Impulse control disorders are a common side effect of dopamine agonist drugs - it’s generally accepted that they will affect around 1 in 6 people taking these drugs for Parkinson’s.

So why are these side effects so hard to talk about? How can people get past their guilt and shame to access the support they need?

And if subtle changes in the activity of chemicals in our brain can cause us to behave so differently - what is personality?

Details of organisations offering help and support with some of the issues raised are available at bbc.co.uk/actionline.

If you have any concerns about medication you’re taking, speak to your doctor.

Presenter: Noel Titheradge