At times, the sadness comes. But, Patti Zapp said, she knows that seeing her twins off to college a few weeks ago was just one of those milestones so many families go through.

On the plus side, she added, "I don't have so many towels to wash."

Saying good-bye to the youngest child can mean different things to different people. Some families view the empty nest with happy anticipation: Free at last!

Most experience a combination of sadness, anxiety and hope for their child as he or she heads off to college or a new role in the work force.

If the kids were heavily involved in sports or other activities beyond school, there can be a huge adjustment for parents who spent much of their free time at games or concerts.

"It's really quiet," said Mrs. Zapp, who coordinates the international baccalaureate program at Upper St. Clair High School.

"But right now, it's so new, it's almost like they're off at camp."

"Everyone has heard the term 'empty nest syndrome,' and they kind of shrug it off, like it's no big deal," said Joseph Greenberg, a psychologist who practices in Mt. Lebanon.

"They don't understand how much of a struggle it can be."

Mrs. Zapp and her husband, Ron, are dealing with a double whammy. Their children, who graduated from Bethel Park High last spring, went off to college at the same time.

Karen is at Kent State University, David, at Edinboro University.

"It's sort of uncharted territory," Mrs. Zapp said. "Most people learn with the first one and then deal with the last."

Unlimited calling through the family wireless plan helps, and the twins have Facebook pages that make "talking" to each other easier.

Still, there is a certain finesse in dealing with the issue of keeping in touch, Mrs. Zapp said.

"I waited last night for my daughter to call. I think it's important for them to help us set the parameters as to how our relationship will grow into an adult relationship."

Monica Gatchie's sons, Joseph and Jim, are in their early 30s. Her daughter, Jenna, graduated from South Allegheny High School and is a freshman at Clarion University this fall.

"Jenna came and now she's gone," said Mrs. Gatchie, of Glassport.

It's still early in the away-at-school process, she said, so they talk quite a bit each day on the phone.

"She calls me in the morning and I make sure she's up. I don't want to get her too used to that," Mrs. Gatchie added with a laugh.

"Parents can call and e-mail, but they don't want to overwhelm their child with 100 phone calls in the first 15 hours," Dr. Greenberg said.

For parents, coming home to an empty nest can be troubling.

"You come to the realization that she's probably never going to live here any more," said Mary Crowley, whose daughter, Laura, is a Penn State freshman via Mt. Lebanon High School.

"She'll be back for the summers, and for breaks, but once she goes to college and graduation, she'll probably not want to live here any more.

"Of course, she's always welcome to come back."

She and her husband, Jim, have a son who graduated from the University of North Carolina in December and works in Chicago.

"But this is different, because it's the last one," Mrs. Crowley said.

"I think because she's a girl, you hate to say it's different, but it really is. Still, it's nice. I'm enjoying it because I know she's OK up there and we have given her all the tools she needs, and she's happy."

Amy Leasure of Mt. Lebanon said she's not convinced having kids away at school means seeing them that much less.

The blended family she created with Frederick Leasure almost 12 years ago has had four sons keeping everyone on the run.

Joshua Leasure, 23, is in graduate school at Bucknell University. Christopher Tissue, 22, is a graduate of Denison University and working in Washington, D.C.

They have a brother, Zachery Leasure, who is a sophomore at Mercyhurst College, and Jeffrey Tissue just began his freshman year at Cornell.

"I don't think there is a huge difference in hours of the day you spend with them, because once they hit high school, you only see them for two hours a day.

"I learned that even when they do go to college, they are home an awful lot on breaks and you get all day with them.

"The summers are even longer than in high school, and they could be home for four or five weeks on [other] breaks.

"You really rack up the hours." Mrs. Leasure said.

The anticipation of the last child leaving the nest, she said, "was much worse than actually going through and living it.

"I would be much sadder if our children were not where they are."

And sometimes, the nest is almost full again. Corey Polena and her husband, John, recently sent their daughter, Erin, off to Sewanee University in Tennessee.

"For the first time in 22 years, I have not had someone heading off to the local schools, so it's unusual for me," said Mrs. Polena, a former PTA/PTO council president in the Mt. Lebanon School District.

But just as Erin headed out the door, back came her three older brothers. John, 27, an attorney, is living at home to help pay back loans from the University of Pittsburgh law school.

Mark, 24, an Allegheny College grad, is living at home and working to save. Scott, 22, is taking a year off from his studies at John Carroll University.

"At first, it was like, 'Oh lord, people are returning,' " said Mrs. Polena, "but it's been fun, seeing all of them relating to each other as adults.

"For Erin, it's been kind of nice. She got to spend more time with them than if it had been the traditional everyone-abandon-ship."

First Published: September 4, 2008, 8:00 a.m.