Reward and Substance use Flashcards
Drugs of abuse: what are the major stimulants?
Narcotics
Cannabis
Nicotine & Alcohol
Stimulants do what ?
arouses or accelerates activities
What are the ampthemines?
Amphetamine derivatives - methamphetamine (“Ice”), Methylenedioxymethamphetamine (MDMA, “E”), Methylenedioxyethylamphetamine (MDEA), Methylenedioxyamphetamine (MDA), Paramethoxyamphetamine (PMA, “death”)
Methylphenidate (Ritalin for ADHD)
* Nicotine (Tobacco)
* Psychostimulant: stimulates the brain
What do the narcotics due ?
nduces narcosis (sleep or stupor) = numbing
Give examples of narcotics?
Opium, Heroin (metabolised to morphine in CNS)
* Morphine
* Methadone
* Fentanyl
* Hydromorphone
* Meperidine
* Codeine
* Oxycodone
What do they Hallucinogens due?
produce hallucinations
Give eg of Hallucinogens
MDMA (“E”)
* Lysergic Acid Diethylamide (LSD “Acid”)
* 2,5-dimethoxy-4-iodoamphetamine (DOI)
* Phencyclidine (PCP , “angel dust”)
* Psilocybin (“magic” mushrooms)
* Mescaline (peyote cactus)
Drug Use Statistics:
Australian Institute of Health and Welfare
See slide 8
More older people taking drugs now in over 40’s ( 2001-2019)
Illicit Drug use in Youth, USA
see slide 9
slow INC from 8-12 grade
Drug Use Statistics:
Change in use from 2016 to
see slide 10
*amphetamine use is stable
Increase in “E “ use in males
See graph p11
upwards swing since 2016
Methamphetamine use is stable BUT
more potent forms used from 2013
Methamphetamine use is stable BUT
it is used at high frequently
see p 12- 13
why do we take drugs?
Curiosity/ offered it/ exciting
What do we continue?
Enjoyinh/ fun
enhance experience
exciting / improves mood
**Re -visit reward pathway: slides 17- 23
Nucleus accumbens (NA): Major Reward Area
Ventral Tegmental Area: VTA, Dopamine cell bodies
Effects of stimulants ?
Euphoria & well-being
* Increased alertness
* Increased self-confidence * Increased energy
Ecstasy (MDMA) is also an ENTACTOGEN (touchy feely) - promotes closeness to others
See Diagrams: Phamacology of diff drugs: slide 25-29
5 Side effects of stimulant use ?
- Seizures
- Depression & Anxiety
- Paranoia
- Psychosis
- Neurotoxicity
Pharmocology of Cannabis?
Active constituent of Cannabis is D9-Tetrahydrocannabinol (THC) THC binds to Cannabinoid receptors to increase DA release
in the nucleus accumbens
Cannabinoid receptors: CB1 & CB2 Anandamide is the natural ligand for these receptors
Effects of Cannabis
Cortex: motor/sensory,
Cingulate cortex: judgement
Hippocampus: blunts memory,
Cerebellum: blunts motor coordination
Pharmacology of Nicotine & Alcohol
Both increase dopamine release in nucleus accumbens by modulation of different receptor types:
* Nicotine - Nicotinic receptors (Acetylcholine)
* Alcohol - GABA-A receptor agonist
NMDA glutamate receptor antagonist
Modulates opioid peptide system (mu receptors)
Summary
All drugs of abuse are rewarding: * Euphoria
* Excitement
* Relaxation
All drugs of abuse increase DA in the Nucleus Accumbens * Cocaine blocks the DAT
* Amphetamines reverse the DAT
* MDMA (Ecstasy) reverses the SERT
* Cannabis increases DA via Cannabinoid receptors
* Nicotine increases DA via nicotinic receptors
* Alcohol increases DA via GABA-A and NMDA receptors
* All drugs of abuse have serious side effects from repeated use Ø ADDICTION
Ø PSYCHOSIS, DEPRESSION & ANXIETY
Chronic drug effects
Psychostimulant abuse:
Paranoid psychosis Similar to schizophrenic
Seizures
Depression Anxiety Parkinson’s like symptoms (MPTP)
Chronic drug effects
Psychostimulant abuse:
Paranoid psychosis Similar to schizophrenic
Seizures
Depression Anxiety Parkinson’s like symptoms (MPTP)
Review slides re drug effects on Serotonin transporters: slide 36- 39
Symptoms of repeated Ecstasy use?
- Depleted stores of serotonin in the terminals - Neurotoxicity(death) of serotonin cell terminals
- Chronic depressive and/or anxiety states
what drug caused reductions in social interaction?
MDMA
what are long term effects of MDMA?
INC anxiety
Outline effects of Methamphetamine & Neurotoxicity
Large doses and prolonged use of MDMA (ecstasy) result in the neurotoxicity of serotonin neurons
- Methamphetamine may also produce depletions in serotonin > depressive and anxiety symptoms
Methamphetamine has a greater effect on dopamine neurons
* Neurotoxicity of dopamine neurons (Nigrostriatal)
* Reduced dopamine increases the filter of the basal ganglia - information for movement can not get through
* Cases of Parkinson’s Disease (PD)-like symptoms have been reported
* Similar to the ‘frozen addicts’ who took MPTP by mistake
which drugs cause decreased DAT binding ?
Methamphetamine and Methcathinone (Meow Meow)
Chronic drug use has long-term behavioural consequences
due to sustained modulation of neurotransmitter systems
which drugs cause decreased DAT binding ?
Methamphetamine and Methcathinone (Meow Meow)
Chronic drug use has long-term behavioural consequences
due to sustained modulation of neurotransmitter systems
