1. Genetic explanations of addiction
Learning objectives

2. Is there a genetic basis for addiction?
Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Is there a genetic basis for addiction?
As with depression there was a genetic link with the disorder the same goes for addiction
It may be passed down through
genes

3. Genes Addiction can run in families
Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Genes
Addiction can run in families
If addiction is genetic then this would help to explain why not everyone gets addiction to alcohol for example
Carmelli et al 1992 found that in identical twins, if one was a smoker then there was a higher chance the other would be too
As they share more genes than non identical twins this suggests that smoking could be genetic
Goodwin et al 1973 found that adopted children who had at least one biological parent with alcohol addiction would be more likely to be addicted themselves

4. Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Genes
This may suggest that one has inherited a gene from their biological parent that makes them an addict
Cadoret et al found that adopted children who shared a biological link with someone with alcohol problems were more likely to have alcohol problems themselves
They also found a link between alcohol abuse in adopted parents and the person becoming addicted so there is environment playing a role too

5. Is there a genetic basis for addiction?
Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Is there a genetic basis for addiction?
As a class we are going to complete an interactive task which will investigate the genetic causes of addiction and our chances of getting addiction based on our family tree

6. Is there a genetic basis for addiction?
Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Is there a genetic basis for addiction?
Using the template create a family tree based on the scenarios and code it as we saw in the task
Victor’s Mum is not a smoker however, his Dad is. Victor’s older brother Jake smokes and so did his Grandparents on his Dad’s side when they were alive. What is the likelihood of Victor smoking?
Rebecca's parents do not smoke and neither do her siblings Scott and Sally. Rebecca’s friends Milly and Tilly do smoke. What is the likelihood of Rebecca smoking?
Challenge
Create your own scenario and fill in the family tree

7. Is there a genetic basis for addiction? Victor’s family tree
Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Is there a genetic basis for addiction? Victor’s family tree

8. Is there a genetic basis for addiction? Rebecca’s family tree
Learning outcome:
I can explain how addictions can run in families and how it links to genetics
Is there a genetic basis for addiction? Rebecca’s family tree

9. Task Copy figure 3.7 on page 64 and answer question. Learning outcome:
I can explain how addictions can run in families families and how it links to genetics
Task
Copy figure 3.7 on page 64 and answer question.

10. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
This behaviour or object releases DOPAMINE which causes you to be HAPPY!
Draw yourself as a stick man/woman
Draw something that makes you happy
Draw your reaction to receiving this object

11. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
What is dopamine?

12. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Progress check:
Q1: What is dopamine?
Dopamine is a neurotransmitter that helps control the brain's reward and pleasure centres. 
Q2: What does dopamine control?
Dopamine also helps regulate movement and emotional responses, it enables us not only to see rewards, but to take action to move towards them. 

13. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
What does this demonstrate to us about drugs and dopamine?
Normally, after dopamine is released, it is recycled back into a dopamine transmitting neuron. However, cocaine binds to the dopamine, and does not allow it to be recycled. So there is a build up of dopamine.

14. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
People with low dopamine may be more prone to addiction. WHY?
Discuss in your groups
DRUGS
ALCOHOL

15. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Drugs cause dopamine deficiency.
Common street drugs which are easily available are one of the most common causes for it. Meperidine, a street drug causes the dopamine neurons breakdown and low dopamine levels.
Cocaine, Amphetamine etc., increase dopamine levels. Cocaine prevents the breakdown of dopamine. Continued use of these drugs, however, result in the reduction of number of dopamine receptors.

16. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Alcohol withdrawal.
Continuous use of alcohol in daily life results in impairment of dopamine levels in brain. When a person becomes addicted to alcohol, the brain areas producing dopamine are reduced.

17. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Q1: What is dopamine? Dopamine is a neurotransmitter that helps control the brain's reward and pleasure centres. Q2: What does dopamine control? Dopamine also helps regulate movement and emotional responses, it enables us not only to see rewards, but to take action to move towards them. Q3: What might people with low dopamine seek? Something such as drugs or alcohol to increase our dopamine levels so we feel happy.

18. Genes DDR2 is a gene that has been shown to be related in addiction
Many different addictions like gambling and alcohol have been linked to this gene (a variation of the gene called A1)
This gene is thought to affect the way the brain reacts to pleasure
Matinez et al 2004 found that a group of heavy users of cocaine were more likely to have a particular version of a dopamine receptor in the brains of people with this form of the gene

19. Is there a genetic basis for addiction?
Blum et al (1991) found children of alcoholics had an increased chance of showing the A1 variant. People who inherit the A1 variant on the DDR2 gene appeared to have fewer dopamine receptors in the pleasure centres of the brain.
People who inherit this A1 variant of the gene are more likely to become addicted to drugs which increase dopamine levels, compensating for the low levels by stimulating the few dopamine receptors which they have.

20. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
There are three sections to the model, these explain the process of addiction:
Initiation
Maintenance
Relapse
What do these words mean?

21. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Complete the worksheet provided, use the information sheets to help you!
Challenge:
Write a case study about Joe who is a drug addict and apply your knowledge of initiation, maintenance and relapse…

22. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
There are three sections to the model, these explain the process of addiction:
Initiation: this refers to the process where individuals start to become addicted.
Maintenance: this is the process where people continue to behave addictively even when there are consequences.
Relapse: this is the process where individuals who have managed to give up their addictive habits start to show signs and symptoms of the behaviour again.

23. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Initiation:
Research shows addictive drugs stimulate the reward circuit in the brain. Rewarding experiences trigger the release of dopamine and effectively tell the brain to ‘do it again’.

24. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Maintenance:
Exposure to drugs eventually results in a reduction in the activity of positive reward circuit this is because we create a tolerance to drugs.
The user no longer takes the drugs to gain pleasure, but instead takes them to avoid withdrawal symptoms (as we saw in operant conditioning).
As a result of tolerance to the drugs, higher levels of drugs are required to trigger the brain reward system.

25. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Relapse: eventually the desire for the drug may become more important than other things such as food, water etc.
Despite the fact that the drug may offer little or no pleasure now, the brain still receives difficult-to-resist signals of needing rewards that force the addict to take the drug again.
The frontal cortex has become less effective at making decisions and judging the consequences of actions.
This can increase the risk of relapse in addicts long after they have stopped taking a drug.

26. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
What is dopamine?
Dopamine is a neurotransmitter that helps control the brain's reward and pleasure centres. 
Dopamine also helps regulate movement and emotional responses, and it enables us not only to see rewards, but to take action to move toward them. 
Whiteboards…

27. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
What are the three elements that explain the process of dopamine in addiction?
Initiation
Maintenance
Relapse
Whiteboards…

28. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Which of the three elements is this…
Research shows addictive drugs stimulate the reward circuit in the brain. It tells the addict to ‘do it again’.
Initiation
Whiteboards…

29. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Which of the three elements is this…
The frontal cortex has become less effective at making decisions and judging the consequences of actions.
Relapse
Whiteboards…

30. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Which of the three elements is this…
Exposure to drugs eventually results in a reduction in the activity of positive reward circuit in the brain.
The user no longer takes the drugs to gain pleasure but takes them to avoid withdrawal symptoms.
As a result of tolerance to the drugs, higher levels of drugs are required to trigger the brain reward system.
Maintenance
Whiteboards…

31. What is the role of dopamine in addiction?
Learning outcome:
I can explain what dopamine is and its role in addiction
Complete the worksheet provided, use the information sheets to help you!
Challenge:
Write a case study about Joe who is a drug addict and apply your knowledge of initiation, maintenance and relapse…

32. Strengths and weaknesses of this explanation
Scientific evidence to support genetics
Twin studies and adoption studies
Explains why only some people become addicted
Reductionist
Carmelli 1992 looks at environment too which clearly plays a role
No single gene identified so hard to distinguish between

33. Exam question
Pg 65.