cannabis and caffeine Flashcards
what is the age that cannabis/marijuana starts to be used?
18 years old
outline Brooks et al (1999) study into
- conducted longitudinal study
- assessed 776 ppts from New York
- found a correlation between cannabis use and usage of other drugs
- could argue cannabis is a gateway drug
what risk factors were identified that predispose individuals to use cannabis regularly?
(Gruber & Pope, 2002)
(motivations that moves users from initial to regular)
- family disturbances
- drug use by family/peers
- school performance
- age of onset
define tolerance
with multiple uses of that drug, you may need an increased dosage to reach the same effects
repeated exposure to drugs builds tolerance
what did Compton et al. (1990) find in human studies and tolerance?
found tolerance observed following repeated administration of marijuana or pure THC
what did Kirk & de Wit (1999), Lindgren et al (1981) find in human studies and tolerance?
found same level of ‘high’ in light/infrequent users compared to heavy/frequent users
what does research in human studies show about tolerance?
results are mixed as to whether tolerance develops with drugs in humans
outline Breivogel et al (1999) rat study into drug tolerance
- administered daily injection of THC
- over a 3 week period
- found progressive reduction in CB1 receptor density
- found cannabis agonist receptor activity
- found some brain areas = totally desensitised in 3 weeks
- shows tolerance building over regular drug use
define ‘dependence’ in relation to drugs
using a substance to the point of needing it to maintain optimal function
there are physiological effects on behaviour of withdrawing/not taking substance
identify signs of dependence
1/ difficulty taking substance
2/ craving for substance
3/ withdrawal symptoms when not taking substance
identify what abstinence of drugs triggers
- irritability
- anxiety
- depression
- sleep
- disturbances
- aggressiveness
- decreased appetite
outline Aceto et al. (1996) study into precipitated withdrawal
- precipitate withdrawal = gradually withdraw drug
- administered THC injections twice daily in rats
- rats then given SR 141716 (CB1 receptor antagonist)
- when cannabis withdrawn, rats showed symptoms of hyperactivity (shaking, face rubbing, scratching)
- shows signs of withdrawal in dependent rats
identify some treatments for drug tolerance & dependence
CBT
cognitive behavioural therapy
- ppts rewarded with vouchers for providing cannabis-free urine sample
what did Moore & Budney (2003) find about relapsing and withdrawal?
- found significant relapse in initial stages of withdrawal
- in first 30 days of abstinence, likely to relapse into first use
what did Haney et al. (2004) find in regards to withdrawal symptoms being eased?
- withdrawal symptoms can be eased by oral consumption of THC
- useful in short-term
- hard to achieve long-term abstinence with this treatment
identify psychological effects of cannabis use as found by Lynsky & Hall (2000)
chronic cannabis use has effect on education performance:
- more negative attitudes about school
- poorer grades
- increased absence from school
Amotivational syndrome:
- apathy
- aimlessness
- lack of productivity
identify psychological effects of cannabis use as found by Fergusson et al. (2003)
- regular cannabis use early in life predicts poor school performance and drop-out rates
identify psychological effects of cannabis use as found by Solowij et al. (2002)
- found cognitive deficits in long-term users of cannabis
- standardised tests of learning, memory and attention administered
- found long-term users deficient 1 and 7 days after exposure
identify psychological effects of cannabis use as found by Pope et al. (2001)
- found no difference between heavy users of cannabis and control group after 28 days
identify health effects of cannabis use
- more tar and carbon monoxide in a joint compared to cigarette
- THC suppresses immune function
- THC increases risk of bacterial infection
- smoking in women suppresses luteinising hormone (LH) release
- smoking in men reduces sperm count in men (heavy users)
what are some clinical applications of cannabis?
chemical compounds: dronabinol and nabilone used in medicinal purposes
dronabinol = antiemetic for chemo patients
nabilone = appetite stimulant in AIDS patients
cannabis used for chronic pain in MS, spinal cord injury, glaucoma
what are the 2 main sources of caffeine?
coffee
tea
what is the average adult daily intake of caffeine?
200 - 400 mg
how do kids consume caffeine?
- chocolate
- soft drinks
how is caffeine absorbed into the body?
- absorbed through gastrointestinal tract
- takes 30 - 60 minutes
what is caffeine converted to by the liver?
converted into metabolites
how is caffeine excreted?
- 95% excreted in urine
- 2-5% excreted in faeces
- rest excreted through saliva
what behavioural effect does caffeine have?
caffeine has biphasic effect
define biphasic effect
when a substance acts in two different ways as concentration increases
how does caffeine have a biphasic effect?
- a low dose of caffeine = stimulant, increasing locomotor activity
- a high dose of caffeine = decrease in activity
outline Smith et al. (1999) study into caffeine being more than just an arouser
- had ppts abstain from coffee, tea etc.
- gave ppts either a caffeinated or decaffeinated drink
- tested on variety of cognitive tasks
in caffeine group:
- more alert
- less tense
- decreased reaction time with and without distractors
in decaffeinated group: (compared to caffeinated group)
- less alert
- more tense
- quicker reaction times
outline Griffiths & Mumford (1995) study into tolerance and dependence in caffeine
- studied 3 groups of ppts
- caffeine maintenance group = consume caffeine capsules, this increased from 100mg to 200mg in second week of study
FOUND -> increased caffeine consumption during study showing development of tolerance - placebo group = sugar tablet
FOUND -> caffeine intake did not increase, no development of tolerance - caffeine withdrawal group = received caffeine pills for first two weeks and then placebo
FOUND -> reported more withdrawal symptoms, indicating development of dependence
identify health effects of chronic caffeine consumption
- increased blood pressure
- increased coronary heart disease
- decreased infant birth weight
