Australian actress/singer Olivia Newton-John has spoken out about her battle with depression, revealing she turned to therapy and medication to help face her problems.

The Grease star was plunged into a downward spiral after her then-partner Patrick MCDermott disappeared during a fishing trip off the coast of California in 2005, and Newton-John admits she sought professional help as she struggled to cope.

She spent three months taking anti-depressants, but weaned herself off the pills because she didn't want to become "dependent" on them.

Newton-John tells Britain's The Times newspaper, "I took them until I could see the light again and never did them again. I didn't want to become dependent on them. That's why I stopped... It was a difficult time and got me out of a hole."

The 64 year old also enrolled in therapy to help her deal with MCDermott's disappearance, adding, "(I have been) a few times... I needed it. It gives you the tools to help you heal and deal with things."

MCDermott eventually turned up alive and well in Mexico five years after supposedly drowning in the boating accident.