Risk factors in developing addiction

Genetic vulnerability

The idea that inherited characteristics increases the chances of developing addictions. Can be measured through twin studies and the genotype

Genetic vulnerability (AO1) - Twin Studies

Slutske et al. (2010)

• Interviewed 2889 pairs of twins to investigate the role of genetic and environmental factors in the development of gambling addictions.

• Heritability rate is the chance both twins become pathological gamblers

• Male MZ twins had a heritability rate of 49%, meanwhile DZ twins had a rate of 21%.

• Female MZ twins had a rate of 55% whilst DZ twins had a rate of 21%

• Supports the theory of genetic vulnerability as MZ twins share 100% of their DNA, so makes sense to have higher heritability rates

Genetic vulnerability (AO1) - Genotype

Noble et al. (1993)

• Referred to DRD2 gene as the reward gene

• A different allele of this gene (DRD2-A1) was more common in addicts compared to other variants

• DRD2-A1 causes fewer dopamine receptors in the brain making addictions more likely to develop as they get less pleasure from regular activities

Genetic Vulnerability (AO3) - Nature v Nurture

• There must be some environmental factors affecting addiction development as the concordance rates between MZ twins would be 100% otherwise, as they have the same DNA

Vink et al. (2005)

• Studied 1572 twin pairs

• Individual differences in smoking initiation was explained by genetic (44%) and environmental (56%) influences

• The likelihood of becoming addicted was mainly influenced by genetic (75%) influences

• Environmental factors are more responsible for beginning addictive behaviours

• Genetic factors are more responsible for maintaining addictions

Genetic Vulnerability (AO3) - Reliability

Comings et al. (1996)

• Also found that DRD2-A1 was more common in smokers, pathological gamblers and alcoholics

Suggests the research is reliable as both researchers replicated the same results and came to the same conclusions.

Genetic Vulnerability (AO3) - Real life applications

• Increases awareness of genetic vulnerability as a risk factor with the idea it might run in the family. Those who know they have a vulnerability might abstain from addictive substances

Genetic Vulnerability (AO3) - Not the only factor

Stress

A state of mental or emotional strain from adverse circumstances. Can be a risk factor through the impacts of self medication and early childhood trauma

Stress (AO1) - Self Medication

The individual isn’t coping with their stress properly, and use drugs to reduce the effects of stress

Khantzian (1985)

• The self medication hypothesis suggests that addictive behaviours develop as a treatment for stress.

Sinha (2000)

• Found addicts often relapse as a result of stressful situations. An addict will use drugs as a treatment for stress. However there are mediating factors that can change the way someone copes with stress - if someone has social support or other ways of coping with stress they will not self medicate. It may not be the level of stress that is a risk factor, but instead the ability to cope with stress.

Stress (AO1) - Early childhood trauma

Kessler et al. (1995)

• Found that for men with a history of PTSD, 34% reported drug abuse at some point in their lives, compared to 15% of men without PTSD

• Found that for women with a history of PTSD, 27% reported drug abuse at some point in their lives, compared to 8% of women without PTSD

Krosten et al. (2000)

• Newborn rats who were subject to isolation stress for an hour a day for their 2nd to 9th days of life were more likely to self-administer cocaine when they became adults

• However there is an issue with extrapolation as addiction to rats is different to humans. Rats can’t understand the negative impacts of cocaine the way humans can. The rats were also isolated in cages meaning the only stimulus they had was the cocaine which would make them more likely to use it

Stress (AO3) - Correlation does not equal causation

Stress can cause addiction, but addiction can also cause stress.

Koob and Le Moal (1997)

• Suggests stress acts as an anti-reward system. Constant drug use leads to periodic surges of dopamine and the body will try to maintain itself by homeostasis, by decreasing dopamine levels and activating stress systems in the amygdala.

• Drug use can relieve stress in the short term as withdrawal symptoms are removed, but can cause chronic stress in the long term as stress systems are constantly being activated

Stress (AO3) - Practical application

If addiction is a consequence of the experience of stress than those that develop effective coping strategies for stress are less likely to show addictive behaviours

Matheny and Weatherman (1998)

• Investigated 263 smokers who completed a national smoking cessation program, and found there was a strong relationship between participants’ use of coping resources and their ability to maintain abstinence from smoking

• This suggests that stress management techniques are an effective strategy in predicting abstinence maintenance

Stress (AO3) - Stress not the only factor

Personality