The study involved 25 women and 35 men, aged 18 to 42, who kept a diary over several days recording their mood and smoking behaviour. The urge to smoke was more strongly associated with anger, anxiety and alertness in men than in women. Feelings of sadness or fatigue were linked with the urge to smoke in men only. When the men smoked they felt less angry and it reduced their feelings of sadness. In women smoking was associated with feelings of happiness which were not reported by the men.