Carrie Fisher is doing ''exceptionally well'' following her recent hospitalisation.

The 56-year-old actress was taken to a medical facility last week following a bizarre performance on a cruise ship in the Caribbean - which saw her singing snippets of songs, slurring her words and chasing her dog - and had her medication for bipolar disorder adjusted and now her mother Debbie Reynolds says she is back on track.

She told People: ''She's had manic depression bipolar since she was 13. It's an illness, and she's doing much better.

''I'm very proud of her, and she's doing exceptionally well. She'll be just fine, just great, and continue her writing as she always does.''

Debbie, 80, also spoke of how difficult bipolar disorder is for suffers to deal with, particularly when their behaviour is misinterpreted.

She said: ''[It's] really dreadful, and you are so alone because you're criticised, and people think you're doing it on purpose, and that you're misbehaving or having a spell because you want attention.

''It's not true. It's extremely difficult for everyone to deal with.''

Carrie's erratic behaviour on board the Holland American cruise liner Eurodam caused concern among the audience, with some speculation she had been drinking or taking drugs.

One guest on the cruise, Chris Smith, said: ''She clearly had trouble remembering things. She tried to tell some stories about her parents and Hollywood, but was having a hard time.''