Long-term effects of frequent cannabis use on working memory and attention: an fMRI study

Abstract Objectives The long-lasting efficacy of working memory (WM) training has been a controversial and still ardently debated issue. In this meta-analysis, the authors explored the long-term effects of WM training in healthy older adults on WM subdomains and abilities outside the WM domain assessed in randomized controlled studies. Method A systematic literature search of PubMed, Web of Science, PsycINFO, Cochrane Library, ProQuest, clinicaltrials.gov, and Google Scholar was conducted. Random-effects models were used to quantitatively synthesize the existing data. Results Twenty-two eligible studies were included in the meta-analysis. The mean participant age ranged from 63.77 to 80.1 years. The meta-synthesized long-term effects on updating were 0.45 (95% confidence interval = 0.253–0.648, <6 months: 0.395, 0.171–0.619, ≥6 months: 0.641, 0.223–1.058), on shifting, 0.447 (0.246–0.648, <6 months: 0.448, 0.146–0.75, ≥6 months: 0.446, 0.176–0.716); on inhibition, 0.387 (0.228–0.547, <6 months: 0.248, 0.013–0.484, ≥6 months: 0.504, 0.288–0.712); on maintenance, 0.486 (0.352–0.62, <6 months: 0.52, 0.279–0.761, ≥6 months: 0.471, 0.31–0.63). Discussion The results showed that WM training exerted robust long-term effects on enhancing the WM system and improving processing speed and reasoning in late adulthood. Future studies are needed to use different tasks of the same WM construct to evaluate the WM training benefits, to adopt more ecological tasks or tasks related to daily life, to improve the external validity of WM training, and to identify the optimal implementation strategy for WM training.

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Training Working Memory of Children with and without Dyslexia

Children ◽

10.3390/children6030047 ◽

2019 ◽

Vol 6 (3) ◽

pp. 47 ◽

Cited By ~ 5

Author(s):

Claudia Maehler ◽

Christina Joerns ◽

Kirsten Schuchardt

Keyword(s):

Working Memory ◽

Memory Performance ◽

Operational Efficiency ◽

Third Graders ◽

Central Executive ◽

Phonological Loop ◽

School Age Children ◽

Control Group ◽

Long Term Effects

For the future school performance of a child in the fields of literacy and numeracy, the operational efficiency of working memory is a central predictor. Children affected by dyslexia exhibit specific deficits in the functions of working memory. A software application for elementary school-age children has been specifically developed for this study, attempting to improve the working memory’s operational efficiency. Based on Baddeley’s model of working memory (1986), the phonological loop, the visuo-spatial sketchpad, and the central executive were trained in 18 sessions over a period of six weeks. The group of test subjects undergoing this training was composed of third-graders, of which 43 were and 27 were not affected by dyslexia. The untrained control group was made up of 41 third-graders with dyslexia and 28 without dyslexia. While the short-term effects of the program could not be proven, the present analyses focus on long-term effects. The results obtained from a pre-test/follow-up design reveal that no long-term increases in performance regarding phonological and central executive working memory could be confirmed. Only the visuo-spatial Corsi block span exhibited a training effect over a period of three months. Additionally, training did not show any long-term effect of performance improvement, not even for a subgroup of children with dyslexia and an especially low working memory performance. Thus, even after this study, the question whether working memory can be trained or not remains partly unanswered but leaves us predominantly pessimistic.

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The metabolic implications of long term cannabis use in patients with psychosis

Epidemiologia e Psichiatria Sociale ◽

10.1017/s1121189x00001317 ◽

2008 ◽

Vol 17 (3) ◽

pp. 221-226 ◽

Cited By ~ 3

Author(s):

Farrah Mushtaq ◽

Valeria Mondelli ◽

Carmine M. Pariante

Keyword(s):

Body Weight ◽

General Population ◽

Endocannabinoid System ◽

Cannabis Use ◽

Long Term Effects ◽

Glucose Levels ◽

High Prevalence ◽

Vulnerable Patient ◽

Vulnerable Patient Group

SummaryAimsThe aim of this paper is to summarise the effects of cannabis use on appetite and energy balance, and to subsequently investigate the possible implications this may have in patients with psychosis, in whom a high prevalence of cannabis use has been reported.Methods– A narrative review based on the recent literature regarding cannabis use in the gen-eral population and patients with psychosis.Results– The short-term abilities of cannabis to increase appetite and body weight, through actions on the endogenous endocannabinoid system, have been well characterised throughout the literature. The long term effects of cannabis use are however unclear and only a minority of studies have been conducted in the general population with overall conflicting results. In terms of the effects of cannabis in patients with psychosis, there has only been one study to date that has investigated this and interestingly found cannabis use to be associated with increased body weight and blood glucose levels, thus providing evidence that cannabis use may be an important contributing factor to the reduced life expectancy, as is currently observed in this vulnerable patient group.Conclusions– It is clear from the literature that patients with psychosis are at a high risk of metabolic and cardiovascular disease in comparison to the general population. However the contribution of cannabis use to this risk is as of yet undetermined and further long term studies are need to confirm current findings and evaluate hypothesised mechanisms.Declaration of Interest: None.

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Interactions between long-term visual working memory and attention

Journal of Vision ◽

10.1167/5.8.422 ◽

2010 ◽

Vol 5 (8) ◽

pp. 422-422

Author(s):

D. A. Varakin ◽

D. T. Levin

Keyword(s):

Working Memory ◽

Visual Working Memory ◽

Memory And Attention

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Long-Term Recreational Cannabis Use Is Associated With Lower Executive Function and Processing Speed in a Pilot Sample of Older Adults

Journal of Geriatric Psychiatry and Neurology ◽

10.1177/08919887211049130 ◽

2021 ◽

pp. 089198872110491

Author(s):

Katie Stypulkowski ◽

Rachel E. Thayer

Keyword(s):

Older Adults ◽

Working Memory ◽

Executive Function ◽

Cognitive Function ◽

Processing Speed ◽

Bimodal Distribution ◽

Cannabis Use ◽

Short Term ◽

Small Pilot Study

More older adults are using cannabis for recreational and/or medical purposes, but most studies examining cognitive function and cannabis use do not include older adults. The current small pilot study sought to compare cognitive function and emotional functioning among adults age 60 and older who were regular, primarily recreational cannabis users ( n = 28) and nonusers ( n = 10). A bimodal distribution was observed among cannabis users such that they had either initiated regular use more recently (“short-term” users; ≤7 years, n = 13) or earlier in life (“long-term” users; ≥19 years, n = 15). Nonusers, short-term, and long-term users were not different in depression, anxiety, or emotion regulation, or alcohol use. Nonusers scored significantly higher than long-term users in executive function. Short-term users scored significantly higher than long-term users in executive function, processing speed, and general cognition. Additionally, greater recent cannabis use frequency was negatively associated with working memory. The current findings suggest that short-term recreational cannabis use does not result in differences in cognitive performance compared to nonusers, which may indicate that short-term use is relatively benign in older adults. However, longer duration of use is associated with poorer processing speed and executive functioning, and more recent cannabis use is associated with poorer working memory, which may impact older adults’ overall cognitive functioning.

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