Lecture 3 Flashcards
What is a drug addiction ?
A chronic disorder in which drug-seeking & drug-taking behaviour persist despite serious negative consequences
What do addictive substances induce ?
They induce pleasant states or relieve stress
What does continued drug use induce ?
Induces adaptive changes in the CNS which leads to tolerance, physical dependence, sensitization, craving & relapse
What does genetic factors contribute to ?
Contribute to the risk of addiction, making some individuals more/less vulnerable
What are the groups of substances ?
- Depressants
- Stimulants
- Opioids
- Hallucinogens
What do depressants do ?
They result in behavioural sedation and relaxation
What drugs are included in depressants ?
- alcohol
- sedative (calming)
- hypnotic (sleep-inducing)
- anxiolytic (anxiety-reducing)
Do depressants increase or decrease CNS activity ?
They decrease CNS activity
Do depressants reduce or increase levels of physiological arousal ?
They reduce it
What are alcohol-related disorders ?
Cognitive, behavioural, biological & social problems associated with alcohol use & abuse
What is apparent stimulation ?
The initial effect of alcohol
* Initially feel more outgoing then gradually reaction time slows, judgement becomes poor, motor coordination is impaired
What path is travelled by alcohol throughout the body after ingestion ?
- Stomach - small amounts absorbed
- Small intestine- absorbed into the bloodstream
- Circulatory system distributes alcohol throughout the body
- Contacts major organs: heart, lungs ( vaporizes, is exhaled) & liver
What are the effects of alcohol on the brain ?
- GABA: may explain anti-anxiety properties of alcohol
- Glutamate system: may explain blackout/loss of memory period of intoxication
- Serotonin: may explain alcoholic cravings
- Dopamine: may explain pleasurable feelings experienced during alcohol consumption
What are the consequences of excessive drinking ?
- Liver disease
- Cardiovascular disorders
- Dementia
- Werinicke-Korsakoff syndrome
- Fetal Alcohol syndrome
What is dementia ?
Deterioration of brain functioning
* can be a direct result of neurotoxicity or poisoning of the brain by excessive amounts of alcohol
What is Werinicke-Korsakoff syndrome ?
Results in confusion & loss of muscle coordination
What causes WKS ?
Caused by a deficiency in thiamine ( a vitamin metabolized poorly by heavy drinkers )
What is Fetal Alcohol syndrome ?
Pattern of problems inluding learning difficulties, behaviour deficits & characteristic physical flaws
Who are more likely to drink heavily ?
Men (boo)
What is considered heavy drinking for men or women ?
- Men: 5+ drinks on one occasion at least once a month in the past year
- Women: 4+ drinks
How does the rate of alcohol use vary across countries ?
- Different attitudes towards drinking
- Availability of alcohol
- Family norms
- Physiological reactions
What are the predictors of later abuse ?
- Drinking at an early age (b/w 11-14) is predictive of developing later alcohol-related disorders
- Lacking (or experiencing milder) physiological response to the sedative effects of alcohol may increase the likelihood of later abuse
What do stimulants do ?
Enhance alertness and activity & elevate mood, arousal and concentration
What drugs are included in stimulants ?
- Amphetamines
- cocaine
- nicotine
- caffeine
What is caffeine use disorder ?
cognitive, biological, behavioural & social problems associated with the use & abuse of caffeine
What occurs when you take caffeine in small doses ?
Elevates mood & reduce fatigue
What occurs when you take caffeine in large doses ?
It causes insomnia
What does regular use of caffeine cause ?
- Tolerance
- Dependence
- Intoxication
- Withdrawl
What is tobacco-related disorders ?
cognitive, biological, behavioural & social problems associated with the use & abuse of nicotine
What patterns do nicotine produce ?
Produces patterns of dependence, tolerance, and withdrawl
What are the withdrawl symptoms of nicotine ?
- depressed mood
- insomnia
- irritability
- anxiety
- difficulty concentrating
- increased appetite
- weight gain
What are the consequences of nicotine ?
- high blood pressure
- increase risks of heart disease & cancer
What do amphetamines & cocaine do ?
- Increases blood pressure & pulse rate
- Induce the release of corticotropin - releasing factor & cortisol
What does long term use of amphetamines & cocaine cause ?
- irritability
- aggresive
- stereotyped behaviour
- paranoid-like psychosis
What are the mild withdrawl signs of amphetamines & cocaine ?
- insomnia
- depression
- lack of energy
- intense cravings
What are opiods ?
Family of addictive psychoactive substances that include natural opiates, synthetic variations & comparable substances that occur naturally in the brain
What is an opiate ?
Natural chemicals in the opium poppy that have a narcotic effect
What are opioid-related disorders ?
cognitive, biological, behavioural and social problems associated with the use and abuse of opiates and their synthetic varients
What drugs are included in opiods ?
- heroine
- opium
- codeine
- morphine
What can opioids cause ?
- euphoria
- drowsiness
- slowed breathing
- death
- can also reduce pain
What are the withdrawl symptoms of opioids ?
- excessive yawning
- nausea
- vomiting
- chills
- muscle aches
- diarrhea
- insomnia
What are the consequences of opioids ?
- mortality rates are 6-20 times more than the general population
- relapse is common
- many replace opiods with alcohol or other drugs
- increased risk of HIV infection
What do hallucinogens do ?
Alter sensory perception & produce delusions, paranoia & hallucinations
What are the physical symptoms of hallucinogens ?
blurred vision, rapid heart rate, etc
What categories does cannabis fall under ?
Depressant, stimulant, and hallucinogen
What are common reactions of cannabis ?
- altered perceptions
- mood swings
- heightened sensory experiences
What occurs when you take cannabis in large doses ?
- paranoia
- hallucinations
- dizziness
What can occur with the long-term use of cannabis ?
impaired memory, concentration, motivation & cannabis use disorder
What can synthetic marijuana cause ?
- hallucinations
- seizures
- heart rhythm problems
What are the symptoms of withdrawl of cannabis ?
restlessness, irritability & insomnia
are subtle & appear in heavy consumers
Where is dopamine highly concentrated ?
Ventral tegmental area ( VTA, midbrain, brainstem )
What is the mesolimbic pathway ?
Spans from the VTA to the nucleus accumbens (striatum) & other limbic regions
* Activation is necessary for experiencing reward and reinforcement
* Each drug increases the amount of dopamine released in this pathway differently
How is the release of dopamine stimulated ?
Both natural rewards (i.e: foods) & addictive drugs stimulate the release of dopamine from neurons of the presynaptic VTA into the nucleus accumbens ( brain’s pleasure centre) causing euphoria & reinforcement of that behaviour
What do dopamine transporters do ?
Removes dopamine from the synaptic cleft
What are the effect of drugs on dopamine ?
- All classes of drugs increase dopamine levels in the brain. but in different ways
- Some (i.e: alcohol and nicotine) indirectly excite dopamine-producing neurons in the VTA so they generate more action potentials
- Others (i.e: cocaine) act at the nerve terminal and bind to dopamine-transporter & block reuptake of dopamine
What is reuptake ?
Process that allows neurotransmitters to be taken back into the presynaptic neuron
What is the incentive sensitization theory
Incentive salience - as addiction develops, the addict develops an increase in “wanting” the drug, despite a decrease (or static) “liking”
What factors are involved in relapse & craving ?
- Re-exposure to the drug
- Exposure to enviromental stimuli previously paired with druge use ( conditioned drug cues )
- Exposure to enviromental stressors
What is the brain disease model of addiction ?
When fundamental biological processes are disrupted they can alter voluntary behavioural control & lead to self-regulation disorders
What are the criticisms of the brain model of addiction ?
- This view challenges values about self-determination & personal responsibilities which frame drug use as a voluntary act
- This view seems to be a way of excusing personal irresponsibility and criminal acts
- This view fails to identify genetic aberration or brain atypicalities that consistently apply to all individuals
What is operant conditioning ?
Type of learning that is controlled by the consequences of one’s behaviours
What is reinforcement ?
Any consequence that makes a behaviour more likely to occur ( strengthens the probability of the behaviour)
What is positive reinforcement ?
Presenting a pleasant stimulus following a behaviour we want to strengthen
What is classical conditioning ?
Form of learning in which one responds to a previously neutral stimulus that has been paired with another stimulus which elicits an automatic response
What is a unconditioned stimulus ?
Elicits an automatic response without prior conditioning
What is a unconditioned response ?
Automatic response to a stimulus that does not need to be learned
What is a conditioned stimulus ?
Initially neutral stimulus that comes to elicit a response due to association with an UCS
What is a conditioned response ?
Response previously associated with a nonneutral stimulus that is elicited by a (previously) neutral stimulus through conditioning
