Women have a harder time quitting smoking than men, and their menstrual cycle may be one of the reasons why, new research suggests.

According to study published in Psychiatry Journal, women crave cigarettes more strongly during their periods. The study found that the urge to smoke is stronger at the beginning of the phase that begins after menstruation.

The study was led by neuroscientist Adrianna Mendrek of the University of Montreal and its affiliated Institut universitaire en santé mentale de Montréal.

Based on her findings, Mendrek said it could be easier for women to overcome withdrawal symptoms after ovulation, when their estrogen and progesterone levels are elevated. 

“Taking the menstrual cycle into consideration could help women to stop smoking,” Mendrek said.

Mendrek's study did not consider psycho-social factors, as the women involved were only asked about the phase they were at in their menstrual cycle. 

“Stress, anxiety and depression are probably the more important factors to take into consideration,” Mendrek said.

During the study, researchers worked with 34 men and women who each smoke more than 15 cigarettes a day. All participants filled out questionnaires and underwent MRI brain scans. The women underwent the scans twice -- at the beginning and end of their menstrual cycle -- and had their estrogen and progesterone levels tested. 

Science shows that fewer than one in 10 ex-smokers manages to stay smoke-free a year after quitting, and women have a harder time breaking the habit than men. In fact, in studies involving rodents addicted to nicotine and other substances, scientists have observed differences in sexes. 

"Female rats become addicted more quickly, and are willing to work harder for the same quantity of dose,” Mendrek said.

While these conclusions are more complicated when it comes to humans, Mendrek and her team believe that females are perhaps at higher risk of addiction -- and sex hormones may be to blame. 

As they come to their conclusion, tobacco use by women is increasing. Mendrek says she hopes her study will encourage researchers to pay more attention to biology in their work. 

“A greater knowledge of the neurobiological mechanisms governing addiction should enable us to better target treatment according to the smokers profile,” she said.