Executive cognitive function and cessation of smoking among older smokers

The Synergistic Impact of Excessive Alcohol Drinking and Cigarette Smoking upon Prospective Memory

The independent use of excessive amounts of alcohol or persistent cigarette smoking have been found to have a deleterious impact upon Prospective Memory (PM: remembering future intentions and activities), although to date, the effect of their concurrent use upon PM is yet to be explored. The present study investigated the impact of the concurrent use of drinking excessive amounts of alcohol and smoking cigarettes (a "Polydrug" group) in comparison to the combined effect of the single use of these substances upon PM. The study adopted a single factorial independent groups design. The Cambridge Prospective Memory Test (CAMPROMPT) is a test of both time-based and event-based PM and was used here to measure PM. The CAMPROMPT was administered to 125 adults; an excessive alcohol user group (n = 40), a group of smokers who drink very little alcohol (n = 20), a combined user group (the "Polydrug" group) who drink excessively and smoke cigarettes (n = 40) and a non-drinker/low alcohol consumption control group (n = 25). The main findings revealed that the Polydrug users recalled significantly fewer time-based PM tasks than both excessive alcohol users p < 0.001 and smokers p = 0.013. Polydrug users (mean = 11.47) also remembered significantly fewer event-based PM tasks than excessive alcohol users p < 0.001 and smokers p = 0.013. With regards to the main aim of the study, the polydrug users exhibited significantly greater impaired time-based PM than the combined effect of single excessive alcohol users and cigarette smokers p = 0.033. However, no difference was observed between polydrug users and the combined effect of single excessive alcohol users and cigarette smokers in event-based PM p = 0.757. These results provide evidence that concurrent (polydrug) use of these two substances has a synergistic effect in terms of deficits upon time-based PM. The observation that combined excessive drinking and cigarette smoking leads to a greater impairment in time-based PM may be of paramount importance, given the key role PM plays in everyday independent living.

Smoking impedes executive function and related prospective memory

OBJECTIVE

This study assessed both executive function (EF) and prospective memory (PM) in a group of current smokers (CS) to observe whether deficits in both sets of memory processes co-existed in smokers, comparing this group with a group who had never smoked (NS).

METHOD

An existing-groups design was used to compare smokers with the NS group on a Reserve Digit Span Task (RDST) that measured EF and the Cambridge Prospective Memory Test (CAMPROMPT) measuring PM. Age, mood, other drug use and IQ were also measured and controlled for in the study.

RESULTS

After omitting anyone using an illegal substance and observing no between-group differences in age, gender, anxiety, depression, alcohol use and IQ, the CS group performed significantly worse on the RDST and recalled significantly fewer time-based and event-based tasks on CAMPROMPT, compared with the NS group.

CONCLUSIONS

Both EF and PM deficits were evident in the same cohort of CS when compared with a NS group, a finding which is novel in the current literature. Since both EF and PM are interrelated in that they share common resources in the brain, the finding that both sets of deficits co-existed in smokers suggests that persistent cigarette smoking impedes these underlying resources.

Exposure to second-hand smoke damages everyday prospective memory

AIMS

Prospective memory (PM: remembering future intentions and activities) is critical to everyday remembering. This study compared a group of never-smokers who reported regular exposure to second-hand smoke (the SHS group) with a group of current smokers (the CS group) and a group of never-smokers who reported never having been exposed to SHS (the non-SHS group) on objective PM.

DESIGN

An existing groups design was employed to compare the SHS, CS and non-SHS groups.

PARTICIPANTS AND SETTING

Twenty-four SHS, 27 CS and 28 non-SHS were tested on objective PM. All participants were university undergraduates aged between 18-30 years. All participants were tested individually in a laboratory setting.

MEASUREMENTS

The Cambridge Prospective Memory Test (CAMPROMPT) was used to assess objective PM. Age, other drug use, mood and IQ were also measured as covariates in the study.

FINDINGS

The non-SHS group recalled significantly more time-based PM tasks than the SHS group (means = 16.3 versus 13.7, P < 0.001) and significantly more than the CS group (CS mean = 11.6, P < 0.001); and the SHS group recalled significantly more time-based tasks than the CS group (P < 0.002). The non-SHS group recalled significantly more event-based PM tasks than the CS group (means = 15.2 versus 11.3, P < 0.002) with no significant difference between the non-SHS group and SHS group (SHS mean = 14.3, P = 0.234); and the SHS group recalled significantly more event-based tasks than the CS group (P < 0.001).

CONCLUSION

Non-smokers exposed to second-hand smoke may suffer impairment in time-based prospective memory.

Smoking-related prospective memory deficits in a real-world task

BACKGROUND

Smokers, previous smokers and a never smoked group were compared on self-reported and real world prospective memory (PM - the cognitive ability of remembering to carry out particular actions at some future point in time).

METHODS

Twenty-seven current smokers, 24 people who had never smoked and 18 previous smokers were compared using an existing groups design. Scores on the long and short term PM subscales of the Prospective and Retrospective Memory Questionnaire (PRMQ) and scores on a Real World Prospective Memory Task (RWPMT) constituted the dependent measures. Smoking and other drug use were assessed by a Recreational Drug Use Questionnaire. The Hospital Anxiety and Depression Scale gauged levels of anxiety and depression. The National Adult Reading Test measured IQ, and retrospective memory was measured using the PRMQ. Gender, age, anxiety and depression, IQ, alcohol use and the retrospective memory scores, were measured as covariates and controlled for in the analysis.

RESULTS

A series of univariate ANCOVAs were applied to the main PM data across the three groups, controlling for variations in age, gender, mood, IQ, alcohol use and retrospective memory scores. These revealed no significant between-group differences on self-reported PM; however smokers recalled significantly fewer action-location combinations than the never smoked and previous smoker groups on the objective RWPMT.

CONCLUSIONS

Existing smokers showed reduced performance on RWPMT when compared to the never smoked group and previous smokers. Real-world PM impairments should be added to a growing list of neuropsychological sequelae associated with persistent smoking.