Website of Ruth J. van Holst
Research Mission

By studying loss of control over behaviour from a neurocognitive approach, novel insight into behavioural addictions are provided, which potentially contribute to the development of new therapeutic approaches.

Current research questions include: 

Is pathological gambling accompanied by abnormal dopamine transmission and is this associated abnormalities in reward and loss sensitivity?

The reinforcing effect of gambling has been associated with bursts of dopamine in the motivational system of the brain, analogue to drug addiction. There is circumstantial evidence that pathological gambling is accompanied by abnormal dopamine transmission and distorted reward and loss sensitivity. The next step will be to investigate the relationship between dopamine and reward and loss sensitivity in gamblers.

 

What is the role of orexin in food-related motivation and self-control?

Orexin (i.e. hypocretin) plays an important role in food-intake, reward and motivation. Orexin enhances dopamine signalling in the meso-limbic pathway that regulates reward processing and addiction. Animal studies have shown that when orexin is blocked in the meso-limbic pathway, addicted animals will stop drug-seeking behaviour.  Interestingly, there is clinical evidence that patients with narcolepsy, who are lacking orexin, suffer from decreased general motivation and interestingly; despite the fact that narcoleptic patients are usually treated with amphetamine-like compounds they rarely develop drug dependency to their medication. Paradoxically, narcolepsy is associated with a global increased frequency of obesity. In collaboration with Sebastiaan Overeem and Esther Aarts we investigate the neurocognitive mechanisms related to the disturbed food-related motivation and self-control in healthy controls and narcolepsy patients