Researchers pinpoint why depressed smokers have a harder time resisting relapses.
An international team of researchers have pinpointed why quitting smoking is particularly difficult for depressed people and are now testing a new smoking cessation treatment, combining medication and behavioural activation therapy targeted at this population.
The paper, an extensive review of current research, offers a much deeper understanding of why nicotine withdrawal symptoms for people with depression make it much more difficult to quit smoking.
Co-author of the paper, Professor Lee Hogarth of the University of Exeter's Psychology department, said: "People have thought for some time that depressed smokers have difficulty quitting because they experience a more pronounced withdrawal syndrome, but the evidence is scarce because depressed smokers are hard to recruit and consequently have not been as studied.
"But now we have gathered together convincing empirical support for this theory, which can be used to justify new treatment approaches."
Senior author, Professor Brian Hitsman of the Northwestern University Feinberg School of Medicine said: "We've used this theory of withdrawal in depressed smokers to develop the first targeted approach for smoking cessation in this underserved population."
Depressed smokers experience adverse withdrawal states that contribute to resumption of smoking, including low mood, difficulty engaging in rewarding activities and impaired thinking/memory, the paper reports. These symptoms are more severe for people with depression than for those without depression. In addition, depressed smokers tend to have fewer ways to cope with the symptoms and the nicotine in cigarettes helps to mitigate these problems, which is why depressed people tend to relapse at higher rates.
"Many smokers learn, 'If I smoke in this situation, my mood gets better.' But while smoking improves mood in the short term, it produces a long-term decline in mood," said lead author Amanda Mathew, research assistant professor in preventive medicine at Feinberg and a licensed clinical psychologist. "On the other hand, successfully quitting smoking is associated with improvements in mental health."
The review found that depressed smokers' first adverse state while trying to quit is a combination of "low positive affect" (low pleasure and engagement in rewarding activities, such as socializing or physical activity) and "high negative affect" (feelings of anger, sadness, guilt or anxiety). The second adverse state is "cognitive impairment" (difficulty making decisions, focusing and memory).
The study's researchers have begun testing a treatment that targets the specific challenges depressed smokers face when they're quitting. People who have clinical depression have typically been excluded from smoking cessation clinical trials.
The FDA-approved medication Chantix is coupled with a type of behavior therapy called "behavioral activation" to treat the depressed smokers. Researchers are investigating whether Chantix reverses thinking and memory problems that depressed smokers experience during withdrawal, and whether the behavioral activation improves smokers' moods so they engage in normal pleasurable activities, and thus have less desire to smoke and are able to resist relapsing.
Behavioral activation is an effective treatment for depression, but this is the first time it is being used as a treatment for smoking cessation among depressed smokers.
The clinical study is being conducted at Northwestern Memorial Hospital and the University of Pennsylvania and is currently accepting participants.
The study is funded by the National Cancer Institute grant number R01 CA184211 of the National Institutes of Health.
'Cigarette smoking and depression comorbidity: systematic review & proposed theoretical model' by A. Mathew, L. Hogarth, A. Leventhal, J. Cook, B. Hitsman in the international journal Addiction.