amphetamines

Question 1

what are amphetamines

Answer 1

a synthetic psychostimulant that in terms of its chemical structure is similar to the neurotransmitter dopamine
- MDMA, meth, speed, Ecstasy, Molly etc
- prescribed by doctors for medical conditions

Question 2

methods of ingestion of amphetamines

Answer 2

• meth/speed taken orally and takes up to 30 mins for effects to occur
• typically a longer high than users of drugs such as cocaine

Question 3

behavioural effects of amphetamines

Answer 3

• heightened energy
• insomnia
• talkativeness
• irritability
• anxiety
• rambling
• anorexia
• euphoria
• alertness

Question 4

what neurotransmitters are involved with amphetamines

Answer 4

• inhibits transporter to increase synaptic levels but also stimulates DA release
• DA
• NA
• 5-HT - serotonin
• amphetamines actively release these neurotransmitters from nerve terminals and prevent reuptake of noradrenalin
• AMPH taken up by DAT, inside terminal provokes DA release, plus DAT functions in reverse to further release DA
• dopamine reuptake transporters are blocked by cocaine, this results in increased dopamine in the synaptic cleft, leading to behavioural symptoms of cocaine use

Question 5

mechanisms of amphetamines action in animal

Answer 5

• injected into nucleus accumbens - increased locomotor activity
• injected into striatum - increased stereotyped behaviours
• lesions in the areas cause decreased locomotor response or stereotyped behaviours

Question 6

what did Griffith et al find about amphetamine psychosis

Answer 6

• pps users but no prior history of psychosis
• given 10mg dextroamphetamine every hour for up to 5 days
• all became psychotic within 2-5 days
• delusions mostly auditory, also included poisoning from the experimenters

Question 7

behavioural effects of chronic use of amphetamines

Answer 7

• addiction and dependence
• cognitive impairment - memory, attention, decision making
• mood disorders - mood swings, irritability, anxiety, depression
• psychosis

Question 8

neurological effects of chronic use of amphetamines

Answer 8

• neurotransmitter imbalance
• cognitive impairment
• amphetamine induced psychosis
• neurotoxicity
• structural brain changes

Question 9

what did inada et al find about tolerance of amphetamines

Answer 9

• 11 days continuous iv infusion
• 20mg cocaine challenge
• schedule produced tolerance

Question 10

sensitisation of amphetamines

Answer 10

O’Daly
- enhanced neural responses - sensitisation leads to increased activity in reward-related brain regions
- heightened subjective effects - pps reported stronger subjective experiences after repeated exposure, correlating with changes in brain activity
- implications for psychiatric conditions- sensitisation provides insights into neurobiological mechanisms underlying addiction and psychiatric disorders like sz

Question 11

amphetamines and ADHD

Answer 11

• ritalin - commonly used for ADHD to increase focus and decrease inattention, hyperactivity and impulsivity
• low doses can reduce locomotor activity in both humans and rats
• evidence is unclear for long term benefits

Question 12

amphetamines and narcolepsy

Answer 12

• stimulate wakefulness during the day allowing individuals to function more adequately

Question 13

binge eating disorder and amphetamines

Answer 13

• help by increasing dopamine and norepinephrine in the synaptic cleft
• in preclinical studies of binge eating in rats, lisdexamfetamine was shown to reduce chocolate binge eating and reverse binge eating impulsiveness

Question 14

treatment strategies of amphetamines

Answer 14

• pharmacological - desipramine, DA antagonists
• behavioural - avoid triggers
• psychosocial - counselling and support