(PhysOrg.com) -- Excessive drinking or smoking by a husband or wife can strain a marriage. However, is it substance use specifically that causes problems within a relationship, or is it the difference in the amount of drinking and smoking between a husband and wife that loosens the ties that bind?
That question is the crux of a report by Gregory G. Homish, Ph.D., assistant professor of health behavior, and colleagues in University at Buffalo's School of Public Health and Health Professions and UB's Research Institute on Addictions.
The answer, based on an ongoing nine-year longitudinal study of newly married couples, is not necessarily predictable. Results gathered from couples after seven years of marriage showed that when a couple's drinking habits were similar, both partners remained relatively satisfied with their marriage. The same results were found for smoking.
It is when one spouse drank heavily or smoked while the other did not -- the discrepancy between spouse's habits -- that dissatisfaction set in, the study found. Relationships deteriorated even more when one spouse, but not the other, indulged excessively in both.
"Most studies that investigate the impact of substance use focus solely on individual-level risk factors," said Homish, "and do not consider the impact of social network influences such as those that exist from a partner."
Results of the seven-year follow-up appear in a recent issue of the journal Addiction.
The study is following 634 couples who were recruited between 1996-99 when they applied for a marriage license. The majority of the men and women were European-American, while approximately one-third was African-American and a small percentage were Hispanic, Asian and Native American.
At the couples' first, second, fourth and seventh wedding anniversaries (waves 2, 3, 4 and 5) they were mailed questionnaires similar to the one they completed when they entered the study. At the fifth assessment (wave 6 assessment currently is being completed ) 79.7 percent of the wives and 68.1 percent of husbands completed the questionnaire.
Drinking history was assessed on a 0-9 point scale, from no drinking during the past year to drinking every day. The frequency of drinking six or more drinks on one occasion in the last year was assessed using the same nine-point scale. Heavy drinking was defined as the maximum of these two responses.
The discrepancy of drinking between husbands and wives was calculated by subtracting wife's past-year heavy drinking from husband's past-year heavy drinking.
For those who indicated they smoked, the amount of smoking was determined on an eight-point scale, from a few cigarettes per day or less, to two packs a day or more. Smoking discrepancy indicated whether couples were concordant -- if they both smoked or neither smoked -- or were discordant -- if only one person smoked.
Results from the earlier time points had shown initial declines in marital satisfaction followed by a leveling off after the first few years. At each assessment, the difference in heavy drinking between spouses was more common than the difference in smoking. About 15 percent of couples reported being discrepant in both smoking and drinking.
"There are important clinical implications related to these findings," Homish noted. "For example, if one partner of a heavy drinking couple enters treatment for his/her alcohol use, the break-up of the 'drinking partnership' could have unintended negative outcomes for the couple. "Therefore, approaches such as behavior couples therapy that assess and treat both partners could have a more beneficial outcome at both the individual and family level.
"In terms of research implications, the current findings suggest that an assessment of substance use should extend beyond quantity and frequency of substance use and also incorporate information about the partner's behavior."
Provided by University at Buffalo (news : web)
Explore further: Recombinant peptide for transplantation of pancreatic islets in mice models of diabetes