Americans are set to change their clocks back to standard time overnight on Sunday, which some doctors say should be permanent.
"Fixed national time is the best option as it most closely matches the human sleep-wake cycle," said New York-based clinical psychiatrist Yalda Safai in an email to ABC News. "Any changes to the body's natural circadian rhythm has the potential to disrupt the natural functioning of the body."
Right now, the majority of the United States "springs ahead" in the spring, setting the clocks forward by one hour, so that there's more light later in the day. "Falling back" to standard time leads to more light in the mornings.
But experts are calling for permanent standard time year-round. The American Academy of Sleep Medicine (AASM), for example, has formed a new coalition to advocate for state and federal legislation making standard time permanent across the U.S. Other organizational members include the National Sleep Foundation, Save Standard Time, Sleep Research Society, and Society for Research on Biological Rhythms.
National, year-round standard time aligns best with the natural day-to-night rhythms of the human body, so sticking to it benefits public health, experts say.
"Having more light in the mornings is beneficial," said Rebecca Robbins, PhD, an assistant professor at Harvard Medical School and scientist at Brigham and Women's Hospital says to ABC News, "Some positive evidence we've seen from switching to standard time is having more sunlight exposure so our children can safely walk and wait for the school bus. Morning sunlight exposure stops the floodgates of melatonin, our sleep hormone, and switches to the wake phase of our circadian rhythm. This is important for our brain to say we can start our day."
But shifting the clocks back and forth has health repercussions, experts say.
The shift in time has been associated with increased heart attacks, strokes, abnormal heart rhythms, sleep disruption, mood disturbances, and even suicide, according to research published in the Journal of Clinical Sleep Medicine. "The rate of stroke rises 8% [in the spring], which is substantial," says Dr. Leah Croll, a neurologist and assistant professor at the Lewis Katz School of Medicine at Temple University."
AASM describes the change in time as a means of developing chronic "jet lag." The body's innate clock and the environmental clock don't align.
"Sleep is essential for promoting cardiovascular and neurological health. Those who are sleep deprived experience headaches, brain fog, memory and concentration issues, and do not make good decisions for themselves because executive function is not at its best," says Croll.
While the changes can be an inconvenience for most, those with anxiety, depression, bipolar disorder, seasonal affective disorder and other mood disorders are much more negatively impacted by time changes, experts say.
Dr. Judith Joseph, board-certified psychiatrist and researcher at NYU Langone Medical Center, and chair of Women in Medicine at Columbia University Vagelos College of Physicians and Surgeons, told ABC News, "Sleep is very crucial in stabilizing mood. Those individuals experience more disruptive mood changes with regards to that shift. They're more sensitive and more vulnerable."
Experts say there are some ways to stay healthy while preparing for the clock change. Frequent walking and exercise can help reset circadian rhythm and be a mood booster. Limiting screen time and seeking therapy can improve sleep hygiene.
"If you know there's going to be a schedule change, then start preparing a week in advance, by changing that routine 10 minutes every day. Go to bed earlier and shift your schedule slowly," Joseph says.
She added, "If you have a history of anxiety and depression, or bipolar depression or seasonal affective disorder, schedule more frequent therapy sessions because you'll need more support. Don't be hard on yourself and be very real about it. If you have these vulnerabilities and risk factors, be proactive by planning your support ahead of time."
Dr. Avish K. Jain, DO is a resident physician at Cooper University Hospital, and is a medical contributor to the ABC News Medical Unit.