With shorter days and darker commutes, it’s no surprise that two in five adults say their mood shifts during winter months—which could negatively affect employee wellbeing and, in turn, workplace productivity and morale.

According to Lolly Coleman, director of provider quality and engagement at Rula Health, winter often causes dips in mood, energy and focus, making it essential for HR leaders to recognize early signs of Seasonal Affective Disorder (SAD). While many people are familiar with the “winter blues,” she explains, SAD is a more pervasive mood disorder tied to clinical depression symptoms.

According to Coleman, although research is ongoing to better understand the cause of SAD, scientists have identified factors that might lead to individuals developing symptoms:

• lower serotonin levels (which affects mood and emotions);
• a lack of vitamin D from less sunlight and food;
• increased levels of melatonin, which affects the sleep-wake cycle.

Coleman says in the workplace, SAD can impact work performance, from focus and productivity to social connection and team dynamics.

“Common symptoms an HR manager should look out for are team members who have trouble focusing on tasks, feel fatigued and sluggish,” she says. Also, they may have more difficulty with time management than usual, frequently oversleep or feel sad or unmotivated most of the day, almost every day.

See also: ‘Quiet firing’ and layoffs have workers ’emotionally drained and stressed’ heading into 2026

How to boost employee wellbeing—even in the winter

Coleman says there are proactive workplace strategies HR teams can employ to get ahead of these seasonal mood shifts, and this work should start today.

In the office, for example, employers can offer spaces with light therapy lamps when natural sunlight is unavailable, or schedule movement reminders throughout the workday, such as prompting employees to take walks. Finally, foster human connection by encouraging interactive meetings or team lunches.

It’s equally important for HR to help managers know when to encourage professional help and recommend evidence-based, covered care through virtual mental health platforms or in-person therapy, Coleman says.

For example, she explains, one type of therapy that can target symptoms of SAD and other forms of depression is cognitive behavioral therapy, which can reduce symptoms by helping identify and replace negative thought patterns.

“In fact, a study found that CBT was more effective at reducing seasonal depression than light therapy alone,” she says. Employers should make sure they allow for enough autonomy and flexibility in employee schedules to allow for therapy appointments or other wellness breaks throughout the day.

A larger conversation on employee wellbeing

On a broader scale, HR can help leadership be open to more flexible scheduling, along with increasing wellness check-ins with managers and peers and facilitating open conversations around mental health across the company.

She adds that HR can also help leaders should also model self-care to encourage the workforce to take employee wellbeing seriously. Things like listing breaks on their calendars or taking time to engage in a walk during the workday can show employees that wellness matters.

According to Coleman, whether it’s simply encouraging screen breaks to go on an afternoon stroll before sunset, or increasing one-on-one meetings to provide mental health resources, it’s important for HR to be cognizant of seasonal shifts in mental health.

“That way, they can help mitigate any SAD symptoms,” she says.