The study found people taking these drugs were twice as likely to develop chronic migraine a year later as those who had not taken such drugs.
For the study, 24,000 people with headaches in the United States were surveyed about medications used for headaches. From this sample, the researchers selected those who had been diagnosed in 2005 with episodic migraine -- fewer than 15 days of headache per month. Chronic migraine is having 15 or more days of headaches a month.
Among those with episodic migraine in 2005, 209 people had developed chronic migraine in 2006.
"People who use drugs that contain barbiturates and opioids, if only for a total of seven to eight days a month, appear to significantly increase their risk of migraine progression," study author Dr. Marcelo Bigal of Albert Einstein College of Medicine, in New York, said in statement. "Strict limits for these types of drugs should be enforced among people with migraine as a way of preventing their migraines from becoming more frequent and more painful."
The findings were presented at the American Academy of Neurology Annual Meeting in Chicago.

