Is it possible that a pill prescribed by your doctor can turn you into a killer? Over 40 million prescriptions for SSRI antidepressants were handed out by doctors last year in the UK. Panorama reveals the devastating side effects on a tiny minority that can lead to psychosis, violence, murder and possibly even mass murder. With exclusive access to psychiatric reports, court footage and drug company data, reporter Shelley Jofre investigates the mass killings at the 2012 midnight premiere of a Batman movie in Aurora, Colorado. A 24-year-old PhD student James Holmes, who had no record of violence or gun ownership, murdered 12 and injured 70. Did the SSRI antidepressant he had been prescribed play a part in the killings? Panorama has uncovered other cases of murder and extreme violence which could be linked to psychosis developed after the taking of SSRIs, including a father who strangled his 11-year-old son. Panorama asks if enough is known about this rare side effect.