1,720,959 research outputs found
The Influence of the Tricyclic Antidepressant Amitriptyline on Periodic Limb Movements during Sleep
No full textIntroduction: Many antidepressants are associated with periodic limb movements (PLM) during sleep. Although some tricyclic antidepressants, such as amitriptyline, promote sleep and are thus often prescribed as a treatment for sleep disturbances that can accompany depression, it remains unclear whether amitriptyline is associated with PLM. Methods: 32 healthy males (18-39 years) spent 2 consecutive nights in the sleep lab for polysomnographic recording. During the second night, they received either 75 mg amitriptyline or placebo in a randomized, double-blind, placebo-controlled manner. Results: In subjects receiving amitriptyline but not in subjects receiving placebo, the number of periodic leg movements per h was significantly increased from baseline to intervention night. However, objective polysomnographic sleep parameters (such. as the number of awakenings, wake after sleep onset, and sleep efficiency) and subjective sleep perception were not significantly associated with any PLM indices. Discussion: Our findings indicate that amitriptyline can induce or even increase the number of PLM during sleep in healthy subjects. When treating sleep disturbances with amitriptyline, PLM should be considered as a possible cause of insufficient improvement
Differential Effect of an Anticholinergic Antidepressant on Sleep-Dependent Memory Consolidation
No full textStudy Objectives: Rapid eye movement (REM) sleep is considered critical to the consolidation of procedural memory - the memory of skills and habits. Many antidepressants strongly suppress REM sleep, however, and procedural memory consolidation has been shown to be impaired in depressed patients on antidepressant therapy. As a result, it is important to determine whether antidepressive therapy can lead to amnestic impairment. We thus investigated the effects of the anticholinergic antidepressant amitriptyline on sleep-dependent memory consolidation. Design: Double-blind, placebo-controlled, randomized, parallel-group study. Setting: Sleep laboratory. Participants: Twenty-five healthy men (mean age: 26.8 +/- 5.6 y). Interventions: 75 mg amitriptyline versus placebo. Measurements/Results: To test memory consolidation, a visual discrimination task, a finger-tapping task, the Rey-Osterrieth Complex Figure Test, and the Rey Auditory-Verbal Learning Test were performed. Sleep was measured using polysomnography. Our findings show that amitriptyline profoundly suppressed REM sleep and impaired perceptual skill learning, but not motor skill or declarative learning. Conclusions: Our study is the first to demonstrate that an antidepressant can affect procedural memory consolidation in healthy subjects. Moreover, considering the results of a recent study, in which selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors were shown not to impair procedural memory consolidation, our findings suggest that procedural memory consolidation is not facilitated by the characteristics of REM sleep captured by visual sleep scoring, but rather by the high cholinergic tone associated with REM sleep. Our study contributes to the understanding of potentially undesirable behavioral effects of amitriptyline
Electronic media use and insomnia complaints in German adolescents: gender differences in use patterns and sleep problems
No full textElectronic media play an important role in the everyday lives of children and adolescents and have been shown to be associated with sleep problems. The objective of this study was to assess the associations between time spent using different electronic media and insomnia complaints (IC) in German adolescents with particular respect to gender differences in use patterns and associations with IC. Cross-sectional data of a weighted total of 7533 adolescents aged 11-17 stem from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS study) that was conducted from 2003 to 2006. The assessment of IC and time spent using different electronic media (television, computer/internet, video games, total screen time, mobile phones, and music) was included in a self-report questionnaire. Binary logistic regression analyses were performed to assess associations between time spent per day with each electronic media and IC. Age, SES, emotional problems (anxiety/depression) and presence of a medical condition were considered as covariates in the adjusted model. Boys and girls were considered separately. For boys: computer/internet use of >= 3 h/d (AOR = 2.56, p = 8 h/d (AOR = 2.45, p = 3 h/d was associated with IC (AOR = 4.24, p < 0.05) compared to non-listeners. Everyday use of electronic media devices is associated with IC in adolescents. Clinicians dealing with adolescents referred for sleep problems should be aware of gender-specific patterns of media use and sleep problems
Declarative memory consolidation during the first night in a sleep lab: The role of REM sleep and cortisol
No full textWhile the consolidation of declarative memory is supported by slow wave sleep (SWS) in healthy subjects, it has been shown to be associated with rapid eye movement (REM) sleep in patients with insomnia. Sleep during a subject's first night in an unfamiliar environment is often disturbed, and this so-called first-night effect (FNE) has often been used as a model of transient insomnia. Additionally, sleeping for the first time in an unfamiliar environment can lead to increased cortisol secretion, and declarative memory consolidation likely depends on low cortisol levels, especially during the early part of the night. Accounting for intersubject variability in the FNE, we examined the relationship between sleep stages, cortisol secretion and declarative memory performance in 27 healthy young men. Declarative memory performance improved significantly after sleep. Whereas memory performance during the learning session and retrieval testing was strongly associated with cortisol secretion, the overnight gain was not. Post hoc analyses indicated that the overnight gain appears to be modulated by the extent of the FNE: a significant overnight improvement in memory performance was found only in subjects with a weak FNE (n = 12). In these subjects, no association was found between any sleep stage and the improvement observed in their memory performance. In subjects with a strong FNE (n = 12), however, the overnight change in memory performance was associated with the proportion of REM sleep and the total number of REMs. Disturbed steep in an unfamiliar environment therefore appears to affect the memory consolidation process. (C) 2012 Elsevier Ltd. All rights reserved
Insomnia complaints and substance use in German adolescents: did we underestimate the role of coffee consumption? Results of the KiGGS study
No full textThe purpose of the study was to study the associations of tobacco, alcohol, marijuana, and coffee use and insomnia complaints (IC) in adolescents with special consideration of the influence of coffee consumption on these relationships. 7698 Subjects aged 11-17 years were investigated in a cross-sectional study within the German Health Interview and Examination Survey for Children and Adolescents. Self-report questionnaires were distributed to the participants. Hierarchical regression analyses were performed to assess possible effects of coffee consumption on the association of tobacco, alcohol, and marijuana use with IC. Common risk factors for insomnia were included in the adjusted analyses. Tobacco, alcohol, marijuana and coffee use displayed significant bivariate associations with IC. After adjusting the first three substances for coffee consumption, their associations with IC were reduced considerably. After additionally adjusting for other potential confounders (age, gender, socio-economic status, externalizing and internalizing psychiatric problems, media use, bodyweight, medical condition), frequent coffee consumption, high alcohol intake and frequent smoking contributed to the prediction of IC in male subjects while frequent coffee consumption and high alcohol intake predicted the occurrence of IC in females. Coffee consumption could be an important risk factor for IC in adolescents and it significantly affects the association of smoking, alcohol, and marijuana with IC. Future research that includes long-term studies about psychoactive substance use (PSU) and sleep should also consider coffee consumption. Parents, educators, clinicians, and researchers should be aware of the potentially hazardous influence of PSU, especially coffee, alcohol and tobacco, on sleep in young individuals
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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