'Casual' smokers have a greater risk of hazardous drinking and alcohol-use disorders

September 23, 2008

Non-daily or "casual" smokers tend to slip through the cracks of prevention efforts. Yet casual smoking and heavy drinking are prevalent behaviors among young adults and, furthermore, casual smoking occurs primarily in the context of alcohol use. A new study of casual smoking and drinking behavior has found that non-daily smoking confers an increased risk of hazardous drinking and alcohol-use disorders (AUDs).

Results will be published in the December issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"Our goal in this study was to look at a range of smoking behaviors – daily smoking, nondaily smoking, nonsmoking – and associations with binge drinking, hazardous drinking, and AUDs," said Sherry A. McKee, associate professor of psychiatry at Yale University School of Medicine. "The National Epidemiological Survey on Alcohol and Related Conditions (NESARC) provided us with a unique opportunity to investigate these relationships in young adults aged 18 to 25 years. We were able to examine whether associations between non-daily smoking and alcohol use were specific to just college students, or generalized to young adults who were not college students."

"Non-daily smokers are a fast-growing subpopulation of smokers, now constituting at least 25 percent of all adult smokers in the US," added Saul Shiffman, a professor in the departments of psychology and pharmaceutical science at the University of Pittsburgh. "Furthermore, this study is important because it sheds light on particular groups defined by age and patterns of smoking and drinking. This can advance our understanding of the range of drinking patterns, and also the developmental trajectory of problem drinking."

Using NESARC data, researchers queried 5,838 young adults on their current smoking behavior (during the preceding 12 months) as well as weekly consumption of alcohol, frequency of alcohol use, frequency of binge-drinking behavior, rates of hazardous drinking, and rates of DSM-IV alcohol diagnoses as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition.

Compared to non-smokers, casual smokers were 16 times more likely to be hazardous drinkers, and five times more likely to meet criteria for an AUD.

"We anticipated that the associations between alcohol use and smoking would be greatest in non-daily smokers, but were surprised by the degree of the associations," said McKee. "While casual smoking was more common in college students, the relationships between smoking and drinking behavior were the same for young adults whether they were students or not."

"Even though non-daily smokers were less likely than daily smokers to drink daily, they were more likely to exceed weekly and daily quantities defined by the NIAAA as hazardous," added Shiffman. "So, even though daily smokers drank more, non-daily smokers drank more hazardously. This, in conjunction with other research,] suggests that these casual smokers neither smoke nor drink regularly, but rather may have periodic binges where they may do both, perhaps as they become disinhibited at parties. Drinking and smoking may also mutually promote each other, leading to bouts of heavy drinking and smoking."

"Currently, the majority of states have enacted smoke-free bans that extend to smoking in venues where alcohol is served," said McKee. "Research indicates that smoking bans can reduce alcohol consumption in bars, particularly among heavy drinkers."

Shiffman agrees. "Where bans have been imposed on smoking in bars – notably in Ireland – they have been met with stiff resistance, but ultimately succeeded, encouraging smokers to quit, and creating more inviting environments for non-smokers in pubs," he said. "By interfering with the link between smoking and drinking, such policies may also disrupt developmental trajectories towards problem drinking and heavy smoking, and thereby yield a long-term public health benefits as well."

Shiffman added that, ironically, alcoholics are more likely to die of smoking-related diseases than from the consequences of drinking.

"Although the relationship between drinking and smoking has long been documented and, as this paper illustrates, is very strong, it has received too little research attention," he said. "Perhaps smoking status can be used as an initial screen for alcohol problems. Perhaps these behaviors should be considered together, breaking through the silos that separate these areas of research. The strong linkages suggest that understanding the association could teach us much about both behaviors, and their underlying genetic, pharmacological, behavioral, and social determinants."

Source: Alcoholism: Clinical & Experimental Research