"This is surprising because PD patients typically have a very low incidence of drug abuse and display a personality type that is the opposite of the typical addictive personality. These rare, addictive syndromes, which appear to result from excessive dopaminergic treatment, illustrate the link between dopamine, personality and addiction."
PD patients treated with dopamine agonists had an incidence of pathological gambling as high as 8% compared to less than 1% in the general population. In PD patients who develop addictive disorders, the problems started soon after starting dopaminergic therapy and stopped after treatment was discontinued. It was found that adjusting the dosage and combination of medication resolved the addictive symptoms, while maintaining the same motor benefit.
The phenomenon of addiction induced by dopamine medications can also tell us something about vulnerability to addiction in the general population. Not everyone is equally vulnerable, and it now appears that the propensity to become addicted is in part hereditary. Many of the genes implicated in addiction appear to affect brain levels of dopamine.
Studies show that that dopamine acts in an area of the brain known as the ventral striatum, which receives input from other areas such as the hippocampus and amygdala. It may be through this region that dopamine promotes addictive behaviours.
Understanding brain function that leads to drug addiction may help in the development of drugs to block drug-craving and drug-seeking behaviours in the general population as well as refine disease treatment for Parkinson's patients.
|Contact: Anita Kar|