Lindsay Lohan feels ''whole again'' after rehab.

The troubled actress completed 90 days of court-ordered treatment for substance abuse earlier this month and insists her latest stint in rehab has changed her life for the better.

In a highly publicised interview with Oprah Winfrey's talk show 'Oprah's Next Chapter', which aired on US TV last night (18.08.13), she said: ''I feel whole again and I have such a desire to want to keep this feeling and stay this way, and I'm willing to do whatever it takes.''

The 27-year-old star further claimed she was in a ''different head space'' since her stay at the Cliffside Malibu treatment centre in California, and has vowed to stay ''present and clear-headed and focused'' now that she is out of rehab.

Grilled about what she is taking these days, Lindsay asserted to Oprah she only takes ''vitamins'' and a prescribed drug called Nexium, which is used to treat acid reflux.

The 'Mean Girls' star candidly admitted a past addiction to alcohol, which she says ''was a gateway to other things for me'', and owned up to using cocaine around 15 times.

As well as the interview with Oprah - which was filmed just days after she left rehab - Lindsay will star in an eight-part reality series for the talk show host's OWN network next year.