It's hard to stay sober when you're depressed, says a new study on problem drinkers.
The study, led by Molly Kodl, a researcher at the Minneapolis VA Medical Centre, followed 462 people who tried to simultaneously give up alcohol and cigarettes.
At the starting of the study, the participants smoked at least five cigarettes a day and were alcohol dependent.
Among the group, typical problematic drinking symptoms included repeatedly imbibing more than planned, difficulty quitting or cutting down, and continuing to drink even though drinking caused problems such as hangovers or sleeping difficulty.
All volunteers were given intensive alcohol and smoking cessation treatment.
Up to a year and a half later, researchers surveyed the participants and asked about their alcohol and tobacco habits.
"Among those who were depressed, the odds of drinking, the next time you checked in with them six months later, were 1.5 times greater than the odds of drinking for individuals without significant depressive symptoms," Kodl said.
Of the people who were depressed, the majority suffered only mild to moderate mood problems.
"With significant depression, people report mood that is down in the dumps, loss of interest in things they used to enjoy, low energy, appetite changes and difficulty concentrating," Kodl said.
While depression seems to lessen the chances of alcohol abstinence, the study did not find a similar association for tobacco dependence.
"Depression did not significantly impact the odds of succeeding in quitting smoking in this study," Kodl said.
"Our study suggests that treating depression may help people recover from alcohol use problems, although more research is needed on this topic," she added.
The study is published in the journal Alcoholism: Clinical and Experimental Research.