STAR WARS star CARRIE FISHER’s meltdown of TITANIC proportions lands her in the psych ward!

CARRIE FISHER suffered a manic episode on a cruise, and The ENQUIRER has learned that her bizarre behavior landed her in a psych ward!

The 56-year-old “Star Wars” icon – who’s been diagnosed with manic depression and bipolar disorder and has also battled booze and drugs for more than 20 years – reportedly went swimming fully clothed.

Then she showed up for a performance on the RSVP Cruise of the Caribbean “trashed and incoherent” in front of a packed house on Feb. 17.

“Carrie was a hot mess!” a source on the Holland America Eurodam ship told The ENQUIRER.

“The poor thing must have been off her meds and was all over the map trying to crack jokes and remember song lyrics.

 “At one point her little dog joined her in the spotlight and took a big poop on stage! It was funny and tragic at the same time.”

The star’s publicist, Carol Marshall, confirmed there was a “problem” on the ship.

“But Carrie was not on anything,” Marshall told The ENQUIRER. “No substances were involved. She wasn’t drinking. It was a medical incident.”

Fisher, who shared her troubles in her memoir “Wishful Drinking,” was taken to the Resnick Neuropsychiatric Hospital at UCLA and treated for three days before being released on Feb. 25, Marshall said.

“There’s no quick fix for bipolar disorder,” Marshall pointed out. “Every now and then it happens when her meds are off.”

“Carrie is now home and feeling much better.”