The purpose of the study
The main purpose of the study done by Vaughan et al. (2019) was to identify the connections between the loss of control in alcohol consumption and impulsive actions with the latest drinking history and intravenous self-administration of alcohol in non-dependent alcohol consumers utilizing the computer-assisted alcohol infusion system (CAIS). The study permits the evaluation of pharmacologically-triggered alcohol use while considering individual differences in the pharmacokinetics of the drug. Vaughan et al. (2019) argue that alcohol consumption disorder is related to disablement in control of alcohol use, judgment, and an increased tendency of impulsiveness. Poor impulse control is characterized by rapid unintended responses to intrinsic and extrinsic triggers without consideration of the destructive consequences of the responses. Individuals with a lack of impulse control are more likely to act rapidly toward various triggers resulting in both positive and negative effects.
The primary hypothesis
Vaughan et al. (2019) hypothesized that impaired control is a significant factor in the association between impulsiveness and alcohol consumption in both non-dependent and dependent drinkers. Alcohol-dependent consumers are expected to portray poor impulse control and generally higher tendencies to impulsiveness. Additionally, Vaughan et al. (2019) hypothesized that people wither higher self-reported loss of control are more likely to self-inject themselves with IV alcohol during the study. The researchers also assumed that young non-dependent alcohol consumers have a higher propensity to binge drink due to the positive urgency whereby an individual responds positively to elevated moods caused by alcohol. Lastly, the researchers expected individuals experiencing marked impaired control to portray higher subjective reactions to alcohol concerning liking and craving more IV alcohol injections.
The design to test the primary hypothesis
Vaughan et al. (2019) employed a correlational research design to test their hypothesis. The study design involves measuring different variables to establish a statistically consistent relationship between them. The research design was used to determine the relationship between loss of control and the tendency of intravenous IV alcohol self-administrated. The researchers sought to determine whether the participants with higher impaired control would portray increased subjective reaction to alcohol regarding craving more IV alcohol use. Additionally, Vaughan et al. (2019) studied the correlation between loss of control and reactivity to punishment and reward to identify other factors driving IV alcohol consumption. Mediation analysis was employed to examine the relationship between three variables: impulsivity, loss of control, and tendency to alcohol self-administration.
An advantage of the research design
One significant advantage of correlational study design is that the findings obtained can be easily classified. This is because this method of study employs a correlation coefficient to determine the extent of the relationship between the different variables. The results obtained can be easily classified into three classes: positive correlation, negative correlation, and zero correlation. A positive correlation indicates that the variables under investigation increase or decrease simultaneously. For instance, when one variable increases, the other variable increases with a similar proportion. A negative correlation shows an inverse relationship between the variables, while a zero correlation indicates a lack of specific correlation between the variables. In a negative correlation, one variable increases while the other one decreases, and vice versa. This classification makes it easy to understand the results obtained from a particular study.
A limitation of the research design
Results obtained from correlational studies can be less reliable due to external influences which might tamper with the findings. Generally, the study design does not guarantee that external factors (variables that are not under investigation) will stay out of the study. There is a possibility of obtaining unique outcomes that might interfere with the study, and these are not considered. For instance, in Vaughan et al. (2019) study, other causes of impulsivity, such as genetic mutations, were not considered which could have led to biased results. The unreliability of the results can also be caused by the subjects’ awareness that they are being watched by the observer. Individuals tend to act differently whenever they are aware that someone is watching their actions. Thus, the actions portrayed might not be completely genuine, and this could affect the results obtained.
The participants of the study
The study participants involved both male and female volunteers with no existing health conditions. A total of 48 individuals were involved in the study, with 23 males and 25 females. The participants were aged 21 to 45 years, and the recruitment was done via newspaper advertisements and the National Institutes of Health Normal Volunteer Office. The initial screening of the volunteers was done through a virtual interview, and then the participants were invited to the NIH Clinical Center for more screening. The screening entailed medical history, physical assessment, ECG, blood examination, test for illegal drugs, renal function tests, and latest drinking history. Clinical interviews were done to assess drug abuse and dependence. Volunteers with a history of alcohol or substance abuse were excluded from the study. Female participants were required to have normal menstrual cycles and negative pregnancy tests. Additionally, volunteers with major health issues such as HIV and Hepatitis infections were excluded from the study.
The variables measured in the study
The first two variables examined included impaired control and IV alcohol self-administration (IV-ASA), whereby Vaughan et al. (2019) sought to determine where impaired control increased the potential for IV alcohol use. The article describes impaired control as an inability to control one’s urge for alcohol consumption even though one wishes to abstain from it. The second variable studied was impaired control and subjective response, where the researchers sought to determine individual variations in response to the pharmacological effects of alcohol. The subjective reaction is described as individual variations in how their levels of sensitivity to the pharmacological actions of alcohol. The variable is believed to explain the differences in alcohol-drinking behavior and patterns in a given population.
Other variables include impulsivity and reactivity to punishment and reward. Vaughan et al. (2019) define impulsivity as susceptibility to fast, unintended responses to extrinsic and intrinsic triggers without considering the destructive impact of those responses. This variable was measured because other studies have illustrated that individuals depending on alcohol portray poor impulse control and a general increase in impulsivity. Impulsivity is also evident in non-dependent alcohol users. Reward sensitivity is a concept related to impulsivity and, therefore, it was measured in the study. According to the behavioral approach system, the stimulated trigger related to reward is evidenced in increased reward reactivity, and this is affected by the levels of alcohol consumption. Reward reactivity is a crucial factor in subjective reaction to alcohol since individuals with greater reactivity to reward are likely to show a greater craving for alcohol. This is an important factor in alcohol consumption; thus, explaining why researchers choose to measure it.
How the researchers operationalized each primary variable
Vaughan et al. (2019) examined the relationship between impaired control and IV alcohol consumption allowing the participants to undergo unlimited access to IV-ASA sessions for 150 minutes. The procedure took place in two steps, whereby the first step was directed. The volunteers self-administered alcohol intravenously by pushing a button to get four boosts of alcohol for the initial 10 minutes. The process permitted the subjects to comprehend the effect of intravenous administration of alcohol before they could be allowed unlimited access. This initial process was followed by a rest period which took 15 minutes and gave the participants sufficient time to experience the pharmacological effects of parenteral alcohol. After the rest period, the second phase of voluntary unlimited access lasting 125 minutes was done. Here, the participants were instructed that they could press the button any time they decided to experience a similar increase in blood alcohol concentration. This allowed them to increase their blood alcohol concentration whenever they felt like it during the session.
Drug Effects Questionnaires were used to collect subjective responses. DEQ estimates the subjective effects of specific drugs, and it was employed in the study to measure the liking and craving for more alcohol. It was measured at baseline and when the priming phase was taking place. DEQ was also measured eight times while the IV-ASA session was taking place. The researchers utilized mediation analysis to examine the correlation between impulsivity, loss of control, and reactivity to punishment and reward. Vaughan et al. (2019) concentrated on the positive urgency to represent impulsivity. Positive urgency refers to the propensity of an individual to react uncontrollably and rapidly to positive mood states. Positive urgency explains the dangerous and uncontrolled drinking behavior among some young individuals. Additionally, the researchers chose to use this concept to explain impulsivity since the study sample consisted of non-dependent alcohol consumers who use alcohol mostly for celebrations and less for stress.
The main results of the study
The results obtained in the study supported the researchers’ hypothesis that loss of control over alcohol consumption is related to an increased potential for intravenous alcohol self-administration in non-dependent consumers. The findings indicated that individuals with greater self-reported loss of control attained greater blood alcohol concentrations (BAC) and higher subjective responses during the IV-ASA session. This proved that subjective response to alcohol is affected by the loss of control. Vaughan et al. (2019) found that individuals with high blood alcohol concentration demonstrated a higher liking for alcohol and craved more alcohol during the session. Additionally, loss of control over alcohol was found to be a crucial factor in determining the correlation between positive urgency and self-administration of alcohol. Greater impairment in control was related to increasing positive urgency and reward reactivity. The mediation analysis indicated that the interrelation between positive urgency and high blood alcohol concentration was facilitated by loss of control and partly curbed by the subjective response.
The limitation of the study
The study employed a small sample which limited the ability to identify more intricate possible interactions and factors, such as gender differences and variations in the degrees of alcohol consumption. A lack of regard for such factors could have led to biased results. Small sample sizes are likely to decrease the reliability of results by increasing the margin of error. According to Vaughan et al. (2019), a larger sample size may have been necessary to increase the reliability of mediation results.
References
Vaughan, C. L., Stangl, B. L., Schwandt, M. L., Corey, K. M., Hendershot, C. S., & Ramchandani, V. A. (2019). The relationship between impaired control, impulsivity, and alcohol self-administration in nondependent drinkers. Experimental and clinical psychopharmacology, 27(3), 236.