Los Angeles - Miley Cyrus has compared Sinead O'Connor to Amanda Bynes.
The starlet hasn't responded well to the open letter the Irish hitmaker penned on Thursday, in which she warned Miley her provocative behaviour and scantily-clad performances would leave her "prostituted" by the music business.
The former Hannah Montana star has taken to Twitter to slam Sinead, poking fun of her mental health and likening her to troubled actress Amanda, who has spent the summer in a psychiatric hospital.
She wrote, "Before Amanda Bynes.... There was...", attaching a screenshot of a tweets from an account she believed was Sinead's, clamouring for psychiatric help.
While the account was a fake, Sinead did post suicidal tweets in 2011 and has struggled with mental illness in the past.Doesn't need shocking theatrics
Miley also shared a photo of Sinead's 1992 controversial Saturday Night Live
appearance, when she ripped up a picture of the Pope.
The 46-year-old singer's posting on her official website came in response to Miley's claims she based the video for ballad Wrecking Ball
- in which she is seen licking a sledgehammer and writhing around naked - on her own 1990 stripped-back hit, Nothing Compares 2 U
Sinead pleaded with Miley to stop sending a "dangerous" message to her female fans and insisted she doesn't need shocking theatrics to be successful because she has too much "talent".
Miley has been on a mission to shed her child star image of late and caused outrage by twerking in a latex bikini while rubbing herself with a foam finger at the MTV Video Music Awards in August.