“Many parents are befuddled by this,” said Debbie Pincus, a psychotherapist in Larchmont, N.Y. “They feel in the dark. On the surface, there has been no rupture.”

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For parents of children in their 20s, estrangement can sometimes result from clashing needs. Newly retired parents with more time on their hands may yearn for a closer connection with their son or daughter.

Meanwhile, the 20-something’s life is getting more hectic by the day.

“They’re beginning to develop their own relationships and establish their own life,” Pincus said. “If the recently retired parent feels more emptiness, they tend to lean on their adult child at a time when that child wants to stand on their own two feet.”

Creator of “The Calm Parent AM & PM” training program, Pincus urges parents to detach themselves from the situation rather than personalize it.

“Otherwise, you may feel anxiety and hurt, which can lead the adult child to turn away even more,” she said. “Stepping out of it helps you manage it.”

If you’re unsure why your child has severed contact, brace for a potentially long wait to find out. Searching for quick answers may prove fruitless.

In some cases, an adult child may prefer not to share adverse news with a parent, Pincus says. Examples include substance abuse, politically different or extreme beliefs, divorce or job loss.

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“Estrangement may stem from adult children making choices that the parent wouldn’t easily accept—choices that don’t accord with the parent’s way of thinking,” she said. “It’s more about how enmeshed we are with each other” that sets the stage for conflict.

Parents with controlling personalities can make matters worse. If swirling anxiety affects how they relate to their son or daughter, it can morph into unwelcome intensity that upends the relationship.

Anxious parents confront myriad worries:

Will my kid depend on me financially?

Can my kids survive on their own?

Why aren’t they making the right career or relationship choices?

“An adult child will try to move away from all that,” Pincus said. “Then you get into a reactive cycle” where the parent frets even more and the estrangement grows.

She advises parents to replace feelings of anxiety with a calmer, more reflective mind-set. Instead of reacting impulsively, step back and ask yourself, “What can I say or do?”

If you decide that you’re increasingly upset that you’re still paying your kid’s rent, for instance, weigh your options.

Pincus suggests saying to yourself, “Let me rethink what I’m willing to do and not do.”

It’s natural to seek a clear explanation for estrangement. But it’s often the emotional baggage carried over decades, not a single event, that drives families apart.

“It’s likely that the patterns growing up and the dependencies that have taken place” ultimately contribute to estrangement, Pincus says.

Trying to isolate the reason for estrangement presents other obstacles. Parents and children may see two vastly different realities as the backdrop for their relationship.

In researching estrangement between mothers and their adult children, Sarah Schoppe-Sullivan found that the mothers often attributed the conflict to external circumstances in the child’s life.

“The mothers thought it could be other family members turning the adult child against their mother or interfamily factors like divorce,” said Schoppe-Sullivan, a professor of psychology at Ohio State University. “Or they thought it could be a child’s addiction.”

But the adult child viewed the reason for estrangement through a different lens. They might see it as the result of their mother’s emotional abuse or neglect—or other toxic behaviors.

Schoppe-Sullivan recommends that parents reflect on the history of their relationship and then write a letter of amends to their child, even if they don’t think they’re solely to blame for the split.

“A sincere apology can work if you really understand what your child thinks,” she said. “But if the child has cut off contact, they can choose to ignore your letter. They are not obligated to be in a relationship with you. So just wait and see what happens.”

There are degrees of estrangement, Schoppe-Sullivan adds. Sometimes, a parent and child grow distant without a total cessation of contact.

“The estrangement can be intermittent,” she said. “Or it can be a progression of incidents that result in more distancing.”

To offset the hurt, parents can reset how and where they focus their mental energy. Dwelling on the anxiety and pain of estrangement can ruin your retirement years.

Pincus urges retirees to ask themselves, “How much time am I focusing on my adult child versus myself?” and “How much time am I managing my own life, goals and friendships?”

Shifting your attention to how you can maximize your retirement—by pursuing wide-ranging interests and investing in other relationships—can help you achieve more balance and emotional stability. While the estrangement may linger, your ability to reconcile increases if you’re finding more fulfillment in other aspects of your life.