A groundbreaking clinical trial led by researchers at Mass General Brigham has revealed that the wake-promoting medication solriamfetol significantly improves alertness and overall daily functioning for individuals working early morning shifts. The study, published in the prestigious journal NEJM Evidence, represents the first clinical trial specifically targeting the unique challenges faced by workers whose schedules begin in the pre-dawn hours—a demographic that constitutes the largest segment of the non-traditional workforce yet has remained largely unstudied in sleep medicine.
Shift Work Disorder (SWD) is a chronic condition characterized by excessive sleepiness during work hours and insomnia when attempting to sleep during the day. While much of the existing research on SWD has focused on overnight or "graveyard" shift workers, the Mass General Brigham team identified a critical gap in the medical understanding of those who start their workdays between 3:00 a.m. and 7:00 a.m. These individuals, ranging from healthcare providers and first responders to transportation workers and bakers, often face severe biological misalignment that compromises their safety and long-term health.
The Biological Conflict of Early Morning Labor
The human body is governed by a circadian rhythm, a 24-hour internal clock regulated by the suprachiasmatic nucleus in the brain. This biological timer dictates cycles of alertness and sleepiness, primarily influenced by light exposure. For the average person, the hours between 3:00 a.m. and 6:00 a.m. represent the "circadian trough," a period when core body temperature is at its lowest and the drive for sleep is at its physiological peak.
When workers are forced to wake and perform complex tasks during this window, they are operating against millions of years of biological evolution. "People who start work between 3 a.m. and 7 a.m. are waking up at a time when the brain is biologically programmed to sleep," explained first author Kirsi-Marja Zitting, PhD, an investigator with the Division of Sleep and Circadian Medicine at Mass General Brigham. "That makes staying alert extraordinarily difficult, even when they are highly motivated."
The study highlights a "double burden" inherent to this schedule: workers must combat extreme somnolence during their shift, but by the time they finish work and attempt to rest, the rising sun and increasing environmental noise often make restorative sleep impossible. This cycle leads to a cumulative sleep debt that traditional caffeine consumption often fails to mitigate.
Methodology of the Clinical Trial
To address this issue, the research team conducted a randomized, double-blind, placebo-controlled trial involving 78 participants. All participants were adults diagnosed with Shift Work Disorder who regularly worked early morning shifts starting between 3:00 a.m. and 7:00 a.m.
The trial spanned four weeks, during which participants were randomly assigned to receive either a daily dose of solriamfetol or a matching placebo. Solriamfetol, marketed under the brand name Sunosi, is a dopamine and norepinephrine reuptake inhibitor (DNRI). Unlike traditional stimulants that may cause a "crash" or significant jitters, solriamfetol is designed to provide sustained wakefulness. It is currently FDA-approved for the treatment of excessive daytime sleepiness associated with narcolepsy and obstructive sleep apnea.
Researchers employed the Maintenance of Wakefulness Test (MWT) to objectively measure the drug’s efficacy. During this test, participants are placed in a dark, quiet, and comfortable environment and instructed to resist sleep. This setting simulates the low-stimulation environments that often prove most dangerous for sleepy workers, such as long-distance driving or monitoring medical equipment. Additionally, the trial utilized the Clinical Global Impression of Change (CGI-C) scale, allowing both clinicians and participants to rate improvements in overall functioning and quality of life.
Key Findings: Enhanced Alertness and Safety
The results of the four-week trial were statistically significant and clinically meaningful. Participants taking solriamfetol demonstrated a marked increase in their ability to remain awake during the MWT compared to the placebo group. On average, those treated with the medication were able to stay alert for significantly longer durations during hours that matched their typical work shifts.
Beyond objective laboratory measurements, the subjective reports from participants and clinicians were equally compelling. Workers reported:
- Improved concentration and mental clarity during the first several hours of their shifts.
- A greater ability to complete complex tasks without the "brain fog" typically associated with early rising.
- Enhanced safety during the morning commute, a period when the risk of microsleeps and fatigue-related accidents is highest.
"The improvement we saw is clinically meaningful," said senior author Charles A. Czeisler, PhD, MD, chief of the Division of Sleep and Circadian Medicine at Mass General Brigham. "These workers were able to stay awake and alert throughout a full eight-hour shift, which has real implications for performance, safety, and quality of life."
One of the most notable aspects of the findings was the drug’s limited impact on subsequent sleep. Unlike some wake-promoting agents that can linger in the system and cause insomnia when the worker finally has the chance to rest, solriamfetol appeared to provide alertness during the shift without significantly degrading the quality of the participants’ daytime or evening sleep.
The Economic and Societal Impact of Shift Work Disorder
The implications of this study extend far beyond the laboratory. Shift work is an essential pillar of modern society, with approximately 20% to 25% of the global workforce operating outside standard daytime hours. However, the "hidden biological cost" of this necessity is staggering.
According to data from the National Safety Council, tired workers cost U.S. employers approximately $136 billion annually in lost productivity. More critically, sleep deprivation is a leading factor in workplace accidents. In industries such as healthcare, the stakes are even higher; fatigued residents and nurses are significantly more likely to commit medication errors or suffer needlestick injuries.
The transportation sector is perhaps the most vulnerable. Early morning hours see a surge in freight delivery and public transit activity. A driver experiencing the symptoms of Shift Work Disorder is biologically equivalent to a driver with a blood-alcohol level above the legal limit. By proving that solriamfetol can effectively bridge the gap between biological sleep drive and professional requirements, the Mass General Brigham study offers a potential pathway to reducing the frequency of fatigue-related catastrophes on the road and in the workplace.
Chronology of Treatment for Shift Work
The history of treating SWD has been characterized by a gradual shift from general stimulants to targeted wake-promoting agents. In the late 20th century, caffeine and amphetamine-based medications were the primary tools used to combat work-related sleepiness. However, these often came with cardiovascular side effects and a high potential for dependency.
In the late 1990s and early 2000s, modafinil and its successor, armodafinil, were introduced. These drugs were a major step forward, offering wakefulness with fewer peripheral side effects. However, most clinical trials for these medications focused exclusively on overnight workers. The 2024 publication of the solriamfetol trial marks a new chapter in this chronology, finally acknowledging the "early riser" as a distinct clinical demographic with specific needs.
Future Research and Regulatory Outlook
Despite the positive results, the researchers cautioned that the study was limited in duration and scope. The four-week trial involved otherwise healthy adults, meaning the long-term effects of daily solriamfetol use for SWD remain unknown. Potential concerns such as the development of tolerance or long-term cardiovascular impact require further longitudinal study.
The Mass General Brigham team is already moving forward with the next phase of research. They are currently enrolling participants for a follow-up clinical trial that will evaluate solriamfetol’s efficacy specifically in overnight shift workers. If these subsequent trials yield similar results, it could pave the way for solriamfetol to receive formal FDA approval for the broad treatment of Shift Work Disorder, expanding its current indications.
"Shift workers are essential to how our society functions," Czeisler emphasized. "From the people who stock our grocery shelves before dawn to the doctors who take over at the change of a shift, we rely on them. This study shows we can do better for them by providing evidence-based treatments that respect their biology while supporting their work."
Conclusion: A New Standard for Occupational Health
The findings published in NEJM Evidence suggest a shift in how occupational medicine should approach the early morning workforce. By recognizing that a 4:00 a.m. start time is not merely "starting the day early" but is a significant disruption of human physiology, clinicians can better identify and treat those at risk of Shift Work Disorder.
As the global economy increasingly demands 24/7 operations, the integration of wake-promoting therapies like solriamfetol could become a standard component of occupational health and safety protocols. For the millions of workers who wake up while the rest of the world is still in deep sleep, this research offers more than just a medication; it offers a scientific validation of their daily struggle and a tangible hope for a safer, more alert professional life.
The study was supported by funding from Jazz Pharmaceuticals, Axsome Therapeutics, and the Brigham and Women’s Hospital Center for Clinical Investigation. As the medical community awaits the results of longer-term trials, the current data stands as a definitive step toward mitigating the risks of one of the most common, yet overlooked, work schedules in the modern world.
