article_snippet: This gives hope to the hundreds of thousands of people who suffer chronic migraines - the most debilitating type of headaches.
article_snippet: chronic migraine patients suffered headaches.
article_snippet: The International Headache Society defines chronic migraine as more than 15 headache days per month over a three-month period - more than eight migrainous – if The International Headache Society has been ruled out that the headaches are caused by an overuse of medication.
article_snippet: A migraine is severe recurring headache, usually affecting only one side of the head, characterised by sharp pain and often accompanied by nausea, vomiting, and visual disturbances.
article_snippet: According to the World Health Organisation (WHO), up to four per cent of the world's adult population have headaches on 15 or more days every month.
article_snippet: the World Health Organisation (WHO), up to four per cent of the world's adult population has identified chronic migraine as more disabling than blindness, paraplegia angina or rheumatoid arthritis.
article_snippet: the World Health Organisation (WHO), up to four per cent of the world's adult population has also categorised migraine at the same level of disability as dementia, quadriplegia and acute psychosis.
article_snippet: And people with migraines or severe headaches are three times as likely to become depressed than healthy individuals, the WHO warns.
article_snippet: This can lead to sufferers often becoming depressed and unable to cope, says the charity The Migraine Trust.
article_snippet: He said: 'If you have 15 days or more and you're just chasing the headaches it's not a good strategy.
article_snippet: Wendy Thomas, chief executive of The Migraine Trust, said: 'Many chronic migraine patients find existing treatments are ineffective, or cause unpleasant side effects.
article_snippet: Due to the way and how long sufferers are affected, people with chronic migraine take considerably more time off work, school, leisure, housework and social activities than episodic migraine patients.
article_snippet: Efficiency is also hit, with work or school productivity more than halved - described as a migraine 'hangover' by numerous sufferers.