“Our results are inconsistent with the notion that abstaining from smoking after a planned quit attempt exacerbates depressive symptoms. Instead, it was only participants who never abstained whose depressive symptoms appeared consistently higher after the quit date compared with before,” researchers report.
The study, from Christopher W. Kahler, PhD, of the Center for Alcohol and Addiction Studies, Brown University, Providence, Rhode Island, and colleagues, was published online November 24 in the journal Nicotine & Tobacco Research.
Knowing whether smoking cessation is associated with reduction or exacerbation of depressive symptoms is important for 2 reasons, the researchers say. “If quitting smoking leads to worse psychological functioning even after withdrawal symptoms have ebbed, that must be addressed in treatment,” they write.
Conversely, if those who successfully kick the habit feel better than those who return to smoking, “that information could be used to encourage smokers to make and sustain quit attempts,” they add.
To investigate, Dr. Kahler’s group studied 236 heavy smokers of at least half a pack per day who were enrolled in a randomized clinical trial testing the efficacy of incorporating a brief alcohol intervention into smoking cessation. The subjects, who were not clinically depressed, received nicotine patches and behavioral counseling and then agreed on a quit date.
The researchers measured depressive symptoms 1 week before the quit date and 2, 8, 16, and 26 weeks after that date using the Center for Epidemiologic Studies–Depression (CES-D) scale. They created multilevel models to quantify the difference in depressive symptoms associated with being abstinent vs smoking at each assessment.
All but 29 subjects exhibited 1 of 4 different quitting behaviors: 99 subjects never abstained, 44 were only abstinent at the 2-week assessment, 33 remained abstinent at the 2- and 8-week assessment, and 33 managed to stay cigarette free for the entire assessment period.
“To our knowledge, this is the first examination of within-person covariation between smoking abstinence and depressive symptoms following a cessation attempt,” the investigators note in their report.
Mood Varies Based on Success
On average, they found that depressive symptoms increased slightly after a quit attempt; however, there was significant variability in depressive symptoms based on abstinence patterns.
Across the different quitting behaviors, abstinence at any given checkup, compared with continued smoking, was associated with a significant reduction of 2.74 points (P < .0001) on the CES-D. Those who were abstinent at all assessments had the lowest levels of depressive symptoms, the researchers found. Smokers who transitioned from smoking to abstinence and back to smoking showed the lowest levels of depressive symptoms when abstinent; their mood darkened after going back to smoking. Those who were never abstinent showed gradual increases in depressive symptoms over time. "People who are going back and forth and continue to smoke a little tend to struggle with not feeling great because they aren't getting as much nicotine as they are use to and they also are not having the full psychological benefits of being successful," Dr. Kahler told Medscape Medical News. From the current study, he said, it also seems like the people who continue to try to quit are worse off than those who give up and go back to smoking. He emphasized that the people in the current study were not depressed initially and their level of depressive symptoms was "very, very low" throughout the study. Overall, these findings do not support the view that abstinence from smoking contributes to depressive symptoms. "That's not to discount the fact that when people quit, they tend to feel irritable and restless and certainly have some symptoms of nicotine withdrawal," Dr. Kahler said. "But when we measure, overall, within a pretty short amount of time of having successfully quit, people do seem to report less of those symptoms of depression than they had before." Reached for outside comment, John Hughes, MD, of the Department of Psychiatry at the University of Vermont in Burlington, who was not involved in the study, said a key limitation of the research is that the first measurement of depressive symptoms was not taken until 2 weeks after quitting. "Other studies have shown increased depression in the first week or 2 of quitting, and this would have been missed by this study," Dr. Hughes told Medscape Medical News. "There certainly is a bit of a rise in negative mood in that first week," Dr. Kahler said. But he also said a study he conducted in 2002 showed that "most of that recovers by the end of the second week for people who are successful."