Neuropsychiatric disorders Addiction

Question 1

Explain addiction

Answer 1

Addiction is a colloquial term used by the public to describe an inability to stop doing/taking something.
Has been replaced medically by substance use disorder (DSM-V).
There is lots of debate over ‘addiction’ for things such as the internet, sex etc.
In the DSM-V, gambling is the only non-substance addictive disorder.

Question 2

What is the one common feature that all drugs of abuse share

Answer 2

• They increase dopamine release in the mesolimbic pathway.
• This is one of the key factors that make them rewarding.

Question 3

what are some of the broad range of mechanisms of drug abuse

Answer 3

• Nicotine binds to nicotinic receptors.
• Heroin binds to opioid receptors.
• Marijuana (THC being the active psychotropic) binds to cannabinoid CB1 receptors.
• Methamphetamine binds to the dopamine transporter.
• PCP and ketamine block NMDA (glutamatergic) receptors

Question 4

What is Methamphetamine and its effects

Answer 4

Methamphetamine (“ice”) is a stimulant drug that acts primarily to
increase dopamine release (indirectly).
- Blocks dopamine uptake at the dopamine transporter.
- Reverses the transporter so that it actively moves dopamine out of the cell.
- Impairs vesicular uptake and storage.
- Affects noradrenaline and serotonin systems as well.

Question 5

How is methamphetamine use disorder diagnosed

Answer 5

Diagnosing methamphetamine use disorder?
School of Biomedical Sciences
Diagnostic criteria change over time.
Current standard is the DSM-V:
- 11 categorical descriptors
- Need to show at least 2 of these criteria.
- Has to be within the last 12 months

Question 6

What are the 11 categories to diagnosed methamphetamine use disorder

Answer 6

1
Used larger amounts/longer
Progression of drug use “using more than you meant to”.
2
Repeated attempts to quit/control use
They actively want to stop using but can’t.
3
Much time spent using
Often daily or even multiple times per day.
4
Craving
Urges to use the substance.
5
Neglected major roles to use
Didn’t go to work, school, or chores at home etc.
6
Social/interpersonal problems related to use
Continuing to use, even when it causes problems in relationships.
7
Activities given up to use
Giving up important social or recreational activities in order to use the substance.
8
Hazardous use
Using the substance again and again, even when it puts you in danger e.g., unsafe places, situations.
9
Physical/psychological problems related to use
Continuing to use, even when you know it is causing you problems e.g., depression, stomach discomfort etc.
10
Tolerance
Needing more in order to get the effects you want.
11
Withdrawal
Developing withdrawal symptoms that can be alleviated with the substance.

Question 7

What occurs to dopamine systems in continued use

Answer 7

Degeneration of dopamine systems contribute to continued use
* Decreased dopamine release means more drug needs to be taken to receive the same high.

• Decreased dopamine transporter most likely reflects less dopamine nerve terminals.
• May contribute to withdrawal and apathy when not using.
• Some evidence that levels begin to return to normal with prolonged abstinence.

Question 8

What drives ‘addiction’ and makes it hard to quit?

Answer 8

• There are many theories as to why someone starts using drugs excessively.
• Social situation.
• Socioeconomic status.
• ‘Risk taking’ behaviour (especially during adolescence).
• Biological differences can make someone continue to use after their first try:
• More sensitive to the drug so get a greater high.
• Differing metabolism so the high lasts longer.
• More sensitive to the side-effects/negative feeling of a drug.