5. Drugs, psychobiology and motivation Flashcards
What is the disability adjusted life years?
The sum of years of potential life lost due to premature mortality and the years of life lost due to disability
What are some evolutionary reasons humans may engage in illicit substances?
Incur survival advantage- seen as the fourth biological drive
What are the four ways drugs can be administered?
Oral
Injection
Inhalation
Absorption through mucus membranes
How does oral administration work?
Dissolves in the stomach, carried to intestine, absorbed into bloodstream
How does injection administration work?
Injected into fat under skin (subcutaneous), muscle (intramuscular) or a vein (intravenous)
What are some negatives of inhalation administration?
Difficult to regulate dose, cause lung damage
How can drugs be absorbed though mucus membranes?
Nose, mouth, rectum
How do drugs have an impact on the CNS?
Psychoactive substances are lipid soluble and can dissolve in the fatty membrane of the brain
They are also small so they can pass through more easily
What is tolerance?
State of decreased sensitivity to a drug that develops because of use
What is withdrawal?
Sudden elimination can trigger adverse symptoms
What are the three elements that make addiction a chronic relapse disorder?
Heavy use- abstinence- relapse
What are the five stages of use that could cause addition?
- Experimental
- Causal
- Heavy use/abuse
- Compulsive
- Substance use disorder
Cost-benefit analysis (West, 2006)
What are some benefits of drug use?
Pleasurable high
Increased alertness
Socialisation
What are some costs of drug use?
Hangover/come down
Illness
Death
What does the Mesocorticolimbic pathway include? (reward circuit)
Mesolimbic- VTA, limbic forebrain, nucleus accumbens, amygdala, hippocampus
Mesocortical- VTA- prefrontal cortex
What is the paradox of substance abuse?
Individuals who are dependent on drugs often report they ‘want’ drugs but no longer ‘like’ them
Incentive Salience (Robinson and Berridge)
What did they find?
Repeated use leads to an increase in DA activity
They found that exposure to drug related cues also increases activity in the mesolimbic pathway
Exposure to cues increases wanting
What is another behaviourist theory that could describe how substance abuse disorders are formed?
Classical conditioning and incentive motivational processes
How can associative learning explain substance abuse?
Explains why pathological drug use may just be restricted to certain environments
What symptoms do addicts show?
Cognitive impairment, poor decision making, lack of executive function, no inhibitory control
Why do addicts show poor inhibitory control?
Loss of function in frontal lobes
Can loss of function be treated?
Theoretically yes:
Brain plasticity suggests that deficits could be reversed or improved
