Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Brain and Behaviour > Substance abuse disorders > Flashcards

Substance abuse disorders Flashcards

1
Q

What is substance abuse?

A

a pattern of drug use in which people rely on a drug chronically and excessively and not for therapeutic reasons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does addiction/ dependence refer to?

A

being physically dependent on a drug in addition to abusing it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is positive reinforcement?

A

• Positive reinforcement: the addition of a reinforcing stimulus following a behaviour that makes it more likely that the behaviour will occur again in the future
- Positive: addition of stimulant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the neural mechanisms of positive reinforcement?

A
  • Triggers the release of dopamine in the nucleus accumbens
  • Process of addiction begins in the mesolimbic dopaminergic system
  • Produce long term changes in other brain regions – starting with the ventral tegmental area (VTA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Give features of positive reinforcement in drug use

A
  • Reinforcing stimuli have a greater effect if it occurs immediately after the behaviour
  • Drug users prefer heroin to morphine as heroin has a more rapid effect – it is more lipid soluble
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the neural dopamine pathways?

A
  • Mesolimbic dopamine pathway
     Starts in ventral tegmental Area (VTA). Dopamine neurons project to nucleus accumbens
     Connects with nucleus accumbens (associated with striatum) and causes dopamine levels to rise
  • Mesocortical dopamine pathway
     Originates in VTA
     Travels to cerebral cortex (frontal lobes)
     Considered as part of the reward system
  • Dopamine levels increase reward seeking – it is released before stimulus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the neural mechanisms of positive reinforcement?

A
  • Changes in the VTA lead to increased activation in a variety of regions that receive dopaminergic input from the VTA
  • Synaptic changes that are responsible for the compulsive behaviours that characterise addiction occur only after continued use
  • The basal ganglia plays a critical role in instrumental conditioning (and movement – substantia nigra and Parkinson’s disease)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What structure in the basal ganglia is implicated in the neural changes we see as a result of substance abuse?

A

The dorsal striatum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is negative reinforcement?

A

the removal of something unpleasant?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is tolerance?

A

Decreased sensitivity from continued use?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is withdrawal and what does it do?

A
  • Withdrawal symptoms
     Generally the opposite of the drug itself
     The body may have started to compensate for the disturbed homeostatic mechanisms
  • Potentially maintains addiction
     Withdrawal symptoms are unpleasant, taking the drug removes them, producing negative reinforcement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What may negative reinforcement explain?

A
  • Explanation for start of addiction in some scenarios

 Taking a drug to deal with stress or other problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are cravings due to?

A
  • Potentially due to long-lasting brain changes
  • Drug-related stimuli can elicit classically conditioned responses in substance abusers, both physiologically and subjectively – cravings
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What was Frakens view on cravings?

A
  • Franken (2003) suggests craving and relapse are due to ‘attentional bias’ – cued by cognitive processes and increases in dopamine in response to drug stimuli
  • Franken’s (2003) review indicated dopamine increases in the nucleus accumbens (among other areas) in response to drug-related stimuli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What did Volkow use imaging to show?

A

dopamine increased in relation to cocaine-cues in the dorsal striatum but not the ventral striatum (where the nucleus accumebens is located)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Apart from dopamine what else is implicated in substance abuse?

A

• Prefrontal cortex has also been implicated

- Amount of activation of prefrontal cortex is inversely related to cocaine use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are features of heroin use?

A
  • Needle use
  • Transmission to unborn child (child will be born addicted to drug)
  • Uncertainty of strength and what it can be mixed with
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What type of drug is heroin?

A

An opiate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does stimulation of opiate receptors cause?

A

 Analgesia (periaqueductal grey matter) – pain relief
 Hypothermia (preoptic area)
 Sedation (mesencephalic reticular formation)
 Reinforcement (ventral tegmental area and nucleus accumbens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do opiate related stimuli to?

A

trigger the release of dopamine in the nucleus accumbens (NAC)

21
Q

What did Wise et al. (1995) find about levels of dopamine in rats in regards to heroin?

A

increases of 150-300% in levels of dopaimine in rats’ NAC while the rat pressed a lever that delivered heroin
 Rats will also press a lever to inject opiates into the NAC or the ventral tegmental area – suggesting that the reinforcing effects of opiates are produced by the activation of neurons in the mesolimbic system and release of dopamine in the NAC

22
Q

Give features of Cocaine and amphetamines

A
  • Cocaine and amphetamines have similar behaviour effects but their sites of action are different
  • Likely highly addictive – Bozath & Wise (1985) reported that rats that self-administered cocaine were 3 times more likely to die than rats who self-administered heroin
  • Blocking dopamine receptors or destroying dopaminergic terminals in the NAC causes cocaine and amphetamines to lose much of their reinforcing effect
  • Highlights role or mesolimbic system
  • These drugs have quick acting reinforcing effects
23
Q

What does cocaine do?

A

Deactivates dopamine transporter proteins, blocking the reuptake of dopamine

24
Q

What does amphetamine do?

A

Also inhibits the reuptake of dopamine but directly stimulates the release of dopamine from terminal buttons as well

25
Is smoking addictive and how do we know?
Yes - Evidence that it is highly addictive, e.g. continuing to smoke after a heart attack, cancer surgery etc. - Animals will also self-administer nicotine
26
What does smoking stimulate?
Nicotinic acetylcholine receptors
27
What is nicotine associated with that reinforces smoking behaviour?
the release of dopamine in the NAC, reinforcing the behaviour
28
Damage to what area disrupts smoking addiction and how do we know??
Damage to the insula - Naqvi et al. (2007)  19 smokers with insula damage following acquired brain injury  50 smokers with no insula damage following acquired brain injury  No difference in whether or not they had quit when they participated in the study  However, those who had insular damage were significantly more likely to have a disruption of smoking addiction - Insula shows highest association with smoking cessation
29
What are potential effects of alcohol?
 Mild euphoria (positive reinforcement)  Anxiolytic: reduces the discomfort of anxiety  Disinhibition (behaviour differs depending on the situation in which the individual consumes the alcohol)  Alcohol myopia: tendency for people to respond to near and immediate cues while ignoring more remote cues and potential consequences
30
What does alcohol do?
Increases activity in the dopaminergic neurons of the mesolimbic system
31
What are the two major sites of action with alcohol?
 Indirect antagonist at NMDA receptors |  Indirect agonist at GABBAA receptors (anxiolytic and sedative effects)
32
What can the removal of alcohol trigger and why?
- Increased sensitivity of NMDA receptors after suppressive effect of alcohol is removed can trigger seizures and convulsions (withdrawal symptoms) - Drugs which block NMDA receptors were shown to prevent the seizures in mice
33
Apart from the dopaminergic system what is the reinforcing effect of alcohol also due to?
- Alcohol can also trigger the release of endogenous opioids - Several studies have shown that drugs that block opiate receptors also block the reinforcing effects of alcohol in a variety of species, including rats, monkeys, and humans - The level of opioid receptors increases with abstinence and is thought to be related to cravings for alcohol
34
What is Korsakoff syndrome, who is it seen in and what happens with it?
- Often seen in alcoholics who are malnourished - Caused by a lack of vitamin B1 in the brain and exacerbated by the toxic effects of alcohol - Damage to areas of the thalamus and the mammillary bodies – structures important for encoding new memories - Type of amnesia
35
What receptors mediate most of the psychotropic effects of THC?
Cannabinoid type 1 (CB1) receptors
36
What does blocking CB1 receptors do?
Abolishes the high produced by smoking cannabis
37
What effect does THC have on dopaminergic neurones?
Stimulating effect
38
Apart from in cannabis what else do CB1 receptors have an effect on?
- CB1 receptors also have a probable role in the reinforcing effects of other drugs as well as cannabis  Blocking CB1 receptors in mice can abolish the reinforcing effect of cannabis, morphine and heroin and reduce the reinforcing effects of alcohol  Rimonabant, a drug which blocks CB1 receptors, decreases the reinforcing effects of nicotine
39
In large doses what does THC produce?
In large doses THC can produce anxiety and psychotic behaviours
40
What does CBD do?
- CBD has anti-anxiety and anti-psychotic effects. Doesn’t produce a high - Lots of evidence looking into CBD as a therapeutic drug
41
What influences whether someone is likely to take a substance and their likelihood of becoming dependent?
Genetic and environmental factors
42
What was Kendler et al.'s (2003) experiment about the specificity of genetic and environmental risk factors for use and abuse/dependence of 6 classes of illicit substance?
 Interviews of 1,196 male-male twin pairs  Found that environment plays a stronger role in drug use but genetics plays a stronger role in determining whether the person becomes addicted
43
What percentage is it estimated that the vulnerability to addiction can be attributed to genetic factors?
- It is estimated that 40-60% of the vulnerability to addiction can be attributed to genetic factors - Includes both variability in metabolism of the drug and variability in the sensitivity to the reinforcing effects
44
What environmental factors influence addiction?
Drug availability, low SES, poor parental support, stress
45
How is opiate addiction commonly treated?
- Opiate addiction is most commonly treated with methadone, an orally administered replacement drug - A newer drug, buprenorphine blocks the effect of opiates and produces only a weak opiate effect (buprenorphine + naloxone shown to be particularly effective – very limited abuse potential. If take heroin whilst on this combination withdrawal effects produced)
46
What is immunotherapy?
Vaccines specific to the substance abused (reward potential for specific substance becomes limited)
47
What is deep brain stimulation in regards to therapy for drug use?
DBS of the NAC had some promising effects, however it is a high risk procedure
48
Give features of TMS in terms of therapy for drug use
TMS is less invasive than DBS and has shown efficacy in reducing tobacco use but the effects on nicotine use diminished over time

Brain and Behaviour (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions