WEDNESDAY, Feb. 12, 2014 (HealthDay News) -- Quitting smoking may be as good for your mental health as it is for your physical health, a new study suggests.

Researchers analyzed data from 4,800 daily smokers in the United States who took part in two surveys conducted three years apart. Those who had an addiction or other mental health problems in the first survey were less likely to have those issues in the second survey if they'd quit smoking, the investigators said.

The first survey found that 40 percent of the participants had mood or anxiety disorders or a history of these conditions, 50 percent had alcohol problems and 24 percent had drug problems.

The second survey showed that 29 percent of those who'd quit smoking had mood disorders, compared with 42 percent of those who still smoked. Alcohol problems were reported by 18 percent of quitters and 28 percent of ongoing smokers, and drug problems affected 5 percent of quitters and 16 percent of those who still smoked.

The study findings were released online Feb. 11 in the journal Psychological Medicine.

When treating those with mental health disorders, doctors may overlook their patients' smoking habit in the belief that it's best to deal with the psychiatric issues first, the researchers at the Washington University School of Medicine in St. Louis noted in a university news release.

"Clinicians tend to treat the depression, alcohol dependence or drug problem first and allow patients to 'self-medicate' with cigarettes if necessary," lead investigator Patricia Cavazos-Rehg, an assistant professor of psychiatry, said in the news release. "The assumption is that psychiatric problems are more challenging to treat and that quitting smoking may interfere with treatment."

However, these findings suggest a strong link between quitting smoking and improved mental health. But while the researchers found an association between the two, the study did not prove a cause-and-effect relationship.

"We really need to spread the word and encourage doctors and patients to tackle these problems," Cavazos-Rehg said. "When a patient is ready to focus on other mental health issues, it may be an ideal time to address smoking cessation, too."