Cannabis use, cognitive performance and mood in a sample of workers

Abstract

There are well documented acute and chronic effects of cannabis use on mental functioning. However, less is known about any effects on cognition within the context of work and everyday life. The aim of the study was to examine any association between cannabis use and cognitive performance, mood and human error at work. Cannabis users and controls completed a battery of laboratory based computer tasks measuring mood and cognitive function pre- and post-work at the start and end of a working week. They also completed daily diaries reporting their work performance. Cannabis use was associated with impairment in both cognitive function and mood, though cannabis users reported no more workplace errors than controls. Cannabis use was associated with lower alertness and slower response organization. In addition, users experienced working memory problems at the start, and psychomotor slowing and poorer episodic recall at the end of the working week. This pattern of results suggests two possible effects. First a 'hangover'-type effect which may increase with frequency of use. Second a subtle effect on cognitive function, perhaps more apparent under cognitive load and/or fatigue, which may increase with more prolonged use. The results also highlight the importance of the timing of testing within the context and routine of everyday life.

Acute and Chronic Effects of Cannabinoids on Human Cognition—A Systematic Review

“…Oral administration of THC [or IV (37)], nabilone, or dronabinol impaired psychomotor function in seven of eight studies (37,43,68,74,76,77,107), with only one study finding no significant impairment (73). Findings regarding the chronic effects of cannabis on psychomotor function are mixed, being reported as impaired (51,54,80,108), improved (48), and unaffected (46,78). Psychomotor function was impaired in users abstinent for 23-35 days (57,65,67,91), with a trend also after 12 months of abstinence (finger tapping) (64).…”

Alcohol hangover: a critical review of explanatory factors

“…In fact, hangover has been attributed to direct alcohol, alcohol metabolite, alcohol withdrawal or alcohol beverages congener effects (for a review, Swift and Davidson, 1998;Wiese et al, 2000). Moreover, several factors have also been reported as able to modify hangover, such as alcoholism vulnerability (Earleywine, 1993a,b;Span and Earleywine, 1999), concomitant use of other psychoactive substances (Vermeeren, 2004;Wadsworth et al, 2006) or psychosocial factors (Harbourg et al, 1993). Our goal in this work is to review the concept and etiology of alcohol hangover, and suggest that further research be done in those aspects that would improve our knowledge on such a phenomenon.…”

Risk of Marijuana Use in Male and Female College Student Athletes and Nonathletes

“…Because marijuana usually is smoked, the potential for cardiovascular and respiratory dysfunction is high (Ashton, 2001;Hall and Degenhardt, 2009). Smoking marijuana decreases alertness, lowers reaction time, and impairs memory (Ashton, 2001;Wadsworth et al, 2006). It accelerates muscle fatigue, thereby reducing exercise duration (Renaud and Cormier, 1986).…”