ENDING a friendship takes many forms: an ugly confrontation, a polite “I don’t think this is working out,” or just the fade-out with not returning phone calls or responding to e-mail.

Or it can be a simple click on your Facebook page.

As many know, it’s called “defriending,” a term that the New Oxford American Dictionary formally acknowledged this summer. But can technology mitigate the complicated emotions that are associated with a failed friendship? Maybe not.

“Emotionally, it can be the same as being dumped because it’s one-sided,” said Irene Levine, a psychiatry professor at the N.Y.U. School of Medicine. “While the defriender may have been grappling with the decision to defriend for some time, it comes out of the blue for the person defriended.”

This absence of body language, and the single-click immediacy of online sharing has created problems that have no ready parallel offline.