Reward and Substance use

Question 1

Drugs of abuse: what are the major stimulants?

Answer 1

Narcotics
Cannabis
Nicotine & Alcohol

Question 2

Stimulants do what ?

Answer 2

arouses or accelerates activities

Question 3

What are the ampthemines?

Answer 3

Amphetamine derivatives - methamphetamine (“Ice”), Methylenedioxymethamphetamine (MDMA, “E”), Methylenedioxyethylamphetamine (MDEA), Methylenedioxyamphetamine (MDA), Paramethoxyamphetamine (PMA, “death”)

Methylphenidate (Ritalin for ADHD)
* Nicotine (Tobacco)
* Psychostimulant: stimulates the brain

Question 4

What do the narcotics due ?

Answer 4

nduces narcosis (sleep or stupor) = numbing

Question 5

Give examples of narcotics?

Answer 5

Opium, Heroin (metabolised to morphine in CNS)
* Morphine
* Methadone
* Fentanyl
* Hydromorphone
* Meperidine
* Codeine
* Oxycodone

Question 6

What do they Hallucinogens due?

Answer 6

produce hallucinations

Question 7

Give eg of Hallucinogens

Answer 7

MDMA (“E”)
* Lysergic Acid Diethylamide (LSD “Acid”)
* 2,5-dimethoxy-4-iodoamphetamine (DOI)
* Phencyclidine (PCP , “angel dust”)
* Psilocybin (“magic” mushrooms)
* Mescaline (peyote cactus)

Question 8

Drug Use Statistics:
Australian Institute of Health and Welfare

See slide 8

Answer 8

More older people taking drugs now in over 40’s ( 2001-2019)

Question 9

Illicit Drug use in Youth, USA

see slide 9

Answer 9

slow INC from 8-12 grade

Question 9

Drug Use Statistics:
Change in use from 2016 to

see slide 10

Answer 9

*amphetamine use is stable

Question 10

Increase in “E “ use in males

See graph p11

Answer 10

upwards swing since 2016

Question 11

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

Question 12

why do we take drugs?

Answer 12

Curiosity/ offered it/ exciting

Question 13

What do we continue?

Answer 13

Enjoyinh/ fun
enhance experience
exciting / improves mood

Question 14

**Re -visit reward pathway: slides 17- 23

Answer 14

Nucleus accumbens (NA): Major Reward Area
Ventral Tegmental Area: VTA, Dopamine cell bodies

Question 15

Effects of stimulants ?

Answer 15

Euphoria & well-being
* Increased alertness
* Increased self-confidence * Increased energy

Ecstasy (MDMA) is also an ENTACTOGEN (touchy feely) - promotes closeness to others

Question 16

See Diagrams: Phamacology of diff drugs: slide 25-29

Question 17

5 Side effects of stimulant use ?

Answer 17

• Seizures
• Depression & Anxiety
• Paranoia
• Psychosis
• Neurotoxicity

Question 18

Pharmocology of Cannabis?

Answer 18

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

Question 19

Effects of Cannabis

Answer 19

Cortex: motor/sensory,
Cingulate cortex: judgement
Hippocampus: blunts memory,
Cerebellum: blunts motor coordination

Question 20

Pharmacology of Nicotine & Alcohol

Answer 20

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)

Question 21

Summary

Answer 21

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

Question 22

Chronic drug effects

Answer 22

Psychostimulant abuse:

Paranoid psychosis Similar to schizophrenic

Seizures

Depression Anxiety Parkinson’s like symptoms (MPTP)

Question 22

Chronic drug effects

Answer 22

Psychostimulant abuse:

Paranoid psychosis Similar to schizophrenic

Seizures

Depression Anxiety Parkinson’s like symptoms (MPTP)

Question 23

Review slides re drug effects on Serotonin transporters: slide 36- 39

Question 24

Symptoms of repeated Ecstasy use?

Answer 24

• Depleted stores of serotonin in the terminals - Neurotoxicity(death) of serotonin cell terminals
• Chronic depressive and/or anxiety states

Question 25

what drug caused reductions in social interaction?

Answer 25

MDMA

Question 26

what are long term effects of MDMA?

Answer 26

INC anxiety

Question 27

Outline effects of Methamphetamine & Neurotoxicity

Answer 27

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

Question 28

which drugs cause decreased DAT binding ?

Answer 28

Methamphetamine and Methcathinone (Meow Meow)

Chronic drug use has long-term behavioural consequences
due to sustained modulation of neurotransmitter systems

Question 28

which drugs cause decreased DAT binding ?

Answer 28

Methamphetamine and Methcathinone (Meow Meow)

Chronic drug use has long-term behavioural consequences
due to sustained modulation of neurotransmitter systems