“We can't say that we've found a cause-and-effect relationship between smoking and decreased thinking ability, or neuro-cognitive proficiency,” says Glass. “But we hope our findings of an connection will lead to further examination of this important issue. Perhaps it will help give smokers 1 more reason to quit, and encourage quitting smoking among those who are also trying to control their drinking.”
 
Many alcoholism-recovery programs don't emphasize quitting smoking, even though smoking can be a social and possibly chemical “cue” associated with drinking alcohol.
Glass notes that her team's paper is being published, coincidentally, at the same time as a paper from a team at the University of California, San Francisco, in which brain scans showed that alcoholics who smoke have lower brain volume than alcoholics who don't smoke, and that cognitive function decreases with brain volume among non-smoking alcoholics, but not smoking alcoholics.

Taken together with previous epidemiological studies, the 2 new papers feed a growing body of evidence for a link between long-term smoking and thinking ability, says Robert Zucker, Ph.D., professor of Psychology in the University of Michigan Departments of Psychology and Psychiatry and, director of the UMARC. Zucker is senior author on the new paper led by Glass.