Women quitting smoking should consider effect of their period

Women quitting smoking should consider effect of their period

Women who smoke have a harder time quitting than men, even when they smoke the same amount, so researchers from the University of Montreal set out to assess whether sex hormones had an influence on nicotine cravings.

Thirty four men and women who smoked more than 15 cigarettes a day underwent MRI brain scans while they looked at neutral pictures or pictures designed to make them want to smoke. They also filled out questionnaires. The women were scanned twice - once at the beginning of the follicular phase of their menstrual cycle and then again at the mid-luteal phase. Oestrogen and progesterone levels were also measured.

No significant differences were found between the men and women in terms of their neuronal circuits. However, the activation patterns for the women varied considerably over their menstrual cycle. Certain areas of their frontal, temporal and parietal cortex revealed greater activation during the follicular phase, while limited activation was recorded in the hippocamp during the luteal phase.

Adrianna Mendrek of the University of Montreal said: "Our data reveal that incontrollable urges to smoke are stronger at the beginning of the follicular phase that begins after menstruation. Hormonal decreases of oestrogen and progesterone possibly deepen the withdrawal syndrome and increase activity of neural circuits associated with craving."

She added: "Taking the menstrual cycle into consideration could help women to stop smoking." She believes that it could therefore be easier for women to overcome abstinence-related withdrawal symptoms during the mid-luteal phrase, i.e. after ovulation, when their levels of oestrogen and progesterone are elevated.

In drug studies involving rodents (nicotine and other substances), scientists have observed sex differences. "Female rats become addicted more quickly, and are willing to work harder for the same quantity of dose," Mendrek explained. This observation led Mendrek's team to conclude that females are perhaps at higher risk of addiction, and sex hormones could be the reason why.

However, she added, the  situation is much more complex in humans because each smoker is unique in terms of his or her tobacco use, personal history, personality, social situation and environment. "Stress, anxiety and depression are probably the more important factors to take into consideration," Mendrek said.

* Adrianna Mendrek, et al. Sex Differences and Menstrual Cycle Phase-Dependent Modulation of Craving for Cigarette: An fMRI Pilot Study. Psychiatry Journal. Volume 2014 (2014), Article ID 723632, 7 pages. doi: 10.1155/2014/723632

By Ingrid Torjesy, 

OnMedica, Monday 5 Jannuary 2015

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