Cannabis‐related deficits in real‐world memory

Abstract

Background Research shows that cannabis users exhibit deficits in prospective memory (PM) and executive function, which persist beyond acute intoxication. However, many studies rely on self‐reports of memory failures or use laboratory‐based measures that may not mimic functional deficits in the real world. The present study aimed to assess real‐world memory functioning. Method Twenty cannabis‐only users and 20 non‐illicit drug users were recruited. Participants completed a substance use inventory and a mood scale, followed by a non‐immersive virtual reality task assessing PM and executive functioning. The task involved the participant playing the role of an office worker for the day and performing routine office duties. A number of subscales were used to assess facets of executive function (planning, adaptive thinking, creative thinking, selection, prioritisation) and PM (time‐based, event‐based and action‐based PM). Results Multivariate analysis of variance revealed cannabis users performed worse overall on the task, with poor performance on the planning, time‐based PM and event‐based PM subscales. In addition, indices of cannabis (length, dose, frequency, total use) were correlated with performance on these three subscales. Conclusions The present study expands on previously established research, providing support for the cannabis‐related deficits in PM and executive functioning, and the role of different aspects of cannabis use in these deficits. Copyright © 2012 John Wiley & Sons, Ltd.

Task Importance Affects Event-Based Prospective Memory Performance in Adults with HIV-Associated Neurocognitive Disorders and HIV-Infected Young Adults with Problematic Substance Use

“…To our knowledge, this is the first study to demonstrate adverse effects of cannabis use on PM in young adults infected with HIV. Such data are consistent with studies showing that cannabis use is associated with elevated PM failures in daily life (e.g., Bartholomew et al, 2010) and in the laboratory (e.g., Fisk & Montgomery, 2008; Montgomery, Seddon, Fisk, Murphy, & Jansari, 2012; cf. Cuttler, McLaughlin, & Graf, 2012) among seronegatives.…”

Neurocognition in college-aged daily marijuana users

“…Marijuana users demonstrate poorer retrospective recall on list-learning tasks (Bolla, Brown, Eldreth, Tate, & Cadet, 2002; Gonzalez et al, 2012; Hanson et al, 2010; Harvey, Sellman, Porter, & Frampton, 2007; Solowij et al, 2011; Takagi et al, 2011) as well as poorer memory for stories (Fried, Watkinson, & Gray, 2005; Medina et al, 2007; Schwartz, Gruenewald, Klitzner, & Fedio, 1989). Similarly, marijuana users display diminished memory for future actions assessed through prospective memory tasks (Bartholomew, Holroyd, & Heffernan, 2010; McHale & Hunt, 2008; Montgomery, Seddon, Fisk, Murphy, & Jansari, 2012). …”

“…Marijuana users show decreased planning ability on a Tower of London task (Grant, Chamberlain, Schreiber, & Odlaug, 2012) and a task of logical organization (Montgomery et al, 2012). Marijuana users demonstrate less flexibility and abstract reasoning ability than non-users (Bolla et al, 2002; Pope & Yurgelun-Todd, 1996), and decision-making tends to be more risky (Clark, Roiser, Robbins, & Sahakian, 2009; Grant et al, 2012; Solowij et al, 2012).…”

The K2/Spice Phenomenon: emergence, identification, legislation and metabolic characterization of synthetic cannabinoids in herbal incense products

“…In addition to the acute psychoactive effects reviewed previously, chronic use of marijuana has also been associated with development of dependence and addiction (Allsop et al, 2012), memory and learning disruptions (Montgomery et al, 2012; Taffe, 2012) and lowering of IQ scores (Meier et al, 2012). Teenagers and young adults appear to be especially vulnerable to these effects, most likely because they are undergoing robust neural development and synaptic restructuring (Gonzalez et al, 2012; Grant et al, 2012).…”