Addiction

Question 1

What is addiction & ambivalance?

Answer 1

• Addiction is the continued repetition of a behaviour despite the advserse consequences.
• Addiction affects 2 million people in the UK
• Ambivalence: a hallmark of addiction - feel so good yet feel so bad.

Question 2

What is dependence syndrome?

Answer 2

• Use of a substance takes on a much higher priority that other behaviours that once had greater value. Salience.
• Evidence of Tolerance.
• Physiological Withdrawal Symptoms.
• Relief of symptoms by further use.
• Compulsion to use substance.
• Narrowing of repertoire (neglect of other interests)
• Reinstatement after abstinence.

Question 3

Explain the biaxial dependence/problem model of addiction

Answer 3

Question 4

What is the Stages of Change model in addiction?

Answer 4

Question 5

What makes a substance addictive?

Answer 5

• Pleasure producing potency
• Rapid onset of action
• Short duration of action
• Tolerance and withdrawal

Question 6

Is there an alcoholic gene?

Answer 6

• About 25% of the sons of alcoholics develop alcohol problems themselves
• Twin studies: 4 good studies show increased concordance for monozygotic over dizygotic
• Adoption studies - 3 to 4 times increase in risk in adoptees raised apart
• Metabolism of alcohol - 50% of asians due to flush reaction due to variant of acetaldehyde dehydrogenase gene
• Many small gene effects rather than single ‘alcoholic gene’
• There is a genetic contribution to heavy drinking and alcoholism but this is affected by social upbringing and personality factors.

Question 7

Explain Skinners Box

Answer 7

• Rat presses level to get food pellet - positive reinforcement
• Fixed interval schedule
• Variable interval schedule
• Rat presses level to turn off electric shock - negative reinforcement

Question 8

Give examples of variable reinforcement schedule

Question 9

Explain the pathway of dopamine in addiction/reward

Answer 9

• Dopamine produced in VTA
• Dopamine released into NA
• Mesolimbic DA pathway projects into frontal cortex as well.
• Also influences behavioural inhibition.
• Drugs work to reduce inhibitory function of frontal cortex

Dopamine levels spike with pleasurable activities e.g. sex, eating.

- All addictive drugs lead to increased dopamine levels in the nucleus accumbens.

- DA system linked to salience of an activity

- Addicts become less sensitive to natural reinforcers, drugs of abuse become more salient.

Question 10

What maintains addiction?

Answer 10

• Personality Factors - thrill seeking, impulsive, mood dysregulation
• Social factors - childhood trauma, drinking/drug taking amongst family and peers
• Altered physiology in continuous presence of drug - homeostasis
• Unpleasant effects when drug is absent - withdrawal

Question 11

What is end stage addiction?

Answer 11

• Overwhelming desire to take the drug, diminished ability to control drug seeking, reduced pleasure from biological rewards.
• Addicts take alcohol/drugs so often it becomes an almost automatic habit.
• Thought to be mediated by changes in the prefrontal cortex - overlearning of drug-related cues, impaired dop-down control.
• Can be triggered by drug-related cues even after many years of abstinence.