Stages of physical dependence in New Zealand smokers: Prevalence and correlates

• Physical tobacco dependence develops through stages of wanting, craving and needing.
• Stages of physical dependence correlate with changes in brain addiction pathways.
• We describe the distribution of smokers across the stages of physical dependence.
• Multiple neural mechanisms may be involved in the progression of physical dependence.

BackgroundPhysically dependent smokers experience symptoms of wanting, craving or needing to smoke when too much time has passed since the last cigarette. There is interest in whether wanting, craving and needing represent variations in the intensity of a single physiological parameter or whether multiple physiological processes may be involved in the developmental progression of physical dependence.AimOur aim was to determine how a population of cigarette smokers is distributed across the wanting, craving and needing stages of physical dependence.MethodsA nationwide survey of 2594 New Zealanders aged 15 years and over was conducted in 2014. The stage of physical dependence was assessed using the Levels of Physical Dependence measure. Ordinal logistic regression analysis was used to assess relations between physical dependence and other variables.ResultsAmong 590 current smokers (weighted 16.2% of the sample), 22.3% had no physical dependence, 23.5% were in the Wanting stage, 14.4% in the Craving stage, and 39.8% in the Needing stage. The stage of physical dependence was predicted by daily cigarette consumption, and the time to first cigarette, but not by age, gender, ethnicity or socioeconomic status.ConclusionFewer individuals were in the craving stage than either the wanting or needing stages. The resulting inverted U-shaped curve with concentrations at either extreme is difficult to explain as a variation of a single biological parameter. The data support an interpretation that progression through the stages of wanting, craving and needing may involve more than one physiological process.What this research addsPhysical dependence to tobacco develops through a characteristic sequence of wanting, craving and needing which correspond to changes in addiction pathways in the brain. It is important to neuroscience research to determine if the development of physical dependence involves changes in a single brain process, or multiple processes. Our data suggests that more than one physiologic process is involved in the progression of physical dependence.