Lecture 14- Amphetamines Flashcards
What are amphetamines?
Amphetamines are a synthetic psychostimulant that in terms of its chemical structure is similar in nature to the neurotransmitter dopamine eg MDMA, ecstasy
Where can you get amphetamines?
Amphetamines for medicinal purposes are regularly prescribed by doctors for a range of medical conditions.
Also, similar naturally occurring chemical compounds eg Ephedra have been used in North America and southern Europe for +5,000 years
What are the origins of amphetamines?
Ephedra now banned appetite suppressant but in 1920s Ephedrine was used for asthma which led to synthetic substitute of amphetamine inhaler.
What are the methods of amphetamine use?
Recreational drugs such as meth/ speed are taken orally and takes up to 30 minutes for effects to occur.
Due to the half-life of the drug (7-30 hours) users typically experiences a longer high than users of drugs such as cocaine.
What does Griffith et al (1972) say about cocaine usage?
Studied amphetamine psychosis and found that all those given dosage for 5days became psychotic and that delusions mostly auditory, also included poisoning by experimenters and electric dynamo thought control
What are the 5 neurological effects of chronic cocaine usage?
Neurotransmitter imbalance
Cognitive impairment
Amphetamine-induced psychosis
Neurotoxicity
Structural brain changes
What is neurotransmitter imbalance?
(neurological effects)
Chronic use disrupts the regulation of dopamine, norepinephrine, and serotonin, leading to significant chemical imbalances and withdrawal symptoms
What are cognitive impairments in chronic amphetamine use?
(neurological effects)
Long-term use can impair memory, attention, and decision-making abilities, affecting daily life and mental health.
What is Amphetamine-Induced Psychosis?
(neurological effects)
Prolonged use can result in paranoia, hallucinations, and delusions, resembling symptoms of schizophrenia.
What is neurotoxicity?
(neurological effects)
Extended use can cause nerve cell damage, increasing the risk of seizures and strokes.
What are structural brain changes?
(neurological effects)
Chronic use affects neural plasticity, leading to changes in brain structure and function, impacting overall brain health.
What are the 3 effects of sensitisation that O’Daly (2014) found?
Enhanced neural response
Heightened subjective effects
Implications for psychiatric conditions
What is enhanced neural response in sensitisation?
Sensitization leads to increased activity in reward-related brain regions, such as the ventromedial caudate, during reward anticipation. This was measured using blood oxygen level dependent (BOLD) signal during functional MRI scans.
What is heightened subjective effects in sensitisation?
Participants reported stronger subjective experiences of amphetamines after repeated exposure, correlating with changes in brain activity. The study involved a sensitizing dosage regime followed by acute amphetamine administration
What are the implications for psychiatric conditions in sensitisation?
Sensitization provides insights into the neurobiological mechanisms underlying addiction and psychiatric disorders like schizophrenia, highlighting altered dopamine signalling
How do amphetamines affect clinical applications of ADHD?
Ritalin is commonly used to treat symptoms of ADHD to increase focus and decrease inattention eg low doses can reduce locomotor activity.
How do amphetamines affect clinical applications of narcolepsy?
Individuals with narcolepsy often struggle with daytime sleeping and amphetamines can stimulate wakefulness during the day allowing individuals to function more adequately
(Morgenthaler et al., 2007).
How do amphetamines affect clinical applications of being eating disorder?
Amphetamines help with this condition by increased 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 (Vickers et al., 2015; 2017).
What are some examples of mild/moderate effects of amphetamines?
Mood amplification
Restlessness
Hyperactivity
Inflated self esteem
What are some examples of sever effects of amphetamines?
Irritability
Extreme exhaustion
Extreme violence
Delusions of grandiosity
How do amphetamines affect neurotransmitters?
Amphetamines inhibits transporter to increase synaptic levels but also stimulates DA release.
How does amphetamines affect dopamine?
Unlike cocaine which just blocks catecholamine reuptake (dopamine), amphetamines also actively release these neurotransmitters from nerve terminals. They also prevent reuptake of Noradrenalin
What are the 4 behavioural effects of chronic amphetamine use?
Addiction and Dependence
Cognitive impairment
Mood disorder
Psychosis
How does cocaine affect addiction and dependence?
(behavioural effects)
Long-term use often leads to physical and psychological dependence. Users may feel unable to function without the drug and experience intense cravings.
How does cocaine affect impairments?
(behavioural effects)
Chronic use can impair cognitive functions, including memory, attention, and decision-making abilities. This can affect daily activities and overall quality of life.
How does cocaine influence mood disorders?
(behavioural effects)
Amphetamine abuse is associated with mood swings, irritability, anxiety, and depression. These mood disturbances can become more severe over time.
How does chronic cocaine use affect psychosis?
Extended use can lead to amphetamine-induced psychosis, characterized by paranoia, hallucinations, and delusions. This condition can be similar to schizophrenia and requires medical intervention.
