How smoking and depression are related is not clear, but experts have a few theories. "Nicotine improves your response to reward—it makes the blue sky bluer," says A. Eden Evins, MD, associate professor of psychiatry at Harvard Medical School and director of the Center for Addiction Medicine at Massachusetts General Hospital in Boston. "It binds to receptors in the brain and causes the release of glutamate and dopamine, chemicals that are associated with pleasure." As Sarah Levenson, 38, an executive assistant in Boston, who was diagnosed with depression in her 20s, puts it, "Cigarettes do this crazy thing: They stimulate me when I'm not stimulated but also calm me down when I'm overly anxious."
For people like Levenson, quitting can be particularly hard. Withdrawal symptoms, including anxiety and other mood changes, may be more severe when you're battling depression, says Nancy Rigotti, MD, professor of medicine at Harvard Medical School and director of the Tobacco Research and Treatment Center at Massachusetts General Hospital. And the newest smoking-cessation drug, Chantix (which blocks nicotine receptors in your brain), can actually aggravate depressive symptoms. Fortunately, there is a range of other aids that can help. Zyban, for example, is an antidepressant (also marketed as Wellbutrin) that increases dopamine and norepinephrine. However, the best plan, Rigotti says, "is to get into a behavioral treatment program that provides support and follow-up."
That is what Levenson did: After finding a combination of therapy and medication (Celexa) that stabilized her mood, she joined a support group at Mass General. Within two weeks, she was able to quit, using nicotine patches. "I'm absolutely sure it's harder for someone with depression to stop," she says. "But once you do, you're surprised at how much better you feel."