Compulsive sex behavior has been classified as a mental illness for the first time.
Its inclusion on the International Classification of Diseases list marks a turning point in the way people who present with sex addiction will be treated.
Dr. Valerie Voon, from the Royal College of Psychiatrists, said between two and four percent of the United Kingdom population suffer from compulsive sex behavior.
WHO's list describes sex addiction as a "persistent pattern of failure to control intense, repetitive sexual impulses or urges resulting in a repetitive sexual behaviour".
"Adding this to the World Health Organization list is an excellent step for patients as it allows them to recognize that they are suffering with a problem - it takes it out of the shadows and they are able to seek help for it".
"It allows them to recognise that they are suffering with a problem".
"It is a behaviour that tends to be hidden as it's shameful and often sex addicts don't come forward".
Ammanda Major, of the relationship charity Relate, also welcomed the move.
She said: 'People need to understand this doesn't mean every child who spends hours in their room playing games is an addict, otherwise medics are going to be flooded with requests for help'.
"This often negatively impacts on their lives as well as on the mental health and wellbeing of their partners and families". It's important that the necessary funding is made available to support anyone affected by these issues. It has been included on the same list as sex addiction.
It is unclear if this move will lead to sex addiction treatment being provided on the NHS, which does not now consider it to be a condition.
The move comes after the worldwide body also declared that compulsive video-game playing is a disorder.