Abstract
Alcohol abuse leads to a decline in cognitive ability. The purpose of this study is to examine the effect of alcohol consumption on cognitive ability. 12,589 participants of the study have been classified into two groups: the control group of non-drinking participants of the experiment and the experimental group of the regular consumers of alcohol. Their health and cognitive abilities were assessed five times over the ten years. It is found that the effects of alcohol consumption on cognitive ability are more obvious in the case of regular alcohol consumers.
Introduction
Alcohol abuse leads to a decline in cognitive ability. Sabia et al. (2014) conducted a study of “the association of midlife alcohol consumption assessed three times over ten years with subsequent cognitive decline” (p. 332). The purpose of the following research was to examine the effect of alcohol consumption on the cognitive ability of middle-aged people and to assess it five times. On the assumption that the cognitive ability of regular consumers of alcohol is lower than that of non-drinkers and the decline in cognitive ability is higher, null and working hypotheses were proposed. H0: The cognitive ability of regular alcohol consumers is the same as that of non-drinkers, and cognitive decline rates do not differ. H1: The cognitive ability of regular alcohol consumers is lower than that of non-drinkers, and the cognitive decline of regular alcohol consumers is higher than that of non-drinkers.
Method
The study of the Effects of Alcohol Consumption on Cognitive Ability was established in 2015 to examine the supposed decline in the cognitive ability of 12,589 medium-level managers. The study employed the repeated measures design for the experiment because it allows monitoring the changes of an individual over the prolonged period (Gleitman, Gross, & Reisberg, 2011, p. 41). Since the signs of cognitive dysfunction become apparent over time, the experiment was completed in 2025. The experiment was held in five phases. The length of the experiment from the first to final phase was ten years.
Design
The study employed the classic experimental design that has two groups: an experimental group that is “exposed to the experimental intervention” and a control group that is “left alone” (De Vaus, 2013, p. 13). The fact of alcohol consumption was the independent variable. The dependent variable showed the effect of alcohol consumption on cognitive ability (Zimbardo, Johnson, Lee, & McCann, 2012, p. 32). Thus, the independent condition of the control group was to avoid alcohol during the experiment, and the experimental group was to continue alcohol consumption. The extraneous variables included age, vascular risk factors, and smoking status (Coolican, 2014, p. 60).
Participants
The sample of the experiment is a group of medium-level managers aged 30-45 years in 150 companies based in London, United Kingdom. The total number of invitees was 12,589. In the first phase of the experiment, the participants were divided into two groups: the control group with non-drinking participants and the experimental group with regular consumers of alcohol. As a result, the control group consisted of 6,500 respondents, and the experimental group comprised 6,089 participants.
Materials
The materials for the experiment include print and digital versions of the three-page questionnaire, standard 30-word list for the free-recall test on memory, three-page list of mathematical tasks, 30-word list for the vocabulary test, and informed consent form.
Procedure
Before the experiment, the participants signed the informed consent form. This form included the identification of the researchers, identification of the purpose of the research, notation of risks to the participants, and guarantee of confidentiality to the participants (Creswell, 2013, p. 89). The experiment was held in five phases. In the first phase, the participants were offered to answer the questionnaire that included sections on lifestyle factors, health, demographic and work characteristics. Then they attended the medical examination where physicians registered the primary health indicators such as blood pressure, the amount of glucose in the blood, and markers of cardiovascular disease. These indicators were necessary to control the extraneous variable of vascular risk factors. After the medical examination, the participants passed the cognitive test that consisted of five tasks evaluating the cognitive function: 30-word free recall test, a series of 50 mathematical tasks, vocabulary test, phonemic and semantic verbal fluency tests. This procedure was repeated in 2020 during the third phase and in 2025 during the final phase. In 2017 and 2022, the participants only answered the questionnaires and sent their answers to researchers via e-mail.
Results
In the first phase, Global Cognitive Scores for the control group of non-drinking participants of the experiment and experimental group of the regular consumers of alcohol were estimated. The subsequent phases showed a decline in Global Cognitive Score for both groups. Table 1 presents the results of cognitive tests in the Global Cognitive Score that were made during the five phases of the experiment.
Table 1. Effects of Alcohol Consumption on Cognitive Ability
The analysis of these results shows that the total decline in the cognitive ability of the control group is –0,14 and of the experimental group is –0,22. The mean of the decline in the cognitive ability of regular alcohol consumers is higher than that of non-drinking participants, which is demonstrated in figure 1. The decline in the cognitive ability of non-drinking participants may be explained by such extraneous variables as age, vascular risk factors, and smoking status.
Discussion
In her study, Sabia et al. (2014) conclude that people consuming alcohol in midlife are “more likely to experience faster 10-year cognitive decline” (p. 337). Our findings are in agreement with previous studies demonstrating that the effects of alcohol consumption on cognitive ability are more obvious in the case of regular alcohol consumers. Thus, the working hypothesis has been confirmed.
References
Coolican, H. (2014). Research methods and statistics in psychology (6th Ed.). London: Psychology Press.
Creswell, J. W. (2013). Research design: Qualitative, quantitative, and mixed methods approaches. Thousand Oaks, CA: Sage publications.
De Vaus, D. (2013). Surveys in social research. New York, NY: Routledge.
Gleitman, H., Gross, J., & Reisberg, D. (2011). Psychology (8th Ed.). New York: Norton.
Sabia, S., Elbaz, A., Britton, A., Bell, S., Dugravot, A., Shipley, M.,… Singh-Manoux, A. (2014). Alcohol consumption and cognitive decline in early old age. Neurology, 82(4), 332-339.
Zimbardo, P. G., Johnson, R. L., Lee, R., & McCann, V. (2012). Psychology. New York, NY: Pearson.