Tory Clearwater, “Alcohol and Cannabis Co-Use: Evaluating Verbal Learning Performance in Adolescents and Young Adults”
Mentors: Krista Lisdahl and Ashley Stinson, Psychology
Alcohol and cannabis are the most widely co-used substances among adolescents and adults. Both alcohol and cannabis use have been linked to deficits in cognitive functioning, and while many studies have examined these effects independently, fewer studies have examined the effects of co-use. Current findings regarding co-use are mixed, as some studies suggest that cannabis may have neuroprotective effects, while others suggest that co-use contributes additively to cognitive deficits. The current study aims to investigate the relationship between number of past year alcohol and cannabis co-use days and verbal learning and memory performance in adolescent and young adults after a three-week abstinence period. The sample included 90 participants ages 16-25 (M age=21.14, 44% female). Past year alcohol, cannabis, and co-use days were assessed by self-report on the Timeline Followback, which measured frequency and quantity of individual substances. The California Verbal Learning Task-II (CVLT-II) was utilized to assess learning and memory on verbal tasks. From the CVLT-II, initial learning, total learning across Trials 1-5, and short and long delay free recall performance were used as outcomes. Separate multiple regressions were run to assess the relationship between past year substance use (alcohol use, cannabis use, and co-use days) and cognitive outcomes while controlling for age and sex. Results indicated that the overall models accounting for substance use and demographic variables were not significantly related to CVLT outcomes (p’s>.05). These findings are inconsistent with prior research suggesting negative effects of alcohol and cannabis use on cognition; however, these results align with other study findings that show after 1 week to a month of abstinence there are no significant differences in cognitive performance between substance users and healthy controls. Future longitudinal research is needed to disentangle independent and interactive contributions alcohol and cannabis use may have on cognition during adolescence.
Hi everyone! My name is Tory and I’m currently completing my last semester of my psychology degree here at UWM. I’ve been working in Dr. Lisdahl’s Brain Imaging and Neuropsychology lab for about two years now. I hope you enjoy my presentation, and feel free to leave any comments or questions below!
Hi Tory!! Excellent work on this! You presented the information in such a concise and easy-to-understand way! Your findings are very intriguing–I’d be curious to hear your thoughts on what a follow-up analysis might look like in only individuals who have co-used over the past year? And, if you would even have a large enough number of participants to even do that–I haven’t looked at the co-use data just yet! Also, what might be the role sustained abstinence is playing on your findings, and–potentially–at what time would we see this shift from significant differences (at 1-week out like in the literature you cited) versus these findings at 3-weeks out! Just some thoughts I had while looking this over. Keep up the great work!
Nice presentation, Tory. I enjoyed hearing about your research on alcohol/cannabis co-use. I wonder if your dataset might be able to provide some data on the rate at which co-use occurs. That is to say, how likely are folks who use alcohol first (or primarily) likely to simultaneously use cannabis; and vice versa. I’m wondering because you mentioned that your group was a bit thin on the poly-use criteria. It might be interesting, if possible, to see if one of these groups (initial alcohol vs. initial cannabis) is more likely to co-use. Also, I wondered whether you thought about using any other measures of cognitive (dys)function. There may be other metrics that might be more sensitive to the sort of cognitive decline you might expect to find. Great job!
Hi, Tory;
A very nicely done project! Relating it back to our class a bit, I wonder if research that focused upon attention might prove interesting? That is, would performance on something like a visual or verbal ANT show differences between co-users, single substance users, and non-users? Also of interest would be whether an impact upon attention (if there is one) persists after a period of abstention!
Nice work!