A new study is the first to look at the interactive effects of smoking status and age on neurocognition in treatment-seeking alcohol dependent (AD) individuals. Findings show that AD individuals who currently smoke show more problems with memory, ability to think quickly and efficiently, and problem-solving skills than those who don’t smoke, effects which seem to become worse with age.
From the press release:
“The independent and interactive effects of smoking and other drug use on cognitive functioning among individuals with AD are largely unknown,” added Alecia Dager, associate research scientist in the department of psychiatry at Yale University. “This is problematic because many heavy drinkers also smoke. Furthermore, in treatment programs for alcoholism, the issue of smoking may be largely ignored. This study provides evidence of greater cognitive difficulties in alcoholics who also smoke, which could offer important insights for treatment programs. First, individuals with AD who also smoke may have more difficulty remembering, integrating, and implementing treatment strategies. Second, there are clear benefits for thinking skills as a result of quitting both substances.”
Durazzo and his colleagues compared the neurocognitive functioning of four groups of participants, all between the ages of 26 and 71 years of age: never-smoking healthy individuals or “controls” (n=39); and one-month abstinent, treatment-seeking AD individuals, who were never-smokers (n = 30), former-smokers (n = 21) and active-smokers (n = 68). Evaluated cognitive abilities included cognitive efficiency, executive functions, fine motor skills, general intelligence, learning and memory, processing speed, visuospatial functions, and working memory.
“We found that, at one month of abstinence, actively smoking AD [individuals] had greater-than-normal age effects on measures of learning, memory, processing speed, reasoning and problem-solving, and fine motor skills,” said Durazzo. “AD never-smokers and former-smokers showed equivalent changes on all measures with increasing age as the never-smoking controls. These results indicate the combination of alcohol dependence and active chronic smoking was related to an abnormal decline in multiple cognitive functions with increasing age.”
“These results indicate the combined effects of these drugs are especially harmful and become even more apparent in older age,” said Dager. “In general, people show cognitive decline in older age. However, it seems that years of combined alcohol and cigarette use exacerbate this process, contributing to an even greater decline in thinking skills in later years.”
Durazzo agreed. “Chronic cigarette smoking, excessive alcohol consumption, and increasing age are all associated with increased oxidative damage to brain tissue,” he said. “Oxidative damage results from increased levels of free radicals and other compounds that directly injure neurons and other cells that make up the brain. Cigarette smoking and excessive alcohol consumption expose the brain to a tremendous amount of free radicals. We hypothesize that chronic, long-term exposure to cigarette smoke and excessive alcohol consumption interacts with the normal aging process to produce greater neurocognitive decline in the active-smoking AD group.”
Abstract of the research:
Background: Increasing age and chronic cigarette smoking are independently associated with adverse effects on multiple aspects of neurocognition in those seeking treatment for alcohol use disorders. However, the potential interactive effects of age and cigarette smoking on neurocognition in early abstinent alcohol-dependent individuals (ALC) have not investigated.
Methods: Cross-sectional performances of never-smoking healthy comparison participants (nvsCOM; n = 39) and 1-month-abstinent, treatment-seeking, never-smoking (nvsALC; n = 30), former-smoking (fsALC; n = 21), and actively smoking (asALC; n = 68) ALC were compared on a comprehensive neurocognitive battery. Domains of functioning evaluated were cognitive efficiency, executive functions, fine motor skills, general intelligence, learning and memory, processing speed, visuospatial functions and working memory. Participants were between 26 and 71 years of age at the time of assessment.
Results: asALC showed steeper age-related effects than nvsCOM on the domains of visuospatial learning, auditory-verbal memory, cognitive efficiency, executive functions, processing speed, and fine motor skills. In pairwise comparisons, fsALC and asALC performed more poorly than both nvsCOM and nvsALC on multiple domains; nvsCOM and nvsALC showed no significant differences. Domain scores for the ALC groups generally fell in the low-to-high-average range of functioning. A clinically significant level of impairment was apparent in only 25% of ALC participants on visuospatial learning, visuospatial memory, and fine motor skills domains. Measures of alcohol use or consumption were not significantly related to neurocognition in the ALC cohorts.
Conclusions: The age-related findings suggest that the combination of active chronic smoking and alcohol dependence in this 1-month-abstinent ALC cohort was associated with greater than normal age-related effects in multiple domains. In general, a low level of clinically significant impairment was observed in the alcohol-dependent participants. The findings from this study, in conjunction with previous research, strongly support smoking cessation interventions for those seeking treatment for alcohol and substance use disorders.
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