Here's a New Reason for Quitting Smoking

Contrary to popular opinion, quitting reduces depression, scientists find.

ByABC News
December 7, 2010, 4:16 PM

Dec. 8, 2010 — -- Cigarette smokers frequently argue that the reason they don't stop smoking is that quitting would make life more depressing. But new research indicates the opposite is true. Persons who quit in a clinical trial actually showed lower signs of depression for weeks and months after giving up the weed.

Smokers who quit were happiest during periods of abstention, and if they began smoking again their moods turned darker, according to psychologist Christopher Kahler of Brown University, lead author of a study in the journal Nicotine & Tobacco Research. Participants in the study who never quit smoking were the most depressed of all. Those who quit entirely were the least depressed at the beginning of the months-long study and they remained the happiest throughout the project.

"We're still puzzling about why that's the case," Kahler said in a telephone interview. "A sense of personal triumph makes a lot of sense. The people in this study were really motivated to succeed. And when you succeed at something that's important to you, you naturally feel better."

But he concedes that many ex-smokers complain that "they felt miserable for weeks" after quitting, and many say they resumed smoking because they felt depressed or anxious or irritated about something in their lives. Yet in this study, the less people smoked, the less they suffered from depression.

The study probes an area that has not been widely studied and the question of whether smoking increases or decreases depression is still a bit up in the air. It's not clear yet whether these findings would apply to everybody, because all the participants were classified as "heavy social drinkers" of alcohol, and 90.7 percent were non-Hispanic whites.

In fact, this wasn't even the initial goal of the study, which was funded by the National Institute of Drug Abuse. Kahler and his colleagues at Brown and the University of Southern California set out to determine if abstaining from alcohol could help people quit smoking.

So they ended up with 236 men and women who volunteered for the study. All of the participants were "heavy drinkers," meaning the men had at least 14 drinks per week and the women had at least seven drinks per week.