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 father Bill is detected with Parkinson's, his medication gives him a new lease of life. He starts ticking things off his retiree pail list - travelling, skydiving, golf.


But then that his formerly sensible dad has started behaving unusually.


BBC Investigations reporter Noel Titheradge has invested more than a year speaking with people whose behaviour altered radically after taking a classification of prescription drugs called dopamine agonists.


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


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


If these side results have been understood about for decades, why weren't some clients and their families appropriately warned or kept an eye on?