Prior craving studies have reported the individual relationship of alcohol craving with gender, family history, social support, intensity of alcohol dependence, nicotine dependence as well as stress or mood state. In this cross-sectional study of actively drinking alcohol dependent subjects, we evaluated several novel covariates and re-evaluated some previously investigated covariates of craving. Unique covariates of alcohol craving found in this study included the following: race, subjective social support, problematic consequences of alcohol use, motivation for change, and sleep complaints. Alcohol craving was negatively associated with age. Craving was also positively associated with alcohol use, and mood disturbance. In a multivariate analysis, 34 % of the variance of alcohol craving was predicted positively by heavy drinking, mood disturbance and motivation for change; alcohol craving was negatively predicted by age.
These results support the individual association of most of the variables with craving, as we had hypothesized, with the exception of gender, family history of alcohol dependence and nicotine dependence. The lack of an association of gender and family history of alcohol dependence with craving may be due to sample characteristics; specifically, the relatively low number of female subjects, and most of our subjects lacking a family history of alcohol dependence in the first degree relatives. Similarly, the low level of nicotine dependence may have accounted for the lack of association of nicotine dependence with alcohol craving.
Age was inversely associated with craving in our subjects. This finding may help account for the better prognosis for older adults in alcoholism treatment.47
The increased craving in our Caucasian subjects may be associated with the racial differences in the efficacy of the drug, naltrexone, a mu-opioid receptor antagonist medication that decreases craving. The greater efficacy of naltrexone in Caucasian than African-American subjects has been related to the underlying higher prevalence of the genetic polymorphism of the Asp40 allele of the mu-opioid receptor 1 gene in Caucasians.10
In our study, social support was independently associated with craving. This finding may be possibly due to our actively drinking alcohol dependent subjects being in the company of others, who are also actively involved with drinking. Social supports was however, neither a predictor in the final model, nor seen to moderate the relationship of mood and craving in our subjects, as reported in previous studies.30,48
The proportion of heavy drinking days prior to entering treatment, a sign of severity of alcohol dependence, was significantly and positively associated with craving, as previously reported.1,12
Alcohol craving was associated with the problematic consequences of alcohol use, through its relationships with mood disturbance, heavy drinking, and motivation for change. Thus the increased craving secondary to psychosocial consequences after prolonged drinking may compel the alcohol dependent patients to seek treatment.
Motivation for change was positively associated with craving, another unique finding in this study. Motivation for change has previously been associated with decreased drinking at entry into the study,49
and with decreased post-treatment drinking after one year.50
Once drinking resumes, however, factors other than stages of change appear to be associated with the drinking.51
Using the construct of self efficacy,52
we may speculate that high craving state is associated with distress in these participants. This high craving may thus be associated with an increased motivation to seek change or treatment.
The subjects also reported symptoms of mood disturbance, that was individually associated with craving as has been shown before.17,53,54
Consistent with prior literature, our actively drinking subjects reported sleep complaints in the domain of insomnia.55
The individual relationship of sleep problems with craving, is another novel finding in this study. The variance of sleep abnormalities, however, was explained by the underlying mood disturbance, consistent with previous literature.56
Intensified sleep problems and REM sleep abnormalities have been reported in subjects with secondary depressive disorder.28,57
Treatment of insomnia in recovering alcoholics may therefore be considered a therapeutic target for the treatment of the mood symptoms and craving, and thus the underlying alcohol dependence.
The relationship between craving and these multiple variables in the final model may have an underlying neuro-anatomic basis. Alcohol craving have been associated with brain activity in the nucleus accumbens, anterior cingulate cortex, orbitofrontal cortex, and the limbic system.58,59
Neuro-anatomical correlates of sleep disturbance in depressed subjects have included cingulate cortex, insula, limbic system and basal ganglia.60
Reasoning and informed decisions have been associated with the prefrontal and cingulate cortex61
and the posterior cingulate and the hippocampus62
respectively. In summary, the areas of prefrontal cortex, orbitofrontal cortex, limbic system and basal ganglia may be crucial to the understanding of the underlying interrelationship of motivation and mood disturbance, and craving in alcoholics.
The limitations of this study were threefold. First, this was a convenience sample of treatment-seeking subjects and may not be representative of all alcohol dependent subjects. Second, the study was cross-sectional in nature; therefore the temporal relationship of alcohol craving with the other variables could not be elicited. Third, this study lacked the broad inclusion of certain minority populations (including Asians and Native Americans). Longitudinal studies will be necessary to clarify the relationships between craving and motivation for change, and, the interplay of different variables including social support and sleep problems with mood disorders and craving. These relationships may have important implications for integrated treatment planning in alcohol dependence.