An extended course of treatment that combines cognitive behavioral therapy with the smoking cessation drug varenicline (Chantix) significantly improved the ability of individuals with serious mental illness to maintain abstinence from tobacco, according to a Massachusetts General Hospital (MGH) study.

The study, which was the first randomized, controlled trial of maintenance pharmacotherapy for smoking cessation in such patients, found that after a standard 12-week course of treatment using the combined therapies, participants who continued to received varenicline along with cognitive behavioral therapy for an additional 40 weeks were three times more successful in maintaining abstinence from smoking than those who received cognitive behavioral therapy and a placebo drug.

Researchers noted that after the initial 12-week cessation phase, during which all participants received daily doses of varenicline and weekly group cognitive behavioral therapy sessions, 87 of the original 203 participants (42 percent) were considered to be abstinent.

Those individuals were randomized to either continued varenicline or a placebo during the 40-week relapse prevention phase. Both groups continued to receive cognitive behavioral therapy on a schedule of declining frequency during the prevention phase, at the end of which all smoking cessation therapies were discontinued.

At the end of the yearlong research period, 60 percent of participants who received varenicline during the relapse prevention phase were abstinent, based on both self-reporting and on measured levels of exhaled carbon monoxide. By comparison, only 19 percent of the placebo group were abstinent at this point. While half of those in the placebo group had relapsed within 35 days of discontinuing varenicline, it took almost a year for half of those in the varenicline group to relapse.

According to the study results, continued cognitive behavioral therapy was not enough to prevent relapse in the placebo group. However, those in the varenicline group who did relapse tended to do so after cognitive behavioral therapy was reduced to a monthly schedule.

“Our study showed that cognitive behavioral therapy alone is not enough to help smokers with serious mental illness maintain the abstinence they achieved with a program combining both therapies,” said Eden Evins, MD, MPH, director of the MGH Center for Addiction Medicine and lead author of the report.

“Since we don’t know yet how well varenicline would work without cognitive behavioral therapy, we would recommend that these patients be offered both therapies together to support smoking cessation and continued abstinence.”