1. Warning Signs

2. Wonder drugs


3. Dopamine Hits


4. Big Pharma, Big Secret


5. Restless


6. Chasing Losses


16 February 2026


When Freddie's papa Bill is diagnosed with Parkinson's, his medication gives him a new lease of life. He starts ticking things off his retired person bucket list - taking a trip, sky diving, golf.


But then Freddie notices that his formerly sensible dad has actually begun behaving unusually.


BBC Investigations correspondent Noel Titheradge has spent more than a year speaking to people whose behaviour changed drastically after taking a classification of prescription drugs called dopamine agonists.


These drugs enhance dopamine activity in the brain - they were more than 1.5 million times in the UK in 2015 to deal with Parkinson's disease and other motion conditions.


But they have well established negative effects - around 1 in 6 people who take them establish impulse control disorders, which can consist of hypersexuality, binge consuming, compulsive gaming and shopping.


If these adverse effects have been understood about for years, why weren't some patients and their families appropriately warned or kept an eye on?