"We have found that stress affects men and women differently when it comes to nicotine addiction and relapse," says lead researcher Mustafa al'Absi, Ph.D., of the University's Behavioral Medicine Laboratories in the School of Medicine, Duluth and Cancer Center member. "During abstinence women have more difficulties with the emotional side effects, while men have difficulties with the biological changes they experience. In future studies, we hope to discover the mechanisms responsible for these gender differences, so that we can develop more effective intervention strategies to help men and women overcome this addiction."
Previous research has found that during periods of acute psychological stress, several physiological and biological changes occur in the body. Research by al'Absi on smoking focuses on the hypothalamic-pituitary-adrenocortical axis (HPA). One of the hormones released by this system is cortisol, an important biological indicator of stress. Cortisol interacts with several brain pathways that are affected by nicotine and may be the reason why stress leads to smoking or to craving for cigarettes.
Through earlier studies, al'Absi's team discovered that stress, seen through changes in cortisol and other HPA hormones, intensifies withdrawal symptoms. "We now wanted to know whether stressful events make it difficult for smokers to quit and increase their risk for relapse. And if stress contributes to smoking and relapse, which biological and psychological mechanisms are involved?"
This study examined 72 smokers (38 men and 34 women), all of whom had a long smoking history but were otherwise healthy. Their levels of cortisol were assessed at the participants' usual smoking rate and again during the first 24 hours of their abstinence. Their stress responses were also measured after the first day of abstinence when several hormonal, physiological, and psychological measures were obtained before and after performing a public-speaking test and a mental-performance challenge. Finally, participants came to the lab four times over four weeks for follow-up interviews.
Results showed that approximately 48 percent of smokers relapsed within the first week of quitting--comparable to large population studies. Participants who relapsed reported greater distress and withdrawal symptoms during the initial 24 hours of abstinence. They also exhibited a steeper decline of cortisol concentrations after abstinence compared with a previous day when they were smoking at their usual rate.
Cortisol responses to stress were greater in men than in women. However, the acute stressful challenges increased craving and intensity of withdrawal symptoms, especially in women. They also found that women who experience intense withdrawal symptoms tended to relapse sooner than women who experience less intense symptoms. Withdrawal symptoms did not relate to relapse-risk in men, however. Men who exhibited lower hormonal responses to stress relapsed sooner than men who showed higher responses. Hormonal responses did not relate to relapse-risk in women.
This study was supported by grants from the National Institutes of Health / National Cancer Institute.