2 - Addiction

Question 1

what are the two classes of addiction?

Answer 1

substances
behavioural

Question 2

what is the 3 stage course of alcohol/drug uses, misuse, addiction?

Answer 2

• experimental use
• increasingly regular use
• spiralling dependence

Question 3

drug abuse

Answer 3

when a substance is used in a manner that does not conform to social norms - do not have to be dependent or addicted

Question 4

physical drug dependence

Answer 4

when an individual depends on drugs for normal physiological functioning and abstinence produces physical withdrawal reactions

Question 5

psychological drug dependence

Answer 5

when acquiring or using drugs are a strong motivator of behaviour - compulsive use

Question 6

drug addiction

Answer 6

the term typically used to emphasies psychological dependence - not a clinical diagnosis

Question 7

how was drug misuse previously diagnosed? how is it diagnosed now?

Answer 7

• previously substance dependence
• now - substance use disorder

Question 8

how is substance use disorder classified?

Answer 8

mild - 2-3 symptoms
moderate - 4-5 symptoms
severe - 6-7 symptoms

Question 9

what area of the brain is the site of rewarding brain stimulation?

Answer 9

medial forebrain bundle

Question 10

describe the experiment whereby the role of the medial forebrain bundle was discovered?

Answer 10

• rat in box with lever
• when lever pressed it shocked brain via electrode
• when electrode was placed along medial forebrain bundle, it released dopamine
• this was pleasurable for the rat, and so the rat picked the lever that delviered the shock, over the lever that delivered the food - even to the point of starvation

Question 11

what is the acute effects of drugs of abuse on the nucleus accumbens?

Answer 11

substance use of amphetamines, cocaine, nicotine and morphine increase dopamine levels in the nucleus accumbens

Question 12

where does the medial forebrain run between?

Answer 12

ventral tegmental area and nucleus accumbens
(VTA-NA pathway)

Question 13

how does cocaine increase dopamine levels?

Answer 13

blocks the reuptake transporters on the post-synaptic neuron = increasing dopamine levels in synapse

Question 14

how do opiates affect the GABA neurone?

Answer 14

• inhibit GABA neuron
• GABA itself has an inhibitory effect on dopamine system
• acts as a double inhibition = initiation of nucleus accumbens

Question 15

how does tolerance to drugs of abuse occur?

Answer 15

• changes in endogenous dopamine release
• decreased receptors, receptor densensitisation and down-regulation

mechanisms not fully understood

Question 16

what is tolerance?

Answer 16

when an individual experiences a diminished response to a drug - there is a decreased effect or they need to take more for the same effect

Question 17

what are two common chronic effects of drug misuse?

Answer 17

tolerance
withdrawal

Question 18

what is withdrawal?

Answer 18

• sudden cessation produces symptoms
• changes to release and receptors means that functioning of pt depends on exogenous dopamine
• without external stimulation - normal function is compromised

Question 19

why do some people become dependent on drugs?

Answer 19

GXE interaction
(genetics and environment)
- particularly changes in dopamine genes and availability of drugs

Question 20

what is the 3 stage clinical management of drug dependence?

Answer 20

acute - managment of withdrawal
medium term - harm reduction (short-term/long-term substitution)
long term - maintaining abstinence

Question 21

what proportion of people who undergo short term rehab/detox will relapse within 1 year of treatment?

Answer 21

3/4

Question 22

what 3 drugs can be used to prevent relapse in opiate dependency?

Answer 22

• methadone - agonist
• buprenorphine - partial agonist
• naltrexone - antagonist

Question 23

when does fully developed withdrawal generally occur in drug dependent patients?

Answer 23

1-3 days after last use

Question 25

many deaths in opiate addicts are accidental overdoses after detox - why does this occur?

Answer 25

• detox removes tolerance
• when pt leaves detox facility and relapses, the quantity of the drug they take is too much for them now tolerance is gone

Question 26

what is the aim of opiate maintenance treatments?

Answer 26

• aims to replace/substitute heroine through once daily dosing

Question 27

why is opiate maintenance treatment beneficial?

Answer 27

• stops street use = reduces crime
• oral administration so reduces IV risks, HIV
• keeps pt in health care - easier to provide psychosocial treatment/support
• easier withdrawal when ready due to flexible dosing

Question 28

why is naltrexone not effective with pts?

Answer 28

• antagonist - blocks opiate receptor and leads to reduced dopamine activity
• reduces cravings
• but does not give pleasurable effect for pt, and so there is a real lack of adherence

Question 29

what is a risk associated with opiates that we want to avoid with substitution pharmacotherapy?

Answer 29

respiratory depression

Question 30

when might naltrexone be used clinically?

Answer 30

often only used in criminal justice system, where a person has to take it to avoid prison sentence

Question 31

what are 3 main psychological treatments involved in opiate addictions?

Answer 31

• motivational interviewing
• community reinforcement - pt can earn ‘tokens’/money with clean urine samples
• relapse prevention - CBT, skills training/practising saying no, alternative cognitions, lifestyle changes

Question 32

how are drugs classified in the UK?

Answer 32

class A
class B
class C
temporary drug classes - can be here for 1 year whilst they decide how it should be classified

Question 33

what is drug decriminalisation?

Answer 33

when drug use and posession does not result in criminal charges - may be replaced with civil penalties such as referral to eduction or treatmnet programme

Question 34

what was the findings of the 2010 lancet report into mortality and drugs?

Answer 34

alcohol was overall the most harmful drug when combining harm done to user and harm done to others

Question 35

describe the 4 stages of cocaine addiction, with reference to postsynaptic receptors and the amount of DA in the synapes?

Answer 35

1. normal - normal DA and normal postsynaptic receptors
2. acute use - increased dopamine in synapes, cocaine blockade at reuptake
3. chronic use - normal DA in synapse, cocaine blockade at reuptake, decreased postsynaptic receptors
4. withdrawal - decreased DA in synapse, decreased postsynaptic receptors

Question 36

Label this brain region that is involved in rewards and dopamine

Answer 36