Quitting smoking may be good for mental health, according to a recent study HealthDay reported.

Researchers at Washington University School of Medicine in St. Louis found that people who struggle with mood problems or addiction could safely quit smoking to alleviate depression and anxiety, HealthDay reported.

"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 A. Cavazos-Rehg said in a statement. "The assumption is that psychiatric problems are more challenging to treat and that quitting smoking may interfere with treatment."

For the study, investigators analyzed data from 4,800 daily smokers in the United States. As part of the study, they answered questions about drinking, smoking and mental health in two interviews conducted three years apart.

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, HealthDay reported.

The second survey shows that only 29 percent of those who had quit smoking had mood disorders, compared with 42 percent of those who still smoked. Alcohol problems affected 18 percent of those who had quit smoking versus 28 percent who had continued smoking. And drug abuse problems affected only 5 percent of those who had quit smoking compared with 16 percent of those who had continued smoking.

"We don't know if their mental health improves first and then they are more motivated to quit smoking or if quitting smoking leads to an improvement in mental health," Cavazos-Rehg said. "But either way, our findings show a strong link between quitting and a better psychiatric outlook."

Researchers said that when treating mental health disorders, doctors tend to overlook their patient's smoking habit, assuming it is best to tackle depression, anxiety or substance abuse problems first.

"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."