Addiction

Addictive drugs create a stimulation in a reward circuit in the brain which releases DA. For example, cocaine causes as massive activation of receptors in the mesolimbic pathway creating lasting (fake) memories or euphoria. which sets the brain to fail as it strives to get that hit again. 

Robinson and Berridge (1993) proposed the incentive sensitisation theory, which states that the repeated exposure to drugs leads to increasing sensitivity of their desirability. Once you take the drug, you've oversensitised your brain to it and it tells you it will feel better than it actually does. 

Down regulation maintains the use of the drug. It's a reduction of activity in the positive reward centres in the brain a a result from chronic exposure to drugs. Thie generates a chronic stress situation in which the addict must take the drug just to feel normal rather than good, (as they used to). 

Relapse - The desire may become more important than anything else. Even though the drug doesn't give much, if any, positive stimulation, the brain is still emitting messages to keep taking it, (maybe to feel at a normal state again - down regulation). The frontal cortex is damaged by the drug and no longer has much control over good decision making for the long term, and this can make the addict wrongly judging the danger of taking the drug again for a short term fix, and therefore they may relapse. 

• S - The model has practical, positive applications. 
• E - Taking addiction as a disease of the brain creates routes for treatments.
• E - If it's taken as a disease, it means that it may be possible to treat it with pharamcological methods; giving addicts more paths to take when going through treatment.
• L - This highlights the positive applications of regarding addiction as a disease. 
• S - The disease model is supported by research.
• E - Volkow (2003) claims that those who grow up with stimulating environments are more protected from addiction.
• E - This is because when people get a positive stimulation from natural things and produce dopamine rushes from natural things they do not need to look for another source or be stimulated by any artificial factors.
• L - This supports the disease model to addiction. 
• S - The model may be seen as reductionist. 
• E - The model ignores environmental and social factors.
• E - This means that it ignores other extraneous variables and only focuses on the idea of addiction being a disease and that's simply it.
• L - This weakens the validity of the theory and indicates that it is reductionist.