Motohiro Nakajima

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Repeated exposures to psychological stress can lead to or worsen diseases of slow accumulation such as heart diseases and cancer. The main challenge in addressing the growing epidemic of stress is a lack of robust methods to measure a person's exposure to stress in the natural environment. Periodic self-reports collect only subjective aspects, often miss(More)
The current study examined whether prequit trait negative mood and smoking motives have different predictive patterns of smoking relapse in men and women. Thirty-three female (mean age±SEM: 34.9±2.5) and 38 male (mean age±SEM: 37.1±2.3) smokers interested in smoking cessation completed forms on smoking history, negative mood (i.e., depression, anxiety, and(More)
Recent advances in mobile health have produced several new models for inferring stress from wearable sensors. But, the lack of a gold standard is a major hurdle in making clinical use of continuous stress measurements derived from wearable sensors. In this paper, we present a stress model (called <i>cStress</i>) that has been carefully developed with(More)
INTRODUCTION Khat (Catha edulis) is widely used in East Africa and the Middle East, often in combination with tobacco smoking. Sleep disturbance has been linked with habitual khat use; however, no systematic attempt has been made to test the hypothesis that use of khat and khat and tobacco in combination are related to sleep disturbance. Sleep disturbances(More)
INTRODUCTION Dysregulation in the hypothalamic-pituitary-adrenal axis has been shown to be associated with smoking relapse. No study has directly examined the role of sex differences in this relationship. METHODS Nicotine dependent men (n = 52) and women (n = 46) interested in cessation completed 2 laboratory stress sessions during ad libitum smoking and(More)
Chronic smoking has been linked with alterations in endogenous pain regulation. These alterations may be pronounced when individuals quit smoking because nicotine withdrawal produces a variety of psychological and physiological symptoms. Smokers interested in quitting (n = 98) and nonsmokers (n = 37) completed a laboratory session including cold pressor(More)
Alterations in the stress response and endogenous pain regulation mechanisms may contribute directly and indirectly to maintenance of nicotine dependence and relapse. We examined the extent to which nicotine dependence alters endogenous pain regulatory systems, including the hypothalamic-pituitary-adrenocortical axis, cardiovascular activity, and(More)
Recent research suggests a role for the appetite hormone leptin in cigarette smoking. This study examined patterns of change in leptin in response to stress and associations with craving during the initial phase of a quit attempt. Thirty-six smokers (average age±SEM, 33.4±2.4) interested in smoking cessation set a quit day and were required to be abstinent(More)
Appetite hormones are directly involved in regulating satiety, energy expenditure, and food intake, and accumulating evidence suggests their involvement in regulating reward and craving for drugs. This study investigated the ability of peptide YY (PYY) and ghrelin during the initial 24-48 h of a smoking cessation attempt to predict smoking relapse at 4(More)
This study examined patterns of change in postcessation withdrawal symptoms and basal adrenocortical activity of smokers who were abstinent over a 4-week period (n = 18) and those who relapsed within the first week (n = 35). Participants interested in smoking cessation attended a prequit assessment in which they completed multiple forms associated with(More)