Tips for moms who struggle with back-to-school sadness

— -- The last group of children head back to school this week and judging from the celebratory posts and memes on social media, it may seem like every mother is overjoyed to be free of her children for a few hours each day.

But not every mom is joyful this time of year. In fact, many deal with feelings of sadness and anxiety when their children return to school.

"The start of school can often trigger extra reflection on how quickly time passes and how much things change," Jill E. Daino, a social worker and New York City-based therapist told ABC News. "Time is one of many things we have no control over so whether someone is ready or not the start of the school year is here. For some moms whose identity is profoundly shaped by being a mom the start of a new school years marks another step in that child's move toward independence."

Mom Mia Carella of the site ThisMomWithaBlog.com shared on Facebook her struggles with her daughter's first days of first grade.

"They said it would get easier. They said last year would be the hardest, being the first time and all," she wrote. "They said this year would be better; that I'd be happy to see her go back to school after a long summer. Nope."

She told ABC News, "Social media is full of posts from parents so excited for their kids to head back to school, but I know I am not alone in how I am feeling. I think it is perfectly normal not to be jumping for joy at the bus stop. If you are, that's great. And, if you are like me, that's OK, too. I wanted to put that out there in my post and let other parents know their feelings are normal."

Carella's daughter was born with a congenital heart defect and has some developmental delays, she said. But the feelings she expresses are not specific to mothers of kids with additional needs, experts say.

"Most of my clients are moms and many of them experience sadness and anxiety around their children growing up," Limor Weinstein, a mental health counselor and parent coach told ABC News. "Many moms are attached to their kids and have a challenging time separating from them. The separation anxiety issue that so many children experience when leaving their parents is sometimes just as prevalent with moms. This is natural."

"Letting our hearts - our whole worlds - walk out into the world alone without us is never easy," Carella wrote in her post. " We have to trust that the world will treat them as we would. Trust that they will have everything they need. Trust that we can loosen our white-knuckled grip that we think is holding everything together, and let them go."

Weinstein said anxiety can surface this time of year.

"Anxiety can also manifest itself in fears for your child, a fear that something bad will happen to them that you can’t protect them from," she said. "Other seemingly unrelated factors can also contribute to this anxiety and sadness. If you have a general feel of losing control in other areas of your life, your kids going back to school could exacerbate that."

She also said a therapist who practices Cognitive Behavioral Therapy and positive psychology can be helpful for mothers.

Daino echoed the need to reach out to friends and family. "Often women can feel alone with these feelings if they perceive themselves as the only ones. So to have a supportive, nonjudgmental person in their life is important. At the same time, as a therapist I would want to help them begin to understand what their particular feelings are about bc it will have unique aspects for each individual."

As for Carella, whose daughter started school a few weeks ago, she said her daughter is happy at school and every day gets easier. Still, she wants other parents to know she understands their feelings well.

"Let them grow," she wrote in her Facebook post. "But, it is hard - one of the hardest things I've ever done. To all the moms and dads having trouble letting go this year, you are not alone. So, so not alone."