Catherine Yang

A new Yale study has shown that use of the prescription stimulant modafinil can reduce former cocaine addicts’ chances of relapsing, likely because of modafinil’s ability to improve addicts’ sleep.

Researchers studied 57 cocaine-dependent individuals while they were enrolled in an inpatient program and for six weeks afterwards in an outpatient setting. Study participants either received a placebo or 400 mg of modafinil — a mild stimulant drug often used to treat narcolepsy or shift-work-induced daytime fatigue. Compared to the group that received the placebo, cocaine addicts who received the 400mg of modafinil had more consecutive cocaine-free days during outpatient treatment and higher daily rates of abstinence. The study found that these protective effects were associated with increased slow-wave sleep, which modafinil promotes, suggesting that improved slow-wave sleep can help treat addiction.

“We found that treatment with modafinil, when started during a period of inpatient treatment, promotes abstinence over the next 6 weeks,” said Peter Morgan ’92, study co-author and professor of psychiatry at the Yale School of Medicine. “We also found that the effect of modafinil is mediated, at least statistically, by its slow-wave-sleep promoting effect.”

In order to study modafinil’s sleep-promoting effects on patients’ recovery outcomes, researchers measured participants sleep quality and quantity with polysomnographic sleep recording, a comprehensive recording of biophysical changes during sleep. Participants’ sleep was tested both before and after they began taking daily modafinil.

During the six weeks of outpatient treatment, researchers used urine toxicology tests to screen study participants for cocaine use. The group that received modafinil had a higher average percentage of cocaine-free urine tests than the placebo group did:52 percent cocaine-free tests versus 26 percent.

According to the paper, this result — namely that daily modafinil can help keep cocaine-dependent people from relapsing by improving sleep quality — points toward targeting sleep quality to help treat addiction.

“Slow-wave sleep is related to brain recovery,” said Vahid Mohsenin, study co-author and professor of pulmonary medicine at the medical school.

Morgan noted that sleep is “an essential body function” that has “evolved over eons to promote normal, healthy function.” The problems associated with poor sleep, including difficulties with decision making, learning and emotional regulation, could all impact someone’s ability to stop using cocaine, he added.

Up to 90 percent of cocaine-dependent people will relapse, Morgan said, and long-term cocaine use creates a myriad of problems. Cocaine negatively affects the cardiovascular system, puts users at a higher risk of contracting HIV/AIDS and impairs cognitive performance. Its secondary social effects can be devastating, he added.

Though there is still societal resistance to accepting addiction as a brain disease, Morgan said he thinks these views will shift as researchers develop better medications that effectively treat addiction. The National Institute on Drug Abuse now describes addiction as “a chronic relapsing disease caused by changes in the brain and characterized by uncontrollable drug-seeking no matter the consequences.” In a recent press release regarding the publication of a commentary, NIDA suggested that “the brain disease model of addiction is strongly supported by scientific evidence.”

Morgan said there will likely be future studies following their research, and that some may focus on the role of sleep in treating different kinds of addiction disorders. He noted that researchers are already finding that chronic use of other drugs leads to reductions in slow-wave sleep, similar to what is seen in cocaine dependence. It is possible that improving patients’ sleep could become a common path towards improving treatment outcomes.

According to the Drug Enforcement Administration, government agencies estimate that Americans spend roughly $65 billion on illegal drugs every year.