After some 18 months of remote work, more and more companies are bringing their employees back into the office.

Many workers have mixed and complicated feelings about the change.

“Returning back to the office may feel like culture shock,” said Debra Kaplan, a therapist in Tucson, Arizona.

Adding to the stress is all the remaining uncertainty. As the pandemic proves hard to shake, companies keep pushing back their return dates, and many haven’t come out with mask or vaccination policies.

“I’m more frustrated with unclear or difficult-to-find information than I’m anxious about getting sick with Covid again,” said Emily, a New York college professor who also asked to use her first name only.

“And I’m anxious that, at some point during the semester, the school will have to shut down entirely.”

CNBC spoke with therapists about how people can deal with the change.

“In the absence of concrete information, [the brain] will fill in the blanks with ‘what ifs,'” Kaplan said. “That leads to a hamster-wheel of obsessional thinking.”

To avoid that spiraling, try to learn as many details as possible about your company’s return-to-work plans, she said. “The simple act of getting answers, to the extent possible, will calm our brain.”

If certain information isn’t readily available, you may need to speak to your manager, according to Kaplan. “I suggest that those who have concerns share directly what their concerns are,” she added.

Should something still be bothering you, think of what would make you feel better.

“Offer a suggestion so that a resolution potentially meets your needs,” Kaplan said.

To avoid any big surprises on your first day back, Lisa Baranik, assistant professor of management at the University at Albany, recommends people visit their office ahead of their official return date. (If that’s allowed, of course.)

Employees may find that their desk, or the cafeteria, is in a new place or that technology has been updated.

In addition, Baranik said, think through your first day and make decisions in advance. “What will you wear?” she said. “What will you do for lunch? Preparation will help the transition go smoothly.”

Some anxieties about returning to work may be less rational, said Keith Miller, a social worker in Washington, D.C.

That doesn’t mean they should be dismissed.

“Some responses to change can be childlike,” Miller said. “Extend compassion to this young part of you.

“Maybe, for example, you discover a too-irrational-for-any-adult fear of wearing shoes all day,” he added. “But, if you meet that fear with compassion rather than irritation, perhaps all it wants is to have permission to take your shoes off at the office.

“So, you make an accommodation for yourself.”

Introverts have especially enjoyed remote work, said Susan Cain, author of “Quiet: The Power of Introverts in a World That Can’t Stop Talking.” As a result, they may feel more apprehensive about being thrown back into an office with co-workers and bosses.

“To emotionally prepare, introverts should think about which aspects of working from home they’ve most appreciated, and consider how they can maintain these aspects in a new setting,” Cain said.

“Have they enjoyed taking walks throughout the day?” she added. “Often, this is possible in an office context, too; people just don’t think to do it, or feel vaguely guilty about stepping away.”

After so much time at home, some workers may struggle with being separated from their pets.

“To many people, having a pet is like a child,” Kaplan said. She recommends that pet owners, if they can afford to, hire a sitter or walker to feel that they’re still caring for their animals while they’re gone.

Others may want to get a home camera, she said. “The visual connection reassures the pet parent that their loved one is safe and likely snoring away on the couch, comfortably awaiting the pet parent’s return.”

Mark Gerald, a psychoanalyst in Manhattan, encourages people to focus on what they’ll be gaining by returning to the office.

“Being part of a community, an organization, learning more about oneself and others from more intimate teamwork, are essential values of being part of the world,” he said.

At the same time, he said, it’s OK to grieve for your pandemic routine.

“For those who were less happy with the job, its commute or the formality of uniform appearance, work became a new, more flexible and integrated part of life,” Gerald said. “For many in this cohort, the prospect of going back to the office involves a significant element of loss.”