Cannabis Physiopathological Effects

Central nervous system (CNS)

Psychological effects

Euphoria, dysphoria, anxiety, depersonalisation, aggravation of psychotic states

Effects on perception

Heightened sensory perception, distortion of space and time sense, misperceptions, hallucinations

Sedative effects

Generalised CNS depression, drowsiness, sleep, additive effect with other CNS depressants

Effects on cognition and psychomotor performance

Fragmentation of thoughts, mental clouding, memory impairment, global impairment of performance

Effects on motor function

Increased motor activity followed by inertia and uncoordination, ataxia, dysarthria, tremulousness, weakness and muscle twitching

Analgesic effects

Similar in efficacy to codeine

Antiemetic effects

In acute doses, effect reversed with larger doses or chronic use, increased appetite

Tolerance

To most behavioural and somatic effects, including the ‘high’ with chronic use

Dependence, abstinence syndrome

Rarely observed but has been produced experimentally following prolonged intoxication or administration of antagonists

Cardiorespiratory system

Heart rate

Increased with acute dosage, decreased with chronic use

Peripheral circulation

Vasodilation, conjuctival redness and postural hypotension

Cardiac output

Increased output and myocardial oxygen demand

Cerebral blood flow

Increased in the short term and decreased with chronic use

Breathing

Small doses stimulate, larger doses depress coughing but tolerance develops

Airways obstruction

Due to chronic smoking

Eye

Decreased intraocular pressure

Immune system

Impaired activity of bactericidal macrophages in lung and spleen

Reproductive system

Decreased sperm count and sperm motility in males, suppression of ovulation, complex effects on prolactin secretion, increased obstetric risks

Cannabis abuse screening test (CAST)

During the last 12 months:

no (0)

yes (1)

1 Have you ever smoked cannabis before midday?

2 Have you ever smoked cannabis when you were alone?

3 Have you ever had memory problems when you smoke cannabis?

4 Have friends or members of your family ever told you that you ought to reduce your cannabis use?

5 Have you ever tried to reduce or stop your cannabis use without succeeding?

6 Have you ever had problems because of your use of cannabis (argument, fight, accident, bad result at school, etc.) ?

Which:

Measuring cannabis dependence based on DSM IV (Kandel et al., 1997)

(the numbers refer to DSM items, the following sentences to the corresponding question in the NHSDA)

1

Tolerance: during the past 12 months, for which drugs have you needed larger amounts to get the same effect; that is, for which drugs could you no longer get high on the same amount you used to?

2

Withdrawal: for which drugs have you had withdrawal symptoms; that is, you felt sick because you stopped or cut down on your use of them during the past 12 months?

3

Greater use than intended: which drugs have you felt that you needed or were dependent on in the past 12 months?

4

Unsuccessful efforts to cut down or control: during the past 12 months, for which drugs have you consciously tried to cut down on your use? During the past 12 months, for which drugs have you been unable to cut down on your use, even though you tried?

5

Great deal of time spent in using: have you used three joints or more nearly daily (three times or more a week) in the past 30 days; or 2 oz or more (86 joints or more or 43 g or more) in the past 30 days; or traded service for cannabis?

6

Reduction in social, occupational or recreational activities: as a result of drug use, at any time in your life, did you, in the past 12 months, get less work done than usual at school or on the job?

7

Continued using cannabis despite knowing it caused significant problems: as a result of drug use at any time in your life, did you in the past 12 months … (become depressed; have arguments/fights with family and friends; feel completely alone and isolated;