DEAR ABBY: My 19-year-old son, who is on the spectrum but high-functioning, has left home. He’s legally an adult but wouldn’t allow me to teach him normal survival skills, such as balancing a checkbook, paying with a debit card, etc. He knows very little about the world; he learns from his online friends.

It has been four months, and he has now changed his phone number and won’t call, email or text. He moved across the country to live with an online friend. I’m very concerned about him. What should I do? I don’t email him often, but when I do, I just tell him I love him, and I never say anything negative. — LOST IN CALIFORNIA

DEAR LOST: Four months, you say? Assuming you have his current address, perhaps it is time for you — and his other parent, if he or she is in the picture — to pay the young man a visit to see how he’s doing. Because he won’t respond to phone calls, emails or texts, I don’t think you have a choice other than that.

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Dear Abby is written by Abigail Van Buren, also known as Jeanne Phillips, and was founded by her mother, Pauline Phillips. Contact Dear Abby at www.DearAbby.com or P.O. Box 69440, Los Angeles, CA 90069.