One in six psychotherapists have admitted they have tried to help 'cure' clients of their homosexual desires, according to a new UK study.

"There is very little evidence to show that attempting to treat a person's homosexual feelings is effective and in fact it can actually be harmful," explains researcher Michael King of University College London.

Treating homosexuality as an illness was still common in the 1970s and '80s, with tactics including pairing up erotic homosexual imagery with an electric shock punishment. The World Health Organization removed homosexuality from it list of illnesses in 1992, and so-called gay-to-straight 'conversion' therapies have since been shown to be ineffective and dangerous.

King and colleagues also asked more than 1,400 therapists if they would now try to change a patient's sexual orientation if asked to do so. Only 4% said they would.