Topic 4 Flashcards
Addiction Defintion
Compulsive drug seeking behaviour and abuse
even when facing negative health affects
Acute affect of drug taking
Getting high
caused by changes in neural transmission
i.e changes in the amount of neurotransmitter being released or changes to the activation of receceptors
Long term effects of dug taking
Altered brain function
neuronal death
changes to white matter in the brain
adaptations at the molecular level
Reward circutory
Located in midbrain
Ventral Tegmental - releases dopaminergic neurotransmitters - these go to the nucleus accumbens and frontal cortex - release of dopamine in these areas causes pleasure - therefore reinforces the behaviour
Taking drugs increases the dopamine releases
stimulant
increases energy
depressant
Decreases energy
Reasons to take drugs
Stress, depression, social anxiety, curiosity, athletic performance
Characteristics of drug addiction
Dependency
Tolerance
Withdrawal
Dependancy
Occurs after chronic drug use causes physical adaptations to the brain. The brain essentially gets use to the drug being in the brain and therefore can’t function without the presence of the drug
Tolerance
When the user has to take a higher dose or use a drug more frequently to achieve the same high
Withdrawal
Is a sign that the body has become dependent on the drug
the person will exhibit negative affects when not taking the drug
Loss of control
Hallmark of addiction
due to structural and functional changes to the dorsolateral prefrontal cortex - the part of the brain that is responsible for judgement, planning and decision making
Factors influencing addiction
Genetic - genetic heritability, neuropsychiatric disorders ie anxiety, ADHD, PTSD or depression
Environmental - Issues with early life or school life, low socioeconomic, peers taking substances, lack of parental supervision, exposed to parents taking drugs at an early age, physical or sexual abuse
Reward circuitry name
Mesocorticolimbic Dopaminergic Reward System
Parts of MesoDopa reward system
1) Mesolimbic pathway = VTA to Nuclous accumben
2) Mesocortico pathway = VTA to prefrontal cortex
VTA
Ventral Tegamentum
Heroin and nicotine affects
Acts on dopaminergic receptors on cell body and dendrites - stimulates these receptors
Alcohol and cocaine affects
Blocks dopamine reuptake in synapse - binds to the dopamine transporters, preventing the dopamine from binding to them