Association Between Perceived Stress and Burnout Among Neonatal Intensive Care Nurses.

Methamphetamine use has become a growing public health concern both within the United States and across the world, with its associated morbidity and mortality escalating in recent years (; ; ). In fact, methamphetamine has surpassed all drugs of abuse in overdose deaths except for synthetic opioids (). Methamphetamine induces euphoria, heighted alertness, and decreased appetite (). Its use is also associated with several negative health effects, including tachycardia, cardiotoxicity, hyperthermia, seizures, perceptual disturbances, and agitation (). Of note, methamphetamine also induces alterations in sleep-wake cycles and circadian rhythms (). Both clinical (; ) and pre-clinical () studies have shown that methamphetamine causes a decrease in total sleep time and an increase in nighttime awakenings, in addition to disruptions in sleep architecture (decreases in REM and N3 sleep time) (). Recent studies have proposed the use of the opioid receptor antagonist naltrexone for the treatment of methamphetamine use disorder. Oral naltrexone administration reduced methamphetamine use as evidenced by negative urine drug screens in a 12-week double-blind placebo controlled trial (). These finding corroborate previous studies showing that naltrexone reduced cue-induced craving and the subjective effects of methamphetamine (). Naltrexone has also shown promise as a therapeutic for methamphetamine use disorder as a combination therapy with bupropion (; ). However, the effects of naltrexone on methamphetamine-induced sleep disturbances have not been previously investigated. This is particularly important given the conflicting evidence suggesting that naltrexone might impair () or promote () sleep, depending on the subjects’ drug use history (e.g. alcohol use disorder vs naïve). In this regard, we have shown that naltrexone administration to naïve monkeys results in improvement of actigraphy-based sleep parameters (), raising the possibility that modulation of the opioid receptor system may reduce or reverse methamphetamine disruption of sleep. Therefore, the present study aimed to investigate the effects of acute naltrexone on sleep following methamphetamine administration in a nonhuman primate model. Four adult male rhesus monkeys () weighing 10–16 kg served as subjects for these studies. Subjects were experimentally naïve prior to the beginning of the studies. Monkeys were housed individually, but had visual, auditory and olfactory contact with other monkeys throughout the study, as well as access to chew toys and a mirror in their cage. Subjects were maintained on a 12h light/12h dark cycle with lights on at 0600 h (Zeitgeber Time 0, ZT0) and off at 1800 h (ZT12) and at a temperature of 21 ± 1°C. Water was available and monkey diet available once/day, supplemented by fresh fruit and forage (seeds and dried fruit). Subjects were weighed monthly during physical examinations. All of the procedures and animal maintenance were in accordance with the Guide for the Care and Use of Laboratory Animals (), with review and approval via the Institutional Animal Care and Use Committee of the University of Mississippi Medical Center.