Methamphetamine attenuates disruptions in performance and mood during simulated night-shift work.
ABSTRACT Increased sleepiness while working and sleep disruptions are common complaints among shift workers. Consequently, shift workers may be more susceptible to diminished performance and work-related accidents.
To examine the effects of the central nervous system stimulant methamphetamine on psychomotor task performance, subjective effects, and food intake during shift work under laboratory conditions.
Seven participants completed this 23-day, within-participant design, residential laboratory study. They received a single oral methamphetamine dose (0, 5, 10 mg) 1 h after waking for three consecutive days under two shift conditions: (1) during the day shift, participants performed computerized psychomotor tasks from 0830 hours to 1730 hours and went to bed at 2400 hours and (2) during the night shift, participants performed tasks from 0030 hours to 0930 hours and went to bed at 1600 hours. Shifts alternated three times during the study; shift conditions were separated by an "off" day during which participants were not on a schedule and data were not collected.
When participants received placebo, psychomotor task performance and subjective effects were disrupted during the night shift, relative to the day shift. Changing shift conditions did not alter food intake significantly. Methamphetamine reversed performance and subjective-effects disruptions, and decreased food intake during the night shift.
These data indicate that shift changes produce performance impairments and mood alterations, and that a single low to moderate dose of methamphetamine attenuates many shift change-related disruptions in performance and mood.
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ABSTRACT: Although not all individuals who work outside of standard daytime hours develop physical and psychiatric issues, there is a substantial portion of shift workers who develop shift work disorder. Shift work disorder is due to a misalignment between an individual's endogenous circadian rhythms and environmental stimuli, and can have potentially serious consequences to an individual's health and quality of life. This article reviews the neurobiological and genetic underpinnings of shift work disorder, and describes how desynchronization of the molecular clock may lead to both physical and psychiatric illnesses. Diagnostic tools and treatment guidelines to address the circadian misalignment, excessive sleepiness, and insomnia experienced by patients with shift work disorder are also discussed.CNS spectrums 12/2013; 18(s1):42-54. · 1.30 Impact Factor
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ABSTRACT: Introduction: Sleep disorders are a major problem for nurses, while lack of adequate sleep and tiredness due to sleep deprivation may have an impact on the nurses’ professional performance and quality of life, putting their mental stability at stake. Aim: The aim of the present study is to investigate risk factors and causes that lead to sleep disorders in nurses working on rotating shifts, and the impact they may have on the nurses’ quality of life, professional performance and general health, as well as to discuss means of interventions in order for those disorders to be dealt with. Method: All relevant literature of the last twenty years was reviewed by using authoritative databases and indexes, such as PubMed and Cinahl. The following key-words were used: “sleep disorders”, “nurses”, “occupational characteristics”, “sleep medication”, alone or in combination. Among all the studies available, only those that were strictly relevant to the subject under investigation were included in the review. Circadian rhythm disorders, lack of sleep, and excessive somnolence can inhibit one’s learning process, ability to stay focused, memory and working performance. According to DSM-IV, the diagnosis of shift work disorder (SWD) can be established when someone experiences excessive somnolence and/or sleeplessness for a month or even more, and that person works on shifts. Nurses usually work on rotating shifts, something that may lead to workplace and traffic accidents or several diseases, while it has been shown to affect a person’s ability to sleep, eat properly, exercise and create interpersonal relationships. Therapeutic interventions aim at establishing the person’s ability to be on full awareness and also get adequate sleep with no problems. Conclusions: Sleep disorders due to working on shifts have become a public health issue, since they can lead to behavioural disorders, accidents, and also increase morbidity. The main method of preventing the effects of sleep disorders in nurses is to provide timely information, counseling, screening and appropriate treatment. Keywords: nurses, occupational characteristics, sleep disorders, sleep medicationInterscientific Health Care. 01/2013; 5(2):40-48.
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ABSTRACT: Armodafinil is a medication used to treat excessive sleepiness in individuals with shift work disorder (SWD). In the present study, we investigate whether armodafinil can normalize nocturnal sleepiness in a group of typical SWD patients. Participants were 12 night workers (aged 33.8 ± 8.57 years, 7 female subjects) with excessive sleepiness (≥10 on the Epworth Sleepiness Scale; mean, 14.8 ± 3.16), meeting the International Classification of Sleep Disorders, Second Edition criteria for SWD, with no other sleep or medical disorders verified by polysomnogram. The multiple sleep latency test (MSLT) was not used as an entry criteria. Armodafinil was administered at 10:30 PM in a randomized, double-blind, placebo-controlled, crossover design with experimental nights separated by 1 week. Primary end point was the MSLT, with naps at 1:30, 3:30, 5:30, and 7:30 AM. Other study measures included a sleepiness-alertness visual analog scale administered before each nap, and 2 computer-based performance tests evaluating attention and memory. Subjects with SWD had a mean MSLT of 5.3 ± 3.25 minutes, indicating a mean level of pathological sleepiness. Armodafinil significantly improved MSLT score to 11.1 ± 4.79 minutes (P = 0.006). Subjective levels of alertness on the visual analog scale also improved (P = 0.008). For performance, reaction time to central (P = 0.006) and peripheral (P = 0.003) stimuli and free recall memory (P = 0.05) were also improved. Armodafinil 150 mg administered at the beginning of a night shift normalizes nocturnal sleepiness in individuals with SWD unselected for objective sleepiness. Subjective measures of sleepiness and cognitive performance are also improved. This suggests that armodafinil can improve levels of nocturnal alertness to within normal daytime levels in the majority of patients with SWD.Journal of clinical psychopharmacology 04/2014; · 5.09 Impact Factor