Addiction Flashcards
What defines addiction?
Continued involvement with a substance or activity despite ongoing negative consequences which can be physical or psychological.
What is the difference between a habit and an addiction?
Habit – repeated behaviour in which the repetition may be unconscious.
Compulsion – if the habit occurs by compulsion and considerable discomfort is experienced if the behaviour is not performed, then the repetition or habit is considered an addiction.
What is process addiction?
Behaviours known to be addictive because they are mood altering:
- Money addictions
- Compulsive gambling
- Compulsive shopping and borrowing
- Work addiction
- Sexual
What is process addiction?
Severe substance use disorder.
Having severe symptoms such as:
- Tolerance - larger doses needed; lower dosage does not produce typical effect.
- Withdrawal - negative physical and psychological effects from stopping usage.
- Using more than intended amounts.
- Trying unsuccessfully to stop.
- Having physical or psychological problems made worse by drug.
- Experience problematic relationships.
How does addiction affect the brain?
Addiction gradually alters the structure and function of the brain.
An endpoint of a series of transitions from:
- Initial drug use - the drug is voluntarily taken because it has rewarding effects.
- Continued drug use leads to loss of control over this behaviour.
- Drug taking becomes habitual and ultimately compulsive which results in addiction.
What defines impulsivity?
A tendency to act on a whim, displaying behaviour characterised by little or no forethought, reflection, or consideration of the consequences.
What are the risk factors for addiction?
Which neurotransmitter systems are involved in addiction?
What are the main categories of abusive drugs?
How do drugs of abuse work in the brain?
Directly:
- Drugs of abuse may work via direct action on a dopamine receptor or dopamine transporter.
- Increased dopamine receptor activation e.g. cocaine.
Indirectly:
- Drugs of abuse may modulate dopamine via other receptor system and neurotransmitters that then modulate a different system.
- Downstream effects on dopamine from above systems e.g. alcohol.
- Binds to sub-receptors GABAA.
- Dopaminergic activity is eventually increased in the ventral tegmental area (VTA) by inhibiting GABAergic interneurons.
- Also binds to NMDA, endorphins, activates secondary messages and has direct serotonergic effects.
What are withdrawal symptoms?
Following a physiological adaptation to the presence of an agent (e.g. drug of abuse), tolerance occurs.
Withdrawal is the result of an abrupt cessation of the drug.
This syndrome involves:
- Disturbance of the autonomic nervous system.
- Activation of the thalamus.
- Release of corticotrophin releasing factor (CRF).
- Activation of the locus coeruleus (LC) - increased effect of noradrenaline.
Why is the balance of neurotransmitters during
intoxication and withdrawal important?
Why is methadone given to treat opioid addiction?
It a long-acting 𝜇-opioid receptor agonist that is administered as an oral solution.
The normal dose varies depending on the patient, but is in the range 10 to 40 mg daily.
Does not give individuals the same high heroin does.
Can block the effects of other opioids eg: if used at the same time as heroin the same high won’t be experienced. Thus decreasing the tendency to take heroin.
The downside is it is addictive itself as it actiavtes the reward pathway similarly to heroin.
Why is buprenorphine given to treat opioid addiction?
It is a partial agonist at 𝜇-opioid receptor but also has antagonist activity at 𝜅 (kappa) opioid receptors.
It is given as a sublingual tablet.
A combination preparation that contains buprenorphine and naloxone may be prescribed for addicts likely to inject the drug iv (the naloxone will produce severe withdrawal symptoms).
Only gives partial effects compared to heroin so you can come off slowly.
Why is naltrexone given to treat opioid addiction?
It is an opioid receptor antagonist which is used to prevent relapse in patients who have successfully withdrawn from heroin.
It will prevent the hedonic effects of heroin by blocking 𝜇-opioid receptors.
Doesn’t mimic effects of heroin like methadone & buprenorphine, instead it antagnises its effects.
It is recommended that it should only be given to patients who have not used heroin for more than seven days.
It is best suited for highly motivated, recently detoxified patients who desire total abstinence because of external circumstances - for instance, professionals or parolees.
