Masahiro Suzuki’s research while affiliated with National Institute of Mental Health (NIMH), National Institutes of Health and other places

This study aimed to investigate the prevalence of daytime sleepiness (DS) and its impact on quality of life (QOL) in outpatients with schizophrenia in the maintenance phase, as well as to identify the factors associated with DS. A total of 191 outpatients with schizophrenia completed a self-administered questionnaire including questions on lifestyle, sleep habits, DS, QOL, and sleep disorders. Insomnia, DS, and QOL were evaluated by the Athens Insomnia Scale (AIS), the Epworth Sleepiness Scale (ESS), and the MOS 8-Item Short-Form Health Survey (SF-8), respectively. The prevalence of DS was assessed with two cut-off points, ESS ≥ 11 (ESS11-DS) and ESS ≥ 8 (ESS8-DS). Psychiatric symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Logistic regression analyses were used to identify factors associated with DS. The prevalence of ESS11-DS and ESS8-DS was 7.3% and 21.5%, respectively. Seven of eight QOL domains were reduced in the ESS11-DS group, and four of eight QOL domains were reduced in the ESS8-DS group. In both groups, the Mental Component Summary Score of the SF-8 was decreased. On logistic regression analyses, severity of insomnia was associated with both ESS11-DS and ESS8-DS. Moreover, negative symptoms were associated with ESS11-DS. Psychotropic medications were not associated with either ESS11-DS or ESS8-DS. The present findings suggest that focusing on improving insomnia, rather than reducing medication dosage, may be more important in ameliorating DS and, consequently, QOL in patients with schizophrenia in the maintenance phase.

A randomised, placebo-controlled, parallel-group study was conducted to examine the effect of periocular skin warming before bedtime on sleep and anxiety in female workers with mild sleep difficulty. A total of 64 participants were included in the study, which consisted of a 1-week baseline period and a 4-week intervention period. They were randomly assigned to either the Warm group (N = 32) or the Sham group (N = 32) and were instructed to wear eye masks (warming or sham) before their habitual bedtime during the intervention period. The study found that the Athens Insomnia Scale score after the intervention was significantly lower in the Warm group compared to the Sham group. Additionally, participants in the warm condition showed a decrease in subjective sleep onset latency, better restorative sleep, and improved subjective anxiety before bedtime. A significant reduction in wake after sleep onset was observed in the Warm group at 4 weeks, and this decrease was significantly associated with the degree of improvement in subjective anxiety before bedtime. Furthermore, regular periocular skin warming before bedtime decreased sleep reactivity and improved well-being. In conclusion, the study suggests that periocular skin warming may be an effective approach for female workers with sleep problems, as it can easily be incorporated into daily life.

Aim Mental health issues in adolescence contribute to various disease burdens later in life and are associated with violence, crime, and suicide. Activities such as sleep, diet, exercise, and time spent using electronic devices are related to declining mental health. However, few studies have examined the association between commuting times to school and mental health. This study tested the hypothesis that high school students' long commuting times are associated with poor mental health. Method A cross‐sectional study was conducted between October and December 2022 among 2067 students at two private high schools. Survey items included participant information (sex, grade, school), commuting time, mental health status (Patient Health Questionnaire 9 [PHQ‐9]: depressive symptoms, and Generalized Anxiety Disorder 7 [GAD‐7]: anxiety symptoms), lifestyle factors, and sleep‐related factors. Results Data from 1899 high school students were analyzed. The prevalence of depressive and anxiety symptoms was 17.3% and 19.0%, respectively. A commuting time of ≥1 h was significantly associated with depressive symptoms (adjusted odds ratio: 1.60 [95% confidence interval]: 1.14–2.24) and anxiety symptoms (adjusted odds ratio: 1.51 [95% confidence interval]: 1.09–2.10). Sex, grade, use of ≥8 h/day of electronic devices, and chronotype were significantly associated with depressive symptoms, while sex, grade, use of ≥8 h/day of electronic devices, and insomnia were significantly associated with anxiety symptoms. Conclusion It is suggested that long commuting times are associated with poor mental health in high school students. Parents and schools should consider commuting time when advising students on school selection to maintain their mental health.

Background Palilalia is a type of speech characterized by compulsive repetition of words, phrases, or syllables. Several reports have noted that palilalia can occur in response to external verbal stimuli. Here, we report, for the first time, a patient with palilalia induced by gait, which we call “movement-related palilalia.” Case presentation Eleven months after the onset of cerebral infarction sparing the right precentral gyrus and its adjacent subcortical regions, a 63-year-old, left-handed Japanese man was referred for psychiatric consultation because of a complaint of irritability caused by the stress of compulsive repetition of a single meaningless word, “wai.” The repetition of a word, palilalia, in this case, was characterized by its predominant occurrence during walking and by its melodic tones. The palilalia during walking disappeared almost completely after 5 months of treatment with carbamazepine 600 mg. Conclusion Palilalia induced by gait can occur in patients with a history of cerebral infarction. This palilalia during walking may be due to the reorganization of networks in areas nearby or surrounding cerebral infarcts.

Background It is unclear how primary care physicians manage insomnia after the introduction of novel hypnotics such as orexin receptor antagonists and melatonin receptor agonists. This Web-based questionnaire survey aimed to examine treatment strategies for insomnia in Japanese primary care practice. Methods One-hundred-and-seventeen primary care physicians were surveyed on the familiarity of each management option for insomnia on a binary response scale (0 = “unfamiliar”; 1 = “familiar”) and how they managed insomnia using a nine-point Likert scale (1 = “I never prescribe/perform it”; 9 = “I often prescribe/perform it”). Physicians who were unfamiliar with a management option were deemed to have never prescribed or performed it. Results Regarding medication, most physicians were familiar with novel hypnotics. Suvorexant was the most used hypnotic, followed by lemborexant and ramelteon. These novel hypnotics averaged 4.8–5.4 points and 4.0–4.7 points for sleep onset and sleep maintenance insomnia, respectively. By contrast, most benzodiazepines were seldom used below two points. Regarding psychotherapy, only approximately 40% of the physicians were familiar with cognitive behavioral therapy for insomnia (CBT-I) and they rarely implemented it, at an average of 1.5–1.6 points. More physicians were familiar with single-component psychotherapies (i.e., relaxation, sleep restriction therapy, and stimulus control) compared to CBT-I, and 48–74% of them implemented it slightly more often, with scores ranging from 2.6 to 3.4 points. Conclusion This study suggests that Japanese primary care physicians seldom use CBT-I to treat insomnia. In addition, they use novel sleep medications more frequently than benzodiazepines in terms of pharmacotherapy. The use and availability of CBT-I in Japanese primary care might be facilitated by: educating primary care physicians, implementing brief or digital CBT-I, and/or developing collaborations between primary care physicians and CBT-I specialists.

Introduction Subjective sleep duration often differs from objective measurements. Our prior research indicates that overestimating sleep duration may be a risk factor for all-cause mortality in older men. Conversely, those with insomnia, which is an another mortality risk factor, typically underestimate their sleep duration. This study investigates how both underestimation and overestimation of sleep duration impact all-cause mortality in community-dwelling older men (aged ≥ 65) comparing with and without insomnia symptoms. Methods We conducted a secondary analysis using data from the Osteoporotic Fractures in Men Sleep Study, involving 2,200 participants who underwent in-home polysomnography and completed surveys assessing their subjective sleep duration, without using sleep-affecting medication (such as antidepressants, hypnotics or benzodiazepines). Insomnia was defined by a Pittsburgh Sleep Quality Index (PSQI) score over 5 (N = 816). We examined the relationship between subjective-objective sleep duration discrepancy index (SODI) and mortality using Cox regression. SODI, the ratio of subjective to objective sleep duration, was analyzed categorically, comparing its lowest and highest quartiles to the interquartile range within each group. The study was approved by the Ethics Committee of the National Center of Neurology and Psychiatry. Results During follow-up periods (mean: 10.6 years for insomniacs, 11.2 years for non-insomniacs), 504 (61.8%) insomniacs and 774 (55.9%) non-insomniacs died. In the insomnia group, both the lowest (adjusted Hazard Ratio [HR], 1.31; 95% Confidence Interval [CI], 1.02–1.68) and the highest (adjusted HR, 1.31; 95% CI, 1.03–1.66) SODI quartiles were associated with increased mortality compared to the interquartile range. Conversely, in the non-insomnia group, only the highest SODI quartile showed a significant increase in mortality (adjusted HR, 1.30; 95% CI, 1.07–1.59), with the lowest quartile showing no significant mortality association (adjusted HR, 0.94; 95% CI, 0.78–1.14). Conclusion Results demonstrate the significant role of subjective-objective sleep duration discrepancy in long-term health outcomes in both the insomnia and the non-insomnia group. Further physiological studies may elucidate the mechanisms of subjective-objective sleep duration discrepancy on mortality. Support (if any) This study received a grant-in-aid for scientific research from the Ministry of Health, Labor and Welfare, Government of Japan (grant numbers #19FA1009 and #21FA1002).

Background Insomnia is known to be a major risk factor for incident hypertension. Nonrestorative sleep (NRS), which refers to insufficiently rested sleep, has reported to associate with various diseases. This study aimed to investigate the longitudinal association between insomnia-related symptoms including NRS and incident hypertension 1–2 years later by age group (young, 18–39 years and middle-age, 40–64 years) using existing cohort data involving Hispanics/Latinos. Methods This study included 1100 subjects who had participated in both the Hispanic Community Health Study/Study of Latinos and its follow-up study, the Sueño Ancillary Study, and met additional eligibility criteria. Incident hypertension was assessed by self-reported history and/or the use of antihypertensives. The Women’s Health Initiative Insomnia Rating Scale (WHIIRS) was used to evaluate insomnia-related symptoms (difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, difficulty returning to sleep, and NRS). Logistic regression analyses were conducted to assess the degree to which insomnia-related symptoms at baseline predicted incident hypertension. Results Among the participants (64% middle-aged, 36% young adults), 140 (12.7%) developed hypertension during the follow-up period. Among the sleep-related symptoms, only NRS predicted incident hypertension after adjusting for sociodemographic factors and physical condition (odds ratio: 1.88, 95% confidence interval: 1.10–3.21, p = 0.022) in middle-aged adults. None of the insomnia-related symptoms were associated with incident hypertension in the young adults. No association was found between WHIIRS-defined insomnia (total score ≥ 9) and incident hypertension in middle-aged adults or young adults. Conclusion The present findings suggest the importance of focusing on NRS to help prevent the development of hypertension in middle-aged adults.

Objectives: Nonrestorative sleep (NRS) and excessive daytime sleepiness (EDS) are important indicators of daytime dysfunction. Electronic media use before bedtime greatly affects adolescent sleep quality. However, few studies have examined factors associated with these symptoms. Therefore, we aimed to investigate the impact of chronotype, electronic device use before bedtime, and insomnia symptoms on NRS and EDS in Japanese adolescents. Methods: A web-based cross-sectional survey of 2067 adolescents was conducted in 2022 to mainly assess sleep-related issues (sleep duration, chronotype, insomnia symptoms, NRS, and EDS), time spent using electronic devices, physical activity, and mental health. Results: We analyzed data of 1880 adolescents (age, 16.4 ± 0.8 years; males, 56.7%). NRS and EDS prevalence rates were 54.9% and 39.4%, respectively. In multivariate analysis, evening chronotype [odds ratio (OR): 2.14, 95% confidence interval (CI): 1.58-2.89], difficulty initiating sleep (OR: 1.94, 95% CI: 1.43-2.64), <5 h sleep (OR: 1.77, 95% CI: 1.24-2.54), 5-6 h sleep (OR: 1.52, 95% CI: 1.20-1.93), and using electronic devices just before bedtime (OR: 1.48, 95% CI: 1.08-2.04) were associated with NRS. Evening chronotype (OR: 1.40, 95% CI: 1.07-1.82), early morning awakening (OR: 1.60, 95% CI: 1.02-2.50), using electronic devices just before bedtime (OR: 2.08, 95% CI: 1.48-2.93), and using electronic devices 30 min before bedtime (OR: 1.57, 95% CI: 1.07-2.29) were associated with EDS. Conclusion: Chronotype may be an important factor influencing NRS and EDS. Discontinuing electronic device use at least 30 min before bedtime could benefit affected adolescents.