The effects of chronic nicotine and alcohol use on neurocognitive function

Alcohol consumption behaviors and neurocognitive dysfunction and emotional distress in adult survivors of childhood cancer: a report from the Childhood Cancer Survivor Study

AIMS

To estimate the level of alcohol consumption behaviors in adult survivors of childhood cancer and to test associations between alcohol consumption behaviors and symptoms of neurocognitive impairment and emotional distress.

DESIGN

Retrospective cohort study with longitudinal follow-up of self-reported health outcomes.

SETTING

Childhood Cancer Survivor Study (CCSS), a 26-center study of ≥ 5-year survivors of childhood cancer diagnosed ≤ 21 years of age between 1970 and 1986 in the United States and Canada.

PARTICIPANTS

A total of 4484 adult survivors of childhood cancer [mean (standard deviation) age at evaluation = 34.8 (6.1) years; time from diagnosis = 24.8 (4.4) years] and 1651 sibling controls who completed surveys reporting on alcohol use, neurocognitive impairment and emotional distress.

MEASUREMENTS

Survivor report of alcohol use included age at drinking initiation and quantity and frequency of alcohol consumption. Neurocognition was assessed using the CCSS Neurocognitive Questionnaire. Emotional distress symptoms were measured using the Brief Symptoms Inventory-18 and the Posttraumatic Stress Diagnostic Scale.

FINDINGS

After adjustment for childhood cancer treatment exposures, including cranial radiation therapy, drinking initiation prior to 18 years of age was associated with 30% increased risk of subsequent memory problems [risk ratio (RR) = 1.3; 95% confidence interval (CI) = 1.1-1.5]. Younger age at drinking initiation was associated with future risk of depression (RR = 1.3; 95% CI = 1.1-1.5), anxiety (RR = 1.6; 95% CI = 1.3-2.1), and somatization (RR = 1.2; 95% CI = 1.1-1.4). Persistent heavy/risky drinking was associated with 80% increased risk of persistent psychological distress (RR = 1.8, 95% CI = 1.4-2.3).

CONCLUSIONS

Drinking initiation during adolescence is associated with modest increased risk for memory impairment and emotional distress in adult survivors of childhood cancer.

Early onset tobacco cigarette smokers exhibit deficits in response inhibition and sustained attention

BACKGROUND

Initiation of cigarette smoking during adolescence coincides with structural and cognitive neuromaturation. Thus, early onset smokers (EOS; initiated <16 years old) may be at unique risk of altered development of executive function relative to late onset smokers (LOS; initiated >16 years old). This study quantified the effects of age of smoking onset on response impulsivity and inhibitory control using a novel smoking Go/NoGo task (Luijten et al., 2011).

METHODS

Nicotine deprived adult EOS (n = 10) and LOS (n = 10) and adult healthy non-smokers (HNS; n = 10) were shown smoking-related and neutral images with either a blue (Go) or yellow (NoGo) frame. Participants were instructed to respond to blue-framed Go trials quickly and accurately, and withhold responding for yellow-framed NoGo trials.

RESULTS

EOS made more Go response accuracy errors (p ≤ 0.02) and failed more frequently to inhibit responses to NoGo trials (p < 0.02) than LOS and HNS. EOS also made more errors in inhibiting responses to smoking-related (p ≤ 0.02) and neutral (p ≤ 0.02) NoGo trials. EOS reported greater baseline craving for cigarette smoking than LOS (p < 0.04), and craving was significantly associated with greater omission errors (p ≤ 0.04).

CONCLUSIONS

EOS exhibited greater difficulty than LOS in responding accurately to Go stimuli and withholding responses to both smoking and neutral NoGo stimuli, indicating greater response impulsivity, poor attention, and deficits in response inhibition. These findings suggest that EO smoking, in particular, contributes to diminished task-related attention and inhibitory control behaviors in adulthood and provide support for the tobacco-induced neurotoxicity of adolescent cognitive development (TINACD) theory (DeBry and Tiffany, 2008).

Current Heavy Alcohol Consumption is Associated with Greater Cognitive Impairment in Older Adults

BACKGROUND

The acute consumption of excessive quantities of alcohol causes well-recognized neurophysiological and cognitive alterations. As people reach advanced age, they are more prone to cognitive decline. To date, the interaction of current heavy alcohol (ethanol [EtOH]) consumption and aging remains unclear. This study tested the hypothesis that negative consequences of current heavy alcohol consumption on neurocognitive function are worse with advanced age. Further, we evaluated the relations between lifetime history of alcohol dependence and neurocognitive function METHODS: Sixty-six participants underwent a comprehensive neurocognitive battery. Current heavy EtOH drinkers were classified using National Institute on Alcohol Abuse and Alcoholism criteria (EtOH heavy, n = 21) based on the Timeline follow-back and a structured clinical interview and compared to nondrinkers, and moderate drinkers (EtOH low, n = 45). Of the total population, 53.3% had a lifetime history of alcohol dependence. Neurocognitive data were grouped and analyzed relative to global and domain scores assessing: global cognitive function, attention/executive function, learning, memory, motor function, verbal function, and speed of processing.

RESULTS

Heavy current EtOH consumption in older adults was associated with poorer global cognitive function, learning, memory, and motor function (ps < 0.05). Furthermore, lifetime history of alcohol dependence was associated with poorer function in the same neurocognitive domains, in addition to the attention/executive domain, irrespective of age (ps < 0.05).

CONCLUSIONS

These data suggest that while heavy current alcohol consumption is associated with significant impairment in a number of neurocognitive domains, history of alcohol dependence, even in the absence of heavy current alcohol use, is associated with lasting negative consequences for neurocognitive function.

Effects of cigarette smoking and alcohol use on neurocognition and BDNF levels in a Chinese population

OBJECTIVE

Few studies have examined the potential interactive effect of both smoking and drinking on cognition. Brain-derived neurotrophic factor (BDNF) plays a critical role in cognition. This is the first study to examine the neurocognitive consequences of cigarette smoking combined with chronic alcohol consumption and their relationship to serum BDNF levels in a Chinese Han population.

MATERIALS AND METHODS

We recruited 191 healthy male subjects, including 47 isolated smokers, 31 isolated chronic alcohol users, 58 combined smokers and chronic alcohol users, and 55 non-smokers and non-alcohol users. We then compared the repeatable battery for the assessment of neuropsychological status (RBANS) scores and serum BDNF levels in these four groups.

RESULTS

When compared to the non-smoking + non-alcohol-using group, the smoking group performed worse on immediate memory, attention, language, and RBANS total score. There were no significant differences in the RBANS scores between the alcohol-using group and non-smoking + non-alcohol-using group, or between the smoking group and smoking + alcohol-using group. We did not find an association between BDNF and smoking or drinking status or between BDNF and cognitive performance. In the smoking group, there was a significant correlation between BDNF and carbon monoxide concentration, and between BDNF and the Fagerstrom Test for Nicotine Dependence (FTND) total score.

CONCLUSIONS

Our results suggest that smoking is associated with cognitive decline, but not with BDNF levels in a normal population. However, smoking severity is positively associated with BDNF levels. Concomitant alcohol use does not worsen the cognitive decline caused by smoking.

Successful smoking cessation is associated with prefrontal cortical function during a Stroop task: A preliminary study

Although many smokers try to quit, relatively few are successful in their attempts. Here we investigated whether the ability to quit smoking is related to behavioral and neural measures of cognitive control. A functional magnetic resonance imaging study with a counting Stroop task was used to measure cognitive control in ex-smokers (N=10) who had successfully quit smoking and smokers (N=10) who continuously failed to quit smoking. Behavioral results showed a significant Stroop effect in ex-smokers and smokers. Ex-smokers exhibited less Stroop interference, indicating superior cognitive control compared with smokers. Furthermore, when incongruent trials were contrasted with congruent trials, ex-smokers showed stronger BOLD activity than smokers in the right superior frontal gyrus and anterior cingulate cortex. Although the present study does not permit us to draw strong conclusions regarding causality, the results suggest that successful smoking cessation may be mediated by superior cognitive control.

Cognitive risk profiles for anxiety disorders in a high-risk population

The purpose of the present study was to identify subgroups of participants who may be at particularly high risk for anxiety pathology based on specific combinations of demographic characteristics and higher-order cognitive abilities in a population at disproportionate risk for deficits in cognitive abilities (i.e., smokers within the criminal justice system). Participants (N=495) provided demographic information, were administered a semi-structured diagnostic interview, and completed a number of measures assessing cognitive abilities. A receiver-operating characteristic (ROC) model using signal detection theory indicated that the strongest predictor of anxiety disorder diagnosis was race, with White participants having a 30.6% likelihood of diagnosis and participants in the non-White category (97% of which identified as Black/African American) having a 18.9% likelihood of diagnosis. Interestingly, the individual risk profile associated with the highest probability of having a current anxiety disorder was characterized by White participants with impaired response inhibition (58.6%), and the lowest probability of having a current anxiety disorder was among non-White males (13.9%). The findings, which indicated that White individuals with impaired response inhibition are at a disproportionately high risk for anxiety disorders, suggest a potential target for prevention and intervention.

Brain proton magnetic resonance spectroscopy of alcohol use disorders

This chapter critically reviews brain proton magnetic resonance spectroscopy ((1)H MRS) studies performed since 1994 in individuals with alcohol use disorders (AUD). We describe the neurochemicals that can be measured in vivo at the most common magnetic field strengths, summarize our knowledge about their general brain functions, and briefly explain some basic human (1)H MRS methods. Both cross-sectional and longitudinal research of individuals in treatment and of treatment-naïve individuals with AUD are discussed and interpreted on the basis of reported neuropathology. As AUDs are highly comorbid with chronic cigarette smoking and illicit substance abuse, we also summarize reports on their respective influences on regional proton metabolite levels. After reviewing research on neurobiologic correlates of relapse and genetic influences on brain metabolite levels, we finish with suggestions on future directions for (1)H MRS studies in AUDs. The review demonstrates that brain metabolic alterations associated with AUDs as well as their cognitive correlates are not simply a consequence of chronic alcohol consumption. Future MR research of AUDs in general has to be better prepared - and supported - to study clinically complex relationships between personality characteristics, comorbidities, neurogenetics, lifestyle, and living environment, as all these factors critically affect an individual's neurometabolic profile. (1)H MRS is uniquely positioned to tackle these complexities by contributing to a comprehensive biopsychosocial profile of individuals with AUD: it can provide non-invasive biochemical information on select regions of the brain at comparatively low overall cost for the ultimate purpose of informing more efficient treatments of AUDs.

Neurocognition in 1-month-abstinent treatment-seeking alcohol-dependent individuals: interactive effects of age and chronic cigarette smoking

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.

The effects of chronic cigarette smoking on cognitive recovery during early abstinence from alcohol

BACKGROUND

Alcohol use disorders are related to neurocognitive abnormalities during early abstinence in those seeking treatment for alcohol dependence (ALC). Considerable evidence indicates that chronic cigarette smoking is associated with multiple neurocognitive deficiencies. However, very little is known about the effects of chronic smoking on neurocognitive recovery during early abstinence from alcohol. We evaluated whether cigarette smoking interferes with cognitive improvement during early abstinence from alcohol, a period thought important for maintaining long-term sobriety.

METHODS

Neurocognitive functions previously shown to be adversely affected by both alcohol use disorders and chronic cigarette smoking were evaluated. We assessed 35 smoking ALC (sALC) and 34 nonsmoking ALC (nsALC) at approximately 1 and 5 weeks of monitored abstinence.

RESULTS

Although neither group was clinically impaired, both cross-sectional and longitudinal deficiencies were observed in sALC versus nsALC in processing speed, working memory, and auditory-verbal learning and memory. Lifetime alcohol consumption, medical, and psychiatric comorbidities did not predict neurocognitive performance or improvement across assessments. Within sALC, greater drinking and smoking severities were synergistically (more than additively) related to less improvement on visuospatial learning and memory. Former smoking status in the nsALC-mediated group differences in auditory-verbal delayed recall.

CONCLUSIONS

Chronic cigarette smoking appears to negatively impact neurocognition during early abstinence from alcohol. Although the cognitive deficiencies observed in this cohort were not in a clinical range of impairment, they should be considered to enhance treatment efficacy. Our findings lend support to integrating smoking cessation as well as the individual assessment of cognition into early ALC treatment. Additionally, there is a need to elucidate the effects of current and former smoking status in future reports of neurocognition.

A comprehensive assessment of neurocognition in middle-aged chronic cigarette smokers

BACKGROUND

The majority of studies investigating the neurocognitive consequences of chronic smoking have been conducted with adults 60 years and older. Therefore, the scope of neurocognitive dysfunction associated with chronic cigarette smoking in middle age (i.e., 30-60 age range) has not been fully delineated.

METHODS

Twenty-seven (44±9 years of age; 4 females) non-smoking and 30 smoking (49±8 years of age; 4 females) participants completed a comprehensive neurocognitive battery and measures of fine motor dexterity and postural stability. All participants were free of biomedical or psychiatric conditions that may have influenced neurocognitive and motor function.

RESULTS

Smokers performed significantly worse than non-smokers on the following domains: auditory-verbal and visuospatial learning, visuospatial memory, cognitive efficiency, executive skills, general intelligence, processing speed, fine motor dexterity and postural stability. The differences between smokers and non-smokers evidenced moderate to strong effect sizes and were not mediated by age, education, vocational level, estimated verbal intelligence or alcohol consumption. In smokers, a greater number of lifetime years of smoking was related to poorer performance on measures of cognitive efficiency, processing speed and visuospatial skills.

CONCLUSIONS

Results from this middle-aged cohort replicated previous research and provides novel findings indicating that chronic smoking was associated with inferior performance on measures of general intelligence, visuospatial learning and memory and fine motor dexterity. Research that relates measures of neurobiological function/integrity to neurocognition is needed to better understand the mechanisms contributing to the poorer performance across multiple domains demonstrated by smokers.

Measures of learning, memory and processing speed accurately predict smoking status in short-term abstinent treatment-seeking alcohol-dependent individuals

Aim: Chronic cigarette smoking appears to adversely affect several domains of neurocognition in those with alcohol use disorders (AUDs). The primary goal of this study was to identify which measures commonly used to assess neurocognition in AUDs accurately predict smoking status of individuals seeking treatment of alcohol dependence. Methods: Treatment-seeking alcohol-dependent participants (ALC; n = 92) completed a comprehensive neuropsychological battery after 33 ± 9 days of abstinence. Measures significantly different between smoking and non-smoking ALC were entered as predictors in binary logistic regression and discriminant analysis models, with smoking status as the dependent variable. Results: Smoking ALC performed significantly worse than non-smoking ALC on measures assessing processing speed, auditory–verbal and visuospatial learning and memory. Using these measures as predictors, a logistic regression model accurately classified 91% of smokers and non-smokers into their respective groups overall and accounted for 68% of the variance in smoking status. The discriminant analysis confirmed the findings from the logistic regression. In smoking ALC, smoking chronicity was inversely related to performance on multiple measures after controlling for lifetime alcohol consumption. Conclusions: Measures of processing speed, learning and memory robustly predicted the smoking status of ALC with high sensitivity and specificity during early abstinence. The results identified specific measures within a comprehensive neurocognitive battery that discriminated smoking and non-smoking alcohol-dependent individuals with a high sensitivity and specificity. The association of greater smoking chronicity and poorer performance on multiple measures after control for alcohol consumption suggests that chronic smoking adds an additional burden to neurocognitive function in those with alcohol dependence.

Addressing tobacco use disorder in smokers in early remission from alcohol dependence: the case for integrating smoking cessation services in substance use disorder treatment programs

Despite the declining overall rate of cigarette smoking in the general population in the United States, the prevalence of smoking is estimated to be as high as 80% among treatment-seeking alcoholics. The serious adverse health effects of tobacco and heavy alcohol use are synergistic and recent evidence suggests that smoking slows the process of cognitive recovery following alcohol abstinence. In addition, substantial evidence shows that treatment for tobacco dependence does not jeopardize alcohol abstinence. In this paper, we focus on the impact and treatment implications of tobacco dependence among treatment-seeking alcoholics through a review of five areas of research. We begin with brief reviews of two areas of research: studies investigating the genetic and neurobiological vulnerability of comorbid tobacco and alcohol dependence and studies investigating the consequences of comorbid dependence on neurobiological and cognitive functioning. We then review literature on the effects of smoking cessation on drinking urges and alcohol use and the effectiveness of smoking cessation interventions with alcoholic smokers. Finally, we offer recommendations for research with an emphasis on clinical research for enhancing smoking cessation outcomes in this population.

Decreased psychological well-being in late 'chronotypes' is mediated by smoking and alcohol consumption

Individuals are different 'chronotypes' with early 'larks' and late 'owls' forming the limits of a normal distribution in the population. We recently described that late chronotypes who suffer from a conflict between internal and external time ('social jetlag') suffer from more mental distress and are more likely to smoke than early chronotypes (Wittmann, Dinich, Merrow, and Roenneberg, 2006 . Social jetlag: mis-alignment of biological and social time. Chronobiology International, 23:497-509.). We performed a detailed analysis of the same database collected in 2002 comprising 134 daily smokers and 366 nonsmokers, scrutinizing the relationships between chronotype, smoking, and alcohol consumption as well as psychological well-being using a multiple mediation analysis. On average, smokers tend to be later chronotypes, report more sleep-associated psychosomatic symptoms, are more depressed, less balanced, and less vigilant. The mediation analysis suggests that only those late chronotypes who smoke and those who drink more suffer from increased psychological distress. We suggest that 'chronotype' is introduced as an additional factor in substance use, that is, when considering motives for smoking and drinking.

Neurocognitive consequences of surgery and radiotherapy for tumours of the pituitary

The management of patients with pituitary tumours requires a multidisciplinary approach utilizing a number of different treatment modalities that can impact upon pituitary function and may disrupt important areas of cerebral tissue that are important for normal neurocognitive function. Patients frequently report problems with memory and sustained attention that impact upon normal day-to-day life. At present it is unclear whether any causal link exists between treatments for pituitary tumours and abnormalities of memory and higher mental function. The domains of function affected in patients with pituitary tumours are memory and executive functions, which are involved in the control and direction of lower level, more automatic functions such as attention and motor skills. The evidence for disruption in these modalities is stronger for memory than for executive function. This may be due to variability in study design, insufficient tests and the potential inclusion of fundamentally different tumour types. The purpose of this review is to examine the available evidence to determine whether pituitary disease, its management, or subsequent complications are responsible for any neuropsychological deficits in pituitary patients. Furthermore we address methodological issues that may account for the apparent disparate neurocognitive data that exist in this patient group.

The relationships of sociodemographic factors, medical, psychiatric, and substance-misuse co-morbidities to neurocognition in short-term abstinent alcohol-dependent individuals

Co-morbidities that commonly accompany those afflicted with an alcohol use disorder (AUD) may promote variability in the pattern and magnitude of neurocognitive abnormalities demonstrated. The goal of this study was to investigate the influence of several common co-morbid medical conditions (primarily hypertension and hepatitis C), psychiatric (primarily unipolar mood and anxiety disorders), and substance use (primarily psychostimulant and cannabis) disorders, and chronic cigarette smoking on the neurocognitive functioning in short-term abstinent, treatment-seeking individuals with AUD. Seventy-five alcohol-dependent participants (ALC; 51+/-9 years of age; three females) completed comprehensive neurocognitive testing after approximately 1 month of abstinence. Multivariate multiple linear regression evaluated the relationships among neurocognitive variables and medical conditions, psychiatric, and substance-use disorders, controlling for sociodemographic factors. Sixty-four percent of ALC had at least one medical, psychiatric, or substance-abuse co-morbidity (excluding smoking). Smoking status (smoker or nonsmoker) and age were significant independent predictors of cognitive efficiency, general intelligence, postural stability, processing speed, and visuospatial memory after age-normed adjustment and control for estimated pre-morbid verbal intelligence, education, alcohol consumption, and medical, psychiatric, and substance-misuse co-morbidities. Results indicated that chronic smoking accounted for a significant portion of the variance in the neurocognitive performance of this middle-aged AUD cohort. The age-related findings for ALC suggest that alcohol dependence, per se, was associated with diminished neurocognitive functioning with increasing age. The study of participants who demonstrate common co-morbidities observed in AUD is necessary to fully understand how AUD, as a clinical syndrome, affects neurocognition, brain neurobiology, and their changes with extended abstinence.

Are treated alcoholics representative of the entire population with alcohol use disorders? A magnetic resonance study of brain injury

Almost all we know about neurobiological brain injury in alcohol use disorders has been derived from convenience samples of treated alcoholics. Recent research has demonstrated more comorbid conditions, poorer psychosocial functioning, and higher dependence levels in treated alcoholics than in their treatment-naive counterparts. Thus, it is not clear whether neuroimaging results from convenience samples of treated alcoholics can be generalized to the entire population with alcohol use disorders. We compared 35 treated alcoholics at 1 week of abstinence (ALC) and 32 treatment-naive heavy drinkers (HD) on regional brain volumes and metabolite concentrations obtained by in vivo magnetic resonance at 1.5 Tesla to evaluate for potential group differences. Then, we evaluated whether comorbid cigarette smoking and common demographic and clinical variables mediated any existing neurobiological group differences. ALC demonstrated smaller lobar gray matter volumes and thalami than HD, exacerbated by chronic smoking. Furthermore, concentrations of N-acetyl-aspartate (an accepted marker of neuronal viability), choline-containing metabolites (involved in membrane turnover), and myo-inositol (a putative marker of glial cells and osmolyte) were lower in multiple brain regions of ALC compared to HD. The lower N-acetyl-aspartate concentrations in white matter of ALC versus HD were explained by average number of drinks per month over the year preceding study. However, the other group differences were not explained by common drinking, demographic, and clinical variables (used as covariates at the same time) or by excluding participants with comorbid mood disorders. Taken together, this suggests that the degree of brain atrophy, as well as neuronal and membrane injury in clinical samples of alcoholics cannot be generalized to the much larger population with alcohol use disorders that does not seek treatment.

Chronic Smoking Is Associated With Differential Neurocognitive Recovery in Abstinent Alcoholic Patients: A Preliminary Investigation

BACKGROUND

Approximately 50 to 90% of individuals in North America seeking treatment for alcoholism are chronic smokers. A growing body of evidence suggests that chronic cigarette smokers show a pattern of neurocognitive dysfunction similar to that observed in alcoholic patients. However, previous studies investigating neurocognitive recovery in abstinent alcoholic patients did not specifically consider the potential effects of chronic cigarette smoking.

METHODS

This study comprehensively compared longitudinal neurocognitive changes over 6 to 9 months of abstinence among 13 nonsmoking recovering alcoholic patients (ALC) and 12 actively smoking ALC. The neurocognitive performance of the alcoholic groups was compared with nonsmoking light-drinking controls (nonsmoking LD).

RESULTS

Nonsmoking ALC exhibited a significantly greater magnitude of longitudinal improvement than smoking ALC on measures of cognitive efficiency, executive skills, visuospatial skills, and working memory. Both nonsmoking ALC and smoking ALC demonstrated equivalent improvement on auditory-verbal learning, auditory-verbal memory, and processing speed. Nonsmoking LD showed no significant changes in neurocognition over time. In cross-sectional comparisons at 6 to 9 months of abstinence, nonsmoking ALC were superior to smoking ALC on measures of auditory-verbal learning, auditory-verbal memory, cognitive efficiency, executive skills, processing speed, and working memory. The longitudinal and cross-sectional neurocognitive differences observed between nonsmoking and smoking ALC remained significant after covarying for group differences in education, estimated premorbid intelligence alcohol consumption, and other potentially confounding variables. In smoking ALC, greater smoking severity was inversely related to longitudinal improvement on multiple neurocognitive measures.

CONCLUSIONS

These preliminary results suggest that chronic smoking may modulate neurocognitive recovery in abstinent alcoholic patients. More generally, chronic smoking may impact neurocognition in other conditions where is it a prevalent behavior.

Non-treatment-seeking heavy drinkers: effects of chronic cigarette smoking on brain structure

We previously reported [Cardenas, V.A., Studholme, C., Meyerhoff, D.J., Song, E., Weiner, M.W., 2005. Chronic active heavy drinking and family history of problem drinking modulate regional brain tissue volumes. Psychiatry Res. 138, 115-130] that non-treatment-seeking, active heavy drinkers (HD) demonstrated smaller regional neocortical gray matter volumes compared to light drinking controls; however, the potential effects of chronic cigarette smoking on regional brain volumes were not addressed. The goal of this retrospective analysis was to determine if chronic smoking affected brain structure in the non-treatment-seeking heavy drinking sample from our earlier report (i.e., Cardenas et al., 2005). Regional volumetric comparisons were made among age-matched smoking HD (n=17), non-smoking HD (n=16), and non-smoking light drinkers (nsLD; n=20) from our original sample. Quantitative volumetric measures of neocortical gray matter (GM), white matter (WM), subcortical structures, and cerebral spinal fluid (CSF) were derived from high-resolution magnetic resonance imaging. Smoking HD demonstrated smaller volumes than nsLD in the frontal, parietal, temporal GM, and for total neocortical GM. Smoking HD also demonstrated smaller temporal and total GM volumes than non-smoking HD. Non-smoking HD and nsLD did not differ significantly on GM volumes. Further, the three groups did not differ on lobar WM, subcortical structures or regional CSF volumes. These retrospective analyses indicate neocortical GM volume reductions in non-treatment-seeking smoking HD, but not in non-smoking HD, which are consistent with our studies in recently detoxified treatment-seeking alcohol-dependent samples.

Smoking and cognitive change from age 11 to 66 years: a confirmatory investigation

Previously we reported that smoking is associated with a small relative decline in cognition from childhood to old age. In this study we perform confirmatory analyses on a further wave of data collected from 298 of the participants, all with age 11 IQ scores, at age 66years, 2years after the original observations. Non-smokers scored a mean 4.9 memory test and 2.6 information processing speed test points and ex-smokers 3.5 memory test and 1.9 information processing speed test points higher than current smokers respectively over the two waves of testing, equivalent to 4-8% of mean test scores, adjusted for the effects of childhood IQ. Across tests a 100l/min higher Peak Expiratory Flow Rate was associated with a 3-4% higher test score at ages 64 and 66years. These data confirm the adverse effect of smoking on information processing speed, and provide new evidence for a similar adverse effect on memory for people in their mid-sixties.

Tobacco Use, Alcohol Dependence, and Cognitive Performance

Chronic alcohol abuse has long been associated with a mild, generalized pattern of cognitive decrements. However, it is important to note that problem drinking rarely occurs in isolation from abuse of other drugs. For people dependent upon alcohol, tobacco is one of the mostly commonly coabused substances. Recent research suggests that individuals with alcohol dependency may gravitate toward tobacco use, in part, because of the positive effects of nicotine on aspects of cognitive performance that may be compromised as a consequence of chronic alcohol misuse. In this article, the author focuses on the effects of nicotine on behavioral and electrophysiological indexes of cognitive performance, and the impact of these effects on alcohol-related cognitive decrements. The author discusses implications of these findings in the context of treatment and recovery of people with alcoholism.

A comparison of neurocognitive function in nonsmoking and chronically smoking short-term abstinent alcoholics

Approximately 70-90% of individuals in North America seeking treatment for alcoholism are chronic smokers. A growing body of evidence suggests chronic cigarette smoking alone adversely affects neurocognition in adults. However, few studies on the neurocognitive function of short-term abstinent alcoholics have specifically considered the potential effects of chronic cigarette smoking. In this study, 20 nonsmoking recovering alcoholics (nsRA) and 22 actively smoking recovering alcoholics (sRA) participants, matched on age and education, were contrasted on a comprehensive neurocognitive battery after 34+/-9 days of abstinence. nsRA were superior to sRA on measures of auditory-verbal learning and memory, processing speed, cognitive efficiency, and static postural stability. These group differences were not a function of group disparities in age, education, estimated premorbid verbal intelligence, lifetime alcohol consumption, or other measured comorbid psychiatric or medical factors. In sRA, longer smoking duration was negatively correlated with executive skills, visuospatial learning, general cognitive efficiency, and static postural stability. These results indicate that greater consideration of the potential neurobiological effects of current chronic smoking on neurocognitive functioning is warranted in studies of alcoholism and other conditions where smoking is a common comorbid factor.

Neuropsychological functioning and alcohol dependence

PURPOSE OF REVIEW

Alcohol dependence is a significant challenge to society and health-care services. The associated cognitive deficits are thought to affect behavioral control, therapy and liability to relapse. The present review demonstrates important new findings.

RECENT FINDINGS

Recent interest focused on compensatory functional circuits, components of executive functioning, externally induced attentional biases and the relevance of the cognitive deficits for therapy and rehabilitation.

SUMMARY

Recent studies found widespread compromised fronto-cortico-cerebellar circuits to underlie cognitive deficits. The inclusion of cerebellar structures to support functions traditionally associated with cortical and even prefrontal structures is important. However, most importantly, alcohol-dependent patients use additional and generally higher-order executive functions to compensate for deficient task performance. The compensatory mechanisms might help to explain close to normal functioning in basic cognitive domains enabled by support of executive components. But deficits in executive functions themselves might emerge more directly. New approaches concerning executive functioning, analyzing functional components of executive tasks, found response inhibition and decision-making to be impaired but normal performance in simple working memory tasks. Multiple withdrawals have been shown to lead to a higher degree of executive deficit. The causing mechanism underlying the attentional bias induced by alcohol-related words (stroop effect) is still under debate. Correlation of cognitive deficits with therapy outcome turned out to be weak. However, important interactions of cognitive deficits with personality, therapy-setting and successful coping, together with the finding that cognitive performance of alcohol-dependent patients could be enhanced by motivating instructions, might open new strategies in treatment planning and cognitive rehabilitation.