e.g., cognitive behavioral therapy), although underutilized, have been shown to very effective in the management of sleep disturbances and sleep disorders. As one such strategy, yoga has been suggested to have therapeutic value in the management of sleep disturbances and sleep disorders. In fact, there are approaches in yogic traditions (i.e., yoga nidra) that are specifically targeted for sleep.
In this case–control prospective cohort study by Hayase and Shimada,1 38 women (mean age 34) from a hospital-based outpatient clinic participated in a weekly 1-h yoga class during the course of their pregnancy (16 weeks' gestation and continued until delivery), led by instructors who completed a maternity yoga training course. The curriculum included asanas (postures), pranayama (breathwork), and meditation. The study article described their yoga protocol. Attendees were also instructed 15 min daily home practice. The control group were women (n = 53) who visited the same outpatient clinic during the same gestational age range and who were matched for age (mean age 33) and gravidity.
During three gestational periods (20–23, 28–31, and 36–40 weeks), self-reported outcomes, (Perceived Stress Scale and a sleep log), and salivary cortisol (assess changes in α-amylase before and after a yoga session) were collected. In the control group, these outcomes were collected before the clinic session during that trimester. In addition, heart rate variability was assessed for a 24-h period using a wearable tracker; this outcome characterized sympathetic and parasympathetic tone.
Women in the yoga group participated in a median of eight sessions, from their start in the program until delivery. Of note, there were no significant differences in perceived stress between the groups in any trimester. With regard to salivary amylase, there were no differences at baseline between the groups; however, for each trimester, salivary amylase levels significantly decreased after practicing yoga for that single session. Analysis of heart rate variability suggested yoga training increased parasympathetic tone significantly at night and late night at 28–31 weeks' gestation. During 36–40 weeks' gestation, there was greater sympathetic tone in the morning, afternoon, and late night, as compared with control group. Finally, night sleep time was significantly longer in the yoga group at 28–31 weeks' and at 36–40 weeks' gestation. There was also a significant positive correlation between the number of yoga sessions attended and night sleep time.
This is a small nonrandomized pilot study. Moreover, individuals who participated in the yoga program did have significantly more prior experiences with yoga. Nevertheless, this study is important to pay attention to for several reasons. First, it focuses on pregnant women. Second, it focuses on sleep. Third, it uses both self-report and measured data to describe findings. Fourth, it studies a nonpharmacologic strategy.
Longer night sleep time and the increase in parasympathetic tone suggest sleep was consolidated. In addition, it was interesting to see the additive effect suggested by the number of sessions attended. Of note, although the study was approved by an ethics committee, it is not clearly stated as to whether there were no reports of adverse events. Although by no means is this study definite, it offers a path forward for future research in a population and a condition that has not been well studied. And perhaps, it begins to offer options to health care providers and patients that are safe, replicable, and longitudinal. Finally, as an academic community, data systems might be set in ways we can begin to think about the long-term consequences to the offspring based upon pre- and perinatal actions.
Citation: 1. Hayase M, Shimada M. Effects of maternity yoga on the autonomic nervous system during pregnancy. J Obstet Gynaecol Res 2018;44:1887–1895.
Mindfulness and Sleep: Understanding Both Nature and Nurture
Gloria Y. Yeh, MD, MPH.
Director, Research Fellowship in Integrative Medicine; Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center; Interim Associate Director of Research; Osher Center for Integrative Medicine; Harvard Medical School and Brigham and Women's Hospital
The nature versus nurture discussion has long been an important provocative topic within medicine. For the most part, the discussion has rarely been one sided. We recognize that both genetics and environment play important roles in shaping who we are, including our physical, cognitive, and emotional health. As we enter the new and exciting era of precision medicine, it is in fact this underlying premise that allows us to consider the genetic basis of traits alongside the environmental context to allow a more sophisticated targeted treatment approach for individuals.
For the past decade, advances in genomics have allowed us to better understand one of the most fundamental, yet complex human traits—sleep. There is a growing literature on the genetic basis of sleep regulation, physiology, and circadian rhythms, as well as sleep disorders. These acknowledge the contributions of gene and environment and interactions between the two. Mindfulness, a core construct within mind–body medicine, is garnering increased attention as a promising strategy to improve sleep health in various populations. In contrast to the genetic basis of sleep, very little is known about the genetic basis of mindfulness. Since mindfulness can be conceptualized as a state, a trait, or a skill that can be learned, its origins and etiologies—including genetic or environmental influences—are thus far unclear.
In an interesting twin/sibling analysis, Schneider et al.1 begins to explore the origins of mindfulness by examining the genetic correlations and associations between mindfulness and symptoms of insomnia, depression, and anxiety in twin and sibling pairs. This study utilized data from one wave of the Genesis 12–19 study where the Five Facet Mindfulness Questionnaire was administered (N = 862 individuals; age range 22–32 years, 66% were women). Genesis 12–19 is an ongoing longitudinal study in the United Kingdom of twin and nontwin sibling pairs that has followed subjects from adolescence into early adulthood. It was initially designed to examine the gene-environment in depression. By comparing monozygotic twins (genetically identical) with dizygotic twins (about 50% identical), and assuming that twin pairs share similar environments, investigators could make inferences about genetic and environmental influences on phenotype mindfulness traits. Associations between these correlations and symptoms of insomnia and related mood disturbances were then examined utilizing correlated factors solution, as well as independent pathway and common pathway multivariate models.
Investigators found that less trait mindfulness was associated with greater symptoms of insomnia, depression, and anxiety (r = 0.22–0.48). Of the mindfulness facet subscales, a lower score on “nonjudging of inner experience” was most highly correlated with symptoms of insomnia (r = 0.34, p < 0.01), depression (r = 0.54, p < 0.01), and anxiety (r = 0.55, p < 0.01). This nonjudging facet of mindfulness is described as the tendency toward objective consideration of thoughts and feelings without assigning value to them. This study suggests it may be protective toward better sleep. Mindfulness was more strongly correlated with insomnia symptoms in monozygotic than dizygotic twins, indicating possible genetic influence. Results also suggested that familial influences (combination of genetics and environment shared by siblings) play a role, particularly for “acting with awareness” (an individual's ability to stay present and aware in the moment), and “describing” (the ability to recognize and label thoughts and feelings). The genetic correlations between other nonfamilial environmental influences (not shared between siblings) with mindfulness and symptoms of insomnia, depression, and anxiety were also prominent (r = 0.21–0.55).
Not surprisingly, this study confirms a mixed picture, with both genetic and environmental influences at play with both mindfulness and sleep. Practically, this supports the value of optimizing environmental and experiential exposures, perhaps with particular attention to the facets of mindfulness that cultivate objective nonjudgment of the inner experience that may address a psychologic pathway of sleep disturbance. The burgeoning field of epigenetics is now widening the nature versus nurture discussion even more, as genetic influences are not all predetermined and set in stone, and we discover the possibility for nature and nurture to further interact. Among the promises of precision medicine, the hope is to better predict susceptibility to disease, preempt progression, customize treatment strategies, and shift from reaction to prevention. If we can understand and identify those most at risk (e.g., with lower trait mindfulness and predisposed to sleep issues), might we make a greater contribution by proactively targeting these populations with nonpharmacologic mind–body interventions?
Citation: 1. Schneider MN, Zavos HMS, McAdams TA, et al. Mindfulness and associations with symptoms of insomnia, anxiety and depression in early adulthood: A twin and sibling study. Behav Res Ther 2018;118:18–29.