Cognition and Long-Term Use of Ganja (Cannabis)

Schaeffer, James D.; Andrysiak, Therese; Ungerleider, J. Thomas

doi:10.1126/science.6972600

Cited by 32 publications

(7 citation statements)

References 10 publications

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“…In our experience, mean test scores following acquisition generally range between 35 and 55 correct in 90 sec. With paperand-pencil versions of the test, higher (Bond & Lader, 1973;Schaeffer, Andrysiak, & Ungerleider, 1981), lower (McClain, Kromhout, Zieve, & Duane, 1981), and comparable (Eckhardt, Parker, Noble, Pautler, & Gottschalk, 1979;Kornetsky, 1951) scores have been reported under nondrug conditions. Of special relevance to this comparison are studies with the paper-and-pencil version of the DSST that showed not only scores comparable to those found using the present method, but similar acquisition curves for repeated administration as well (Wittenborn, Flaherty, McGough, Bossange, & Nash, 1976;Wittenborn, Flaherty, McGough, & Nash, 1979).…”

Section: Discussionmentioning

confidence: 99%

An automated version of the digit symbol substitution test (DSST)

McLeod

Griffiths

Bigelow

et al. 1982

Behavior Research Methods & Instrumentation

355

218

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An automated version of the Digit Symbol Substitution Test is described that employs a relatively inexpensive, commercially available microcomputer to present and score the task. Advantages of the automated DSST include: (1) objective scoring of both speed and accuracy of test performance, (2) printed copies of test scores, (3) convenient administration under standardized test conditions, and (4) the capacity for repeated assessment of an individual's performance over time. Task performance data for individual subjects following doses of pentobarbital are presented; these data illustrate both the stability of task performance under constant conditions and the within-subjects sensitivity of task performance to experimental manipulations.The Digit Symbol Substitution Test (DSST), a component of the Wechsler Adult Intelligence Scale (Wechsler, 1958), is frequently used to measure associative ability. The DSST is also a popular instrument for the assessment of performance following administration of pharmacological agents. Indeed, it appears to be one of the more sensitive tasks used for this purpose (Hindmarch, 1980; McNair, 1973;Wittenborn, 1979).The DSST typically is administered as a paper-andpencil task. A subject is given a digit-symbol code in which each of nine digits is paired with a different symbol. On the same page (located below the code), a series of digits, selected from those in the code, is presented in an irregular order. The subject is instructed to draw the symbol that is appropriate for each digit in the space below each digit and to draw as many correct symbols as possible within a 90-sec test period.The present paper describes an automated version of the DSST that can be implemented easily on a commercially available personal microcomputer. This computerized version of the task offers advantages over the traditional pencil-and-paper version in terms of conve- nience, objective scoring, repeated measurement, and experimental control. METHODWith the automated DSST, the digit-symbol code is constantly displayed at the top of the video screen and the test digits are presented, one at a time, in the center of the screen. The subject's task is to enter, on the microcomputer keyboard, the geometric pattern of keypresses, shown in the digit-symbol code, which corresponds to the test digit. The microcomputer controls each 90-sec test session, scores the test, and stores the results; there is no need for a test administrator to be present during the test session.To implement the DSST program that controls the procedures described below, we use a TRS-80® Model I or Model III microcomputer (Radio Shack) with Level II BASIC and numeric key pad, a cassette tape recorder to load and save the program, and a peripheral interface package manufactured by the LVB Corporation (Lehigh Valley, Pennsylvania). The interface package includes a 1080-54 programmable timer card, 1080-01 bus extension, and a 1081-72 daisy chain cable. A Quick Printer II® (Radio Shack) is a useful system addition for providing printed rec...

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Section: Discussionmentioning

confidence: 99%

An automated version of the digit symbol substitution test (DSST)

McLeod

Griffiths

Bigelow

et al. 1982

Behavior Research Methods & Instrumentation

355

218

View full text Add to dashboard Cite

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“…Other studies have demonstrated persisting deficits in processing speed, attention, working memory, visuospatial skills, and executive functioning (Bolla et al, 2002;Croft et al, 2001;Ehrenreich et al, 1999;Lyons et al, 2004;Pope et al, 1997;Pope & Yurgelun-Todd, 1996;Solowij et al, 2002;Varma et al, 1988). However, some studies found no persisting cognitive deficits among adults with histories of heavy marijuana use (Carlin & Trupin, 1977;Pope et al, 2002;Schaeffer et al, 1981), and one study found that observed neurocognitive deficits normalized within a month of abstinence (Pope et al, 2001).…”

Section: Introductionmentioning

confidence: 98%

Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

Medina

Hanson

Schweinsburg

et al. 2007

J. Inter. Neuropsych. Soc.

260

259

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In adults, studies examining the long-lasting cognitive effects of marijuana use demonstrate subtle deficits in attention, executive function, and memory. Because neuromaturation continues through adolescence, these results cannot necessarily generalize to adolescent marijuana users. The goal of this study was to examine neuropsychological functioning in abstinent marijuana using and demographically similar control adolescents. Data were collected from 65 adolescent marijuana users (n 5 31, 26% females) and controls (n 5 34, 26% females) 16-18 years of age. Extensive exclusionary criteria included independent psychiatric, medical, and neurologic disorders. Neuropsychological assessments were conducted after . 23 days of monitored abstinence. After controlling for lifetime alcohol use and depressive symptoms, adolescent marijuana users demonstrated slower psychomotor speed ( p , .05), and poorer complex attention ( p , .04), story memory ( p , .04), and planning and sequencing ability ( p , .001) compared with controls. Post hoc analysis revealed that the number of lifetime marijuana use episodes was associated with poorer cognitive function, even after controlling for lifetime alcohol use. The general pattern of results suggested that, even after a month of monitored abstinence, adolescent marijuana users demonstrate subtle neuropsychological deficits compared with nonusers. It is possible that frequent marijuana use during adolescence may negatively influence neuromaturation and cognitive development. (JINS, 2007, 13, 807-820.)

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Section: Marijuana In Adultsmentioning

confidence: 99%

“…Adults who use marijuana chronically have demonstrated poorer performance on tests of learning and memory, attention, visuospatial skills, processing speed, and executive functions [5][6][7][8][9][10][11]. However, some investigations have found no performance decrements among heavy cannabis users [12][13][14][15].A meta-analysis examined 11 studies that met strict inclusion criteria, and ascribed impaired learning and memory to chronic marijuana consumption, but determined that other cognitive domains remain unaffected [16].Among heavy users, cannabinoid metabolites can remain detectable in the urine for an average of 27 days [17], and may continue to affect neural functioning. Pope and colleagues thus argue that deficits in attention, short-term memory, and psychomotor tasks following a short period of abstinence represent brief residual effects of cannabinoids, but that no persistent, long-term effects of chronic use exist in adults [12,13,18].…”

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confidence: 99%

The Influence of Marijuana Use on Neurocognitive Functioning in Adolescents

Schweinsburg

Brown²,

Tapert

2008

CDAR

217

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Marijuana use is common in adolescence, yet neural consequences have not been well delineated. This review seeks to ascertain whether heavy marijuana use in adolescence is associated with persistent neurocognitive abnormalities, and whether adolescents are more vulnerable to the impact of chronic marijuana use than adults.Among heavy marijuana using adults, neurocognitive deficits are apparent for several days following use, but may disappear after one month of abstinence. Studies of adolescent heavy users have identified impairments in learning and working memory up to six weeks after cessation, suggesting persisting effects, yet raise the possibility that abnormalities may remit with a longer duration of abstinence.Given ongoing neuromaturation during youth, adolescents may be more vulnerable to potential consequences of marijuana use than adults. This is supported by rodent models, which show greater memory impairments in animals exposed to cannabinoids as adolescents relative to those exposed as adults. Further, adult humans who initiated use in early adolescence show greater dysfunction than those who began use later. Together, these results suggest that adolescents are more vulnerable than adults to neurocognitive abnormalities associated with chronic heavy marijuana use; however, the impact of preexisting risk factors is unknown.Adolescents demonstrate persisting deficits related to heavy marijuana use for at least six weeks following discontinuation, particularly in the domains of learning, memory, and working memory. Further, adolescents appear more adversely affected by heavy use than adults. Longitudinal studies will help ascertain whether preexisting differences contribute to these abnormalities. KeywordsAdolescence; marijuana; cannabis; cognition; brain; development Marijuana is the most commonly used preparation of the psychoactive drug, Δ-9-tetrahydrocannabinol (THC), and is consistently the most widely used illicit drug among teenagers, and most users first experiment in adolescence [1]. While 17% of 8th graders have tried marijuana, by 12th grade almost half of teens have used [1,2]. After initial experimentation, many youths develop a regular pattern of use, with 20% of 12th graders reporting use in the past month, and 5% of 12th graders reporting daily use [2]. Adolescence *Address correspondence to this author at the Department of Psychiatry, University of California, 3350 La Jolla Village Drive, 151B San Diego, CA 92161, USA; Tel: (858)552-8585 x5592; stapert@ucsd.edu. NIH Public Access Author ManuscriptCurr Drug Abuse Rev. Author manuscript; available in PMC 2010 February 19. Published in final edited form as:Curr Drug Abuse Rev. 2008 January ; 1(1): 99-111. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscriptis also a period of continued neuromaturation, yet the potential neural consequences of marijuana use during these developments have not been well established, and may have implications for academic, occupational, and social achievements. This review will a...

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Cognition and Long-Term Use of Ganja (Cannabis)

Cited by 32 publications

References 10 publications

An automated version of the digit symbol substitution test (DSST)

An automated version of the digit symbol substitution test (DSST)

Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

The Influence of Marijuana Use on Neurocognitive Functioning in Adolescents

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