There is quite a bit written about dopamine, with a focus on its role in the body’s reward system. Links are drawn to addiction, and drugs such as cocaine and amphetamine, which are described as providing powerful dopamine surges. As someone with Parkinson’s, you are deficient in dopamine and take medication to treat this. How does this relate to the reward system and the other functions that dopamine performs?

A lack of dopamine causes various Parkinson’s symptoms because dopamine is used in many different systems in the brain; for example, it affects mobility, but also leads to increased anxiety or sensitivity to stress. This is, in principle, the opposite of feeling satisfied, so there is a link to the reward system here. Parkinson’s medicines, which in various ways compensate for the dopamine deficiency, therefore improve well-being, usually in a ‘moderate’ way, but sometimes people can suffer from so-called ‘impulse control disorders’, which involve an increased tendency to become ‘hooked’ on something that feels rewarding. Well-known examples of this include an increased interest in gambling, sex, treats, shopping or certain work tasks, but also taking an overdose of Parkinson’s medication in search of a ‘high’. It is good to be aware that such side effects exist, and they are particularly common with dopamine agonists. Another opposite of feelings of pleasure is, of course, low mood or depression. Such problems are often treated with antidepressants. /Dag Nyholm