The neurobiological and neurocognitive consequences of chronic cigarette smoking in alcohol use disorders

A vast body of research attests to the adverse effects of chronic smoking on cardiac, pulmonary, and vascular function as well as the increased risk for various forms of cancer. However, comparatively little is known about the effects of chronic smoking on human brain function. Although smoking rates have decreased in the developed world, they remain high in individuals with alcohol use disorders. Despite the high prevalence of comorbid chronic smoking in alcohol use disorders, very few studies have addressed the potential neurobiological or neurocognitive effects of chronic smoking in alcohol use disorders. Here, we briefly review the existing literature on the neurobiological and neurocognitive consequences of chronic cigarette smoking and summarize our neuroimaging and neurocognitive studies on the effects of comorbid chronic excessive alcohol consumption and cigarette smoking in treatment-seeking and treatment-naïve populations. Our research suggests comorbid chronic cigarette smoking modulates magnetic resonance-detectable brain injury and neurocognition in alcohol use disorders and that neurobiological recovery in our abstinent alcoholics is adversely affected by chronic smoking. Consideration of the potential separate effects and interactions of chronic smoking and alcohol consumption may foster a better understanding of specific mechanisms and neurocognitive consequences of brain injury in alcoholism and of brain recovery during sustained abstinence from alcohol. The material presented also contributes to ongoing discussions about treatment strategies for comorbid alcoholism and cigarette smoking and will hopefully stimulate further research into the neurobiological and neurocognitive consequences of chronic smoking in alcoholism and other substance use disorders.