Drug Dependence Flashcards
What is addiction
A chronic disease characterised by drug seeking and use that is compulsive, or
difficult to control, despite harmful consequences.
define drug abuse
= is a pattern of drug use in which the users consume the substance in amounts or using methods which are directly or indirectly harmful to themselves or others
define drug dependence
= is an adaptive state that develops after repeated drug use and which results in withdrawal symptoms upon cessation of drug use
define drug tolerance
the diminishing effect of a drug which results after repeated administration at a set dose
define psychological dependence
dependence that involves emotional–motivational withdrawal symptoms (e.g. dysphoria, depression, anhedonia, restlessness)
define physical dependence
dependence that involves significant physical–somatic withdrawal symptoms (e.g. fatigue, nausea, seizures, pain, delirium tremens)
name some examples of - class A - Class B - Class C drugs
- Class A; Heroin, methadone, cocaine, crack cocaine, ecstasy, LSD, magic mushrooms,
- Class B; amphetamines, barbiturates, ketamine, methylphenidate, codeine, cannabis
- Class C; anabolic steroids, benzodiazepines, gamma hydroxybutyrate, gamma butyrolactone
Name the factors that are involved in development of addiction
- Environment
- Drug induced effects
- Genes
describe how genes can lead to addiction
of addiction
- Multitude of genetic factors that increase in the risk of developing addiction
- Some of these are linked to polymorphism and variants in the receptor for opioid
describe how drug induced effects can lead to addiction
- when you take a stimulate this causes pleasure and can cause dopamine release, those who become addicted have a high intensity stimulation of dopamine release in comparison to those who are not addicted who may find displeasure in taking the drug
What is the reward system in the body
The mesolimbic system is referred to as the reward system in the body.
Describe the mesolimbic system
It connects the ventral tegmental area to the nucleus accumbens, and is essential in
drug-dependence.
- it is the REWARD SYSTEM in the body
what is the origin of dopaminergic cell bodes in the midbrain
The VGA is the origin of dopaminergic cell bodies found in the midbrain.
name and describe the stages of addiction
- Binge/intoxication = this give positive reinforcement because this is pleasurable
- Withdrawal and negative affect = negative reinforcement gives you a negative reinforcement aspect
- Preoccupation/anticipation – conditioned positive and negative reinforcement
What are the symptoms of addiction
Bingeing, having loss of control.
Withdrawal.
Cravings.
Intoxifiacation.
describe the mechanism of action underlying withdrawal symptoms
- the ventral tenemental area releases dopamine that will stimulate the dopamine receptors
- neurones receive that input and project back releasing GABA and dynorphin which stimulate Kappa receptors
- Dynorphin will have an inhibitor effect on the VTA neurone and will trigger an unpleasant feeling so in order to get more reward again you need to stimulate it with the drug again
What are the structures in the brain that are involved in development of drug dependence
- Ventral tegmental
- Nucleus accumbens
- Amygdala
- Insula
- Prefrontal cortex
- Hippocampus
neurplasticity during….
Neuroplasticity during development of drug-seeking behaviour
- Brain connectivity changes occur during the development of addiction, there is a gradual involvement of many CNS structures and several neurotransmitter systems