Parkinson's patients seem to have more difficulties than healthy people to trust others. This is demonstrated by a current study, which was presented at the 21st World Congress of Neurology in Vienna. Presently, more than 8,000 experts are discussing the latest developments in this specialty field.

"Particularly those brain areas that regulate trust behaviour are affected by the disease: the basal ganglia of the cerebrum, the frontal cortex and the limbic system. Moreover, dopamine and serotonin, neurotransmitters positively related to trust, are reduced when suffering from Parkinson's disease. It can therefore be assumed that various neuropsychiatric problems of the affected people may be related to exaggerated distrust due to the disease," study author Dr Andrija Javor (General Hospital Linz, Austria) explained.

To verify the hypothesis of lack of trust, the behaviour of ten female and ten male Parkinson's patients on dopaminergic treatment and slightly advanced state of the disease was studied, using a computer game and compared with the behaviour of 20 healthy controls. The game aimed to entrust an amount up to 10 Euros to a neutral "trustee". The healthy controls would give an average amount of 5,50 Euros to the virtual trustee, while the Parkinson's patients were a lot more reserved with an amount of 3,40 Euros.

"However this has nothing to do with reduced risk-appetite", stressed Dr Javor. Since later on, when playing the dice game, Parkinson's patients were the daring ones. During the game they took, in average, about ten risky decisions, while the healthy controls only took seven. "Although further research in this area is needed, the findings are already contributing to a better understanding of the problems of Parkinson's patients", according to the expert.