achieved smoking cessation (79 percent) were randomly assigned to relapse prevention skills training, group discussion, or no further treatment. Group discussion and no-further-treatment conditions were equivalent in effectiveness (34 percent and 33 percent abstinence after one year), while the skills-training group was significantly superior (41 percent). Further efforts are needed to determine maximally effective strategies to maintain behavior change.
Formal cessation programs commonly succeed in helping 15-25 percent of participants to quit (U.S. DHHS, 1996; Warner, 2000), a figure dramatically higher than all other tobacco control interventions. Nonetheless, it is the case that relatively few smokers participate in these programs, and the vast majority of smokers who quit do so without the aid of a formal program.
Like smoking cessation, there is a portfolio of interventions designed to change other risk behaviors, including diet, physical inactivity, and alcohol and substance use. Many of these interventions are important both to prevent illness in the healthy and to prevent recurrence or delay illness progression in those who are managing chronic illness, such as coronary heart disease. This brings us to the second category of behavioral interventions, involving coping with chronic illness. This is a particularly important area, given the growing segment of the population that lives with chronic illness. Psychological interventions have shown considerable promise in the management of cancer. These interventions have been shown to help individuals manage the side effects of chemotherapy, and there is also evidence that psychosocial interventions can increase disease-free intervals and length of survival for cancer patients (Compas et al., 1998). Moreover, short-term psychiatric group intervention was associated with long-term changes in the natural killer cell (NK) system in a group of patients with newly diagnosed melanoma and good prognoses (Fawzy et al., 1990). At six months, 100 percent of the intervention group showed increases in CD 16 NK cells, 74 percent showed increases in CD 56 NK cells, and 94 percent showed increases in Leu-7 large granular lymphocytes. These changes indicate a consistent increase in the number of NK cells, seemingly in response to the intervention, suggesting that the NK cells' system might be responsive to psychological or behavioral influences. It remains to be determined whether these perturbations in cell immunity have downstream health consequences.
Some evidence supports the effectiveness of social interventions for prolonging survival of cancer patients. One study assessing the effect of group therapy on patients with metastatic breast cancer, for example, found that those participating in weekly group therapy for a year not only experienced reduced anxiety, depression, and pain but survived significantly longer than did controls—by an average of nearly 18 months, measured at a 10year follow-up (Spiegel et al., 1989). However, other studies have not