Or was it the end of "Cheers" that did you in, when Sam and Carla disappeared from the screen.

If so, you are not alone. You suffer from what researchers call TV trauma, a form of mourning that sets in among some people when a favorite TV series goes off the air.

And it's not at all a rare disorder. More than 20 percent of people develop deep attachments to TV characters, only to suffer when the shows end, and it's even more common among 16- to 24-year-olds. About one in three are afflicted, according to a new study out of Britain.

“What we found most surprising was the sheer emotional impact that TV characters have on people in real life. These are fictional characters that Britons do take seriously in their real world. That is an amazing crossover from the realms of fiction to the world of reality,” says a spokesperson for Tiscali TV, the multi-channel television provider that commissioned the study.

That backs up the findings some years back by an evolutionary psychologist at Indiana University of Pennsylvania, Satoshi Kanazawa.

Kanazawa argued that because the human brain developed before television, it does not readily differentiate between real friends and TV friends. How would it really know? It assumes people with whom one has regular contact are most likely friends or relatives.

People who watch a lot of TV tend to believe they have more friends than those who are light watchers.

The new British study, which surveyed nearly 1,600, reveals just how much that is so.

One in three people said they looked forward to their favorite TV program more than anything else in their week. Some 13 percent regularly daydreamed about being in their favorite show, and that number rose to 40 percent among 16- to 24-year-olds.

Nearly one in three admitted to having fallen in love with a TV character. That number jumped up to 50 percent among 16- to 24-year-olds.

When a show does end, more than a quarter admitted to missing their favorite TV characters and 22 percent said it left a gap in their lives.

Tears are even shed. Some 31 percent of 16-to-24s say they cried extensively when a favorite show ended.

Writes David Lewis, a psychologist involved with the research: “When the character’s show ends, it can hit their fans as hard as losing someone close in the real world."

And the shows that generated the deepest feelings of loss? Most were American imports.

"Friends" ranked second, and fifth was "Sex and the City." "Cheers" was seventh, "West Wing" eighth, "The Sopranos" ninth and "The O.C." 10th.