Biological Approach to Addiction
- Addicts inherit genetic predisposition to developing an addiction.
- Multiple genes involved - particularly A1 variant of DRD2 gene (involved in regulation of dopamine levels). This increases people's sensitivity to action of dopamine.
- SLC6A3-9 gene (removes dopamine from the synapse) involved in addiction.
- Meso-limbic dopamine system - to do with memory, reward and motivational processes - involved with maintaining an addictive behaviour.
- Normal activity = cells in meso-limbic dopamine system release small amounts of dopamine into the synapse.
- Addictive substances and behaviours increases dopamine levels in synapse.
- Addicts continue addictive behaviour because in order to experience highs from the addiction, they need to maintain high levels of dopamine (tolerance)
- Falling levels of dopamine = withdrawal symptoms
- People more susceptible to addictions may have inherited a more sensitive meso-limbic dopamine system.
- Substances (e.g nicotine) activate dopamine reward pathway and brain adapts to be in balance when substance is present (neuroadaptation)
- When substance discontinued, neuroadaptation no longer needed = withdrawal symptoms (unpleasant, immediately relieved by using substance)
Evaluation of the Biological Approach
- Compared with other approaches the biological model does not explain initiation as well as the behavioural and/or cognitive approach
- Has led to effective treatments e.g Nicotine Replacement Therapy for smoking
- Absolves addicts of responsibility - if the causes of addiction are due to genes or dopamine levels, this means the addict is releived of responsibility for the addiction so treatment is less likely to…