Cognitive effects cannabis

Parker LA, Gillies T THC-induced place and taste aversions in Lewis and Sprague-Dawley rats. Behav Neurosci 109 71-78, 1995 Pope HG, Yurgelun-Todd D The residual cognitive effects of heavy marijuana use in college students. JAMA 275 521-327, 1996 Robson P Therapeutic aspects of cannabis and cannabinoids. BrJ Psychiatry 178 107-115, 2001... 

The cognitive effects of cannabis are mild, and have many variables (dosage, chronicity of use, cognitive task employed, etc.). Of prime importance in such studies is the usage (or misusage) of the term impair-... 

Although significant advances have been made in recent years in the clinical evaluation of detrimental effects induced by developmental marijuana exposure, prospective longitudinal studies are currently underway. So far, they have preferentially investigated the cognitive effects of prenatal exposure to cannabis, with... 

When cannabis is smoked, usually in a cigarette with tobacco, the euphoric and relaxant effects occur within minutes, reach a maximum in about 30 minutes, and last up to 4 hours. Some of the motor and cognitive effects can persist for 5-12 hours. Cannabis can also be taken orally, in foods such as cakes (for example space cake ) or sweetmeats (for example hashish fudge) (8). 

Altered perception of the passage of time is the second common cognitive effect of cannabis (Chait Pierri, 1992). This is perhaps best described in statements like a few minutes seemed to pass like hours. Phe effect has been noted in both surveys and the experimental literature. However, the time distortion is not as pronounced in the research reports as it is in more subjective self-reports pro ided by marijuana users. 

This chapter reviews common research methods used to recruit, screen, and enroll research subjects, to administer cannabis to them, and to measure its physiological and psychological (including both subjective and cognitive) effects. Methods of monitoring for and minimizing possible adverse effects of cannabis (both physical and psychological) will also be described. 

Several physiological roles of endocannabinoids have been identified, including memoiy, cognition, movement, and pain perception (Stella et al. 1997). Elucidation of the endocannabinoid systems is essential to the understanding of the effects of cannabis. There are both similarities and some pointed differences between the effects of exogenous and endogenous cannabinoids. 

Cannabis use does not appear to induce a "hangover" syndrome like that produced with alcohol or sedative-hypnotics in terms of sleep effects, mood, psychomotor skills, or cognitive function (Chait 1990). 

The effects of cannabis on cognition is a complicated issue. Numerous studies have been conducted to measure the mental effects of cannabis, but many of these are fraught with methodological problems. Several variables must be controlled in this type of research, including the dosage and potency of cannabis used, route of administration (e.g., smoking, oral, etc.), chronicity of dose, and the subject population (nonusers, occasional users, chronic users) employed (table 10.7). Population makeup has a large effect on outcome because there have been differences demonstrated between naive and experienced cannabis users (Murray 1986). 

A study of experienced cannabis smokers tested them on cognitive measures using two doses (1.75% or 3.55%) and placebo (Wilson et al. 1994). The functions most sensitive to the effects of THC were mental processing speed (digit-symbol substitution) and reaction time. When compared with cannabis nonusers, chronic users of cannabis—with a mean duration of use of 6.76 years and an average daily intake of 150 mg of THC—were found to have slower reactions on perceptuo-motor tasks, but no differences on intelligence or memory tests (Varma et al. 1988). 

Cannabis has definite effects on cognitive functioning, but these have been overstated in many cases. The acute, short-term effects on cognitive... 

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