The 23 year old was allegedly placed on involuntary psychiatric hold on Thursday (16Jul09), after suffering a meltdown and calling cops to her Los Angeles home the night before.

A spokesperson for the former The O.C. star has confirmed Barton received help for a "medical issue", but has refused to comment further.

The silence prompted claims Barton had been hospitalised after feeling "suicidal" following three days of hard partying.

A source told the New York Post's gossip column PageSix, "She's in very bad shape. She's running out of money and can't find love, so now she is looking for a good time to escape her misery. She is on a downward spiral. She is a mess. She is a suicidal, uninsurable mess.

However, Barton's rep has slammed the drug claims, telling OK! magazine the reports are "completely preposterous".

The denial follows reports the star's mystery illness has pushed back production on her new TV programme The Beautiful Life, which was scheduled to begin on Wednesday (22Jul09).