When BBC Investigations correspondent Noel Titheradge first started looking into this story, he set about finding insiders who knew what had gone on inside the pharmaceutical companies that made them. He contacted former staff and officials, cold called potential whistleblowers - and then he got lucky.

Someone shared an internal report from the drug company GlaxoSmithKline which revealed that they’d been aware of fifteen cases of “increased libido” in patients taking their dopamine agonist Ropinirole, including cases of paedophilia and indecent behaviour.

The report had been published in 2003, three years before warnings appeared on patient leaflets - and thirteen years before Steve started taking the drug.

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