A TYPE of drug prescribed for Parkinson's disease can cause some patients to become compulsive gamblers or sex addicts.

Researchers reported on 11 patients who acquired an irrepressible urge to gamble after taking dopamine agonist drugs.

One lost £115,000 in six months.

Six other patients developed problems, including compulsive eating, increased alcohol consumption and an insatiable appetite for sex.

A number became fixated on pornography, pestered their partners for sex, or had affairs.

Doctors in the United States traced the problems to dopamine agonists, drugs that mimic the effect of the brain chemical dopamine.

Parkinson's patients have reduced levels of dopamine, a chemical that relays messages between brain cells.