Johnny Depp has turned his back on alcohol after declaring, "I pretty much got everything I could get out of it".

The movie star, who played hard-drinking pirate Captain Jack Sparrow in the Pirates of the Caribbean films, insists he has been sober and alcohol-free for 18 months after years of enjoying fine wines and spirits.

He tells Rolling Stone magazine, "I investigated wine and spirits thoroughly, and they certainly investigated me as well, and we found out that we got along beautifully, but maybe too well.

"I don't have the physical need for the drug alcohol. No, it's more my medication, my self-medication over the years just to calm the circus. Once the circus kicks in, the festivities in the brain, it can be ruthless.

"I'm able to continue (drinking) for great periods of time, weirdly. For weeks. There's no great point to it, ultimately. You realise that you wouldn't treat your car that way."